Which test is the GOLD STANDARD for diagnosing Cushing's syndrome?

Pheochromocytoma is best diagnosed by which laboratory tests?

Primary hypothyroidism shows which laboratory pattern?

Normal serum calcium, phosphate, and PTH relationship: in PRIMARY hyperparathyroidism:

The C-peptide test is used to distinguish which two causes of hypoglycemia?

ANA (Anti-Nuclear Antibody) test — which pattern is associated with SLE and how is it performed?

Rheumatoid Factor (RF) and anti-CCP antibodies in rheumatoid arthritis:

Complement system: C3 and C4 levels in SLE vs hereditary angioedema (HAE):

ANCA (Anti-Neutrophil Cytoplasmic Antibodies): cANCA vs pANCA patterns and their clinical associations:

Coombs test (Direct and Indirect): what is the antihuman globulin (AHG) reagent and how does it work?

Tumor markers: What is the main limitation of tumor markers in cancer diagnosis?

HLA (Human Leukocyte Antigen) typing is performed for which clinical purposes?

Synovial fluid analysis: how do you differentiate septic arthritis from gout?

Pleural fluid analysis — Light's criteria to distinguish exudate from transudate:

Urine analysis for BENCE JONES PROTEIN — which test is used and what is the clinical significance?

Which test is used for diagnosing Paroxysmal Nocturnal Hemoglobinuria (PNH)?

What is the Protein C, Protein S, and Antithrombin III system in coagulation?

Glucose-6-Phosphate Dehydrogenase (G6PD) deficiency testing — when should G6PD be tested?

What is the Thalassemia trait (carrier) pattern on hemoglobin electrophoresis?

Lupus Anticoagulant (LA) test: paradox of PROLONGED APTT in patients with THROMBOSIS (not bleeding):

Activated Protein C (APC) resistance and Factor V Leiden mutation testing:

Toxicology: which test is used for routine urine drug of abuse (DOA) screening?

Osmotic fragility test interpretation: increased vs decreased fragility — what do they indicate?

Which genetic test detects chromosomal rearrangements like BCR-ABL (Philadelphia chromosome) at the molecular level?

TORCH infections in pregnancy — what do the tests diagnose?

Which test is used for prenatal diagnosis of genetic disorders in the first trimester?

Sweat chloride test — what is it used for and what are the diagnostic thresholds?

Cardiac biomarkers timeline after myocardial infarction (MI): correct order of rise and normalization:

Alpha-1 antitrypsin (A1AT) deficiency laboratory diagnosis and significance:

What is the Triple Test (maternal serum screening) in second trimester for Down syndrome?

Which test distinguishes between pre-renal and intrinsic renal failure?

Which staining technique is used to identify LIPIDS in tissue sections?

Alkaline phosphatase (ALP) isoenzymes — how to differentiate hepatic from bone ALP?

Galactosemia neonatal screening — which test detects it and what enzyme is deficient?

What is the function of the 'Mixing study' (mixing test) in coagulation evaluation?

According to the WORLD HEALTH ORGANIZATION (WHO) 2021 guidelines (6th edition), the lower reference limit for TOTAL SPERM MOTILITY (progressive + non-progressive) in a semen sample is:

The WHO 2021 lower reference limit for SPERM CONCENTRATION in a semen sample is:

The normal SEMEN VOLUME per ejaculate according to WHO 2021 reference values is at least:

The WHO 2021 lower reference limit for the percentage of MORPHOLOGICALLY NORMAL spermatozoa using STRICT (KRUGER) CRITERIA is:

The normal pH of semen is approximately:

Semen LIQUEFACTION normally occurs within how many minutes of ejaculation?

AZOOSPERMIA is defined as:

OLIGOZOOSPERMIA is the term used when sperm concentration falls below the WHO 2021 lower reference limit. Which of the following CORRECTLY defines severe oligozoospermia?

FRUCTOSE is a biochemical marker in semen analysis. What is the clinical significance of ABSENT or VERY LOW FRUCTOSE in semen?

ACID PHOSPHATASE is a biochemical marker in semen produced by which gland and what is its diagnostic significance?

The RECOMMENDED ABSTINENCE PERIOD before semen collection for analysis is:

TERATOZOOSPERMIA is defined as having less than 4% morphologically normal sperm. Which sperm HEAD DEFECT is characterized by complete absence of the ACROSOME, resulting in globular (round) shaped heads?

ASTHENOZOOSPERMIA is defined by reduced sperm MOTILITY. According to WHO 2021, total motility less than what percentage defines asthenozoospermia?

The HYPO-OSMOTIC SWELLING (HOS) TEST evaluates sperm membrane INTEGRITY. Which result indicates viable (living) spermatozoa?

LEUKOCYTOSPERMIA (pyospermia) is defined as an elevated number of WHITE BLOOD CELLS in semen. According to WHO, the threshold for leukocytospermia is:

The EOSIN-NIGROSIN staining technique in semen analysis is used to determine:

HAEMATOSPERMIA refers to the presence of which abnormal finding in semen?

The MIXED ANTIGLOBULIN REACTION (MAR) test detects ANTI-SPERM ANTIBODIES (ASA). In a POSITIVE MAR test, what is observed?

RETROGRADE EJACULATION is confirmed by finding spermatozoa in which sample collected AFTER ejaculation?

ZINC is an important marker in semen analysis. Which gland produces ZINC and what is its significance?

SPERM AGGLUTINATION in semen refers to which observation and what is its clinical relevance?

SPERM DNA FRAGMENTATION (SDF) testing evaluates the integrity of DNA within spermatozoa. What is the most commonly used test for sperm DNA fragmentation in clinical practice?

The MAKLER COUNTING CHAMBER is specifically designed for semen analysis. What is the DEPTH of the Makler chamber?

IMMATURE GERM CELLS (spermatogenic cells) in the ejaculate can be confused with leukocytes on a wet preparation. Which test specifically DIFFERENTIATES IMMATURE GERM CELLS from WHITE BLOOD CELLS in semen?

KLINEFELTER SYNDROME is the most common GENETIC CAUSE of male infertility (testicular azoospermia). What is the KARYOTYPE of Klinefelter syndrome?

COMPUTER-ASSISTED SPERM ANALYSIS (CASA) provides objective measurements of sperm VELOCITY. Which parameter measures the AVERAGE SPEED of the sperm head along its ACTUAL CURVILINEAR PATH?

OLIGOASTHENOTERATOZOOSPERMIA (OAT syndrome) refers to a semen abnormality where which combination of parameters is affected?

ALPHA-GLUCOSIDASE in semen is a biochemical marker produced by which structure and what is its significance?

OXIDATIVE STRESS in semen is measured by assessing REACTIVE OXYGEN SPECIES (ROS). Which of the following tests measures TOTAL ROS PRODUCTION in semen?

NECROZOOSPERMIA is defined as the condition where MOST spermatozoa are non-viable (dead). The WHO 2021 lower reference limit for SPERM VITALITY (percentage of live sperm) is:

The APPEARANCE and CONSISTENCY of semen are macroscopic parameters. What is the NORMAL color of semen?

SEMEN VISCOSITY is assessed macroscopically. Abnormally HIGH viscosity (hyperviscosity) in semen is associated with which condition and what is the consequence?

PAPANICOLAOU STAINING of sperm smears is the WHO-recommended method for assessing sperm MORPHOLOGY. What color do the sperm HEADS appear with PAP stain?

The NORMAL SPERM has a characteristic STRUCTURE. Moving from head to tail, what is the CORRECT ORDER of sperm anatomical segments?

CRYPTORCHIDISM (undescended testis) is a risk factor for male infertility. If BILATERAL CRYPTORCHIDISM is NOT corrected before puberty, what is the expected effect on SEMEN PARAMETERS?

IMMOTILE CILIA SYNDROME (Primary Ciliary Dyskinesia — PCD) causes male infertility through a specific structural defect. Which is the MOST COMMON ultrastructural defect in PCD?

According to WHO 2021, what is the minimum number of spermatozoa that should be evaluated when assessing SPERM MOTILITY on a semen smear?

SPERMATOGENESIS (sperm production) from SPERMATOGONIUM to SPERMATOZOON takes approximately how many days in humans?

CAPACITATION is an important process that spermatozoa must undergo before they can fertilize an egg. Where does capacitation naturally occur?

POST-TESTICULAR OBSTRUCTION is a common cause of obstructive azoospermia. Which biochemical COMBINATION in semen analysis most strongly suggests EJACULATORY DUCT OBSTRUCTION?

SPERM CAPACITATION is distinguished from the ACROSOME REACTION. The ACROSOME REACTION is triggered by which specific stimulus in vivo?

A VARICOCELE is an abnormal dilation of the PAMPINIFORM PLEXUS of veins in the scrotum. On which SIDE is varicocele MORE COMMONLY found?

The PSA (PROSTATE-SPECIFIC ANTIGEN) has a DUAL ROLE — clinically as a PROSTATE CANCER MARKER and in semen analysis. What is PSA's specific ROLE IN SEMEN?

What is the clinical significance of detecting IMMATURE SPERMATIDS (round spermatids or elongated spermatids) in the ejaculate on semen analysis?

SEMEN CRYOPRESERVATION (sperm banking) is recommended before which of the following procedures?

SELIWANOFF'S TEST for FRUCTOSE in semen involves adding semen to which REAGENT, and what is the POSITIVE result?

OLIGOSPERMIA due to Y-CHROMOSOME MICRODELETIONS shows specific regions deleted. Which Y-chromosome region deletion (AZF region) is associated with the WORST prognosis for sperm retrieval?

FOLLICLE STIMULATING HORMONE (FSH) level in the blood of an infertile male provides important information about the CAUSE of azoospermia. ELEVATED FSH in azoospermia indicates:

NORMOZOOSPERMIA is defined as semen with ALL parameters meeting the WHO lower reference limits. Which of the following sets of values represents NORMOZOOSPERMIA according to WHO 2021?

TESTICULAR BIOPSY for azoospermia can show several histological patterns. The pattern where seminiferous tubules contain ONLY SERTOLI CELLS with no germ cells is called:

A normal adult produces approximately how much urine over a 24-hour period?

The SPECIFIC GRAVITY of normal urine typically ranges between:

The normal pH of urine ranges from:

The color of NORMAL urine is described as pale yellow to amber. The color is primarily due to:

PROTEINURIA is defined as excessive protein in the urine. What is the normal upper limit of protein excretion in urine over 24 hours?

The DIPSTICK test for PROTEIN in urine primarily detects which protein?

BENCE JONES PROTEIN in urine has a characteristic thermal property. What happens to Bence Jones protein when urine is gradually HEATED and then COOLED?

GLUCOSURIA (glucose in urine) is most commonly detected by the GLUCOSE OXIDASE dipstick test. At what blood glucose level does glucosuria typically FIRST APPEAR in a normal person?

REDUCING SUBSTANCES in urine that cause a POSITIVE BENEDICT'S TEST but NEGATIVE GLUCOSE OXIDASE TEST include which of the following?

KETONURIA (ketone bodies in urine) is detected on dipstick. The dipstick for ketones primarily detects which ketone body?

BILIRUBINURIA (bilirubin in urine) is detected by the dipstick test. Which form of bilirubin is normally excreted in urine?

UROBILINOGEN in urine is produced from which metabolic pathway and when is it ABSENT from urine?

HEMATURIA is detected by urine dipstick. The dipstick for BLOOD cross-reacts with which other substances causing FALSE POSITIVE results?

NITRITE on the urine dipstick indicates:

LEUKOCYTE ESTERASE on the urine dipstick detects:

MICROSCOPIC EXAMINATION of urine: which type of CAST is considered PATHOGNOMONIC of ACUTE TUBULAR NECROSIS (ATN)?

DYSMORPHIC red blood cells in urine microscopy (seen on phase-contrast microscopy) indicate bleeding from which location?

PYURIA is defined as an abnormal number of white blood cells in urine. The threshold for significant pyuria on microscopy is:

URINE CRYSTALS are identified on microscopy. CALCIUM OXALATE crystals in urine have which characteristic MORPHOLOGY?

The URINE OSMOLALITY of a HEALTHY PERSON after OVERNIGHT WATER DEPRIVATION should be at minimum:

MICROALBUMINURIA (now termed low-grade albuminuria) is defined by the urine albumin-to-creatinine ratio (UACR). What is the range for this condition?

NEPHROTIC SYNDROME produces characteristic changes in urine analysis. Which combination of findings is PATHOGNOMONIC of nephrotic syndrome?

A urine sample that appears CLOUDY/TURBID on macroscopic examination. What are the most common CAUSES of turbid urine?

RENAL TUBULAR ACIDOSIS (RTA) is a group of disorders affecting urinary acidification. Which type of RTA produces HYPOKALEMIA + INABILITY TO ACIDIFY URINE BELOW pH 5.5 despite systemic acidosis?

PORPHYRIA is a group of metabolic disorders affecting heme synthesis. Which urine finding is characteristic of ACUTE INTERMITTENT PORPHYRIA (AIP)?

ALKAPTONURIA is caused by deficiency of which enzyme and what characteristic urine finding helps diagnose it?

The FIRST MORNING URINE SPECIMEN is preferred for many urine tests. Why is it considered the BEST specimen for detecting proteinuria and casts?

A PREGNANCY TEST detects which hormone in urine?

ORTHOSTATIC PROTEINURIA is a benign condition in young people. How is it diagnosed?

A urine specimen that has been left unrefrigerated for MORE THAN 2 HOURS will show which FALSE results on microscopy and dipstick?

URINE CREATININE measurement is used for which purposes in clinical pathology?

Urine examination for TUBERCULOSIS requires which specific test?

URINE CULTURE is the GOLD STANDARD for diagnosing urinary tract infection. What colony count defines SIGNIFICANT BACTERIURIA?

What is the MOST COMMON cause of RENAL CALCULI (kidney stones) worldwide?

The OSMOLAL GAP in urine is used to diagnose which condition?

URINE CYTOLOGY is performed for detection of which malignancy?

URINE CALCIUM excretion is elevated in HYPERCALCIURIA. What is the normal upper limit of urine calcium excretion per day?

URINARY URIC ACID excretion is assessed in patients with GOUT and uric acid stones. What is the daily upper normal limit for uric acid in urine?

PHENYLKETONURIA (PKU) is a metabolic disorder detectable through urine examination. What is the urine finding in classical PKU?

The DIPSTICK TEST FOR LEUKOCYTE ESTERASE is positive. Urine microscopy shows EOSINOPHILS predominantly. Which diagnosis should be strongly considered?

URINE CYTOLOGY for MALIGNANT CELLS uses specific collection methods. Which is the BEST type of urine specimen for maximizing malignant cell yield?

MAPLE SYRUP URINE DISEASE (MSUD) is caused by deficiency of which enzyme and how is it detected on urine testing?

Which URINE TEST is used to diagnose PHEOCHROMOCYTOMA (adrenal medullary tumor)?

URINARY 5-HIAA (5-hydroxyindoleacetic acid) is a tumor marker in urine used to diagnose which condition?

HEMATURIA can be classified as GROSS (macroscopic) or MICROSCOPIC. What is the threshold for significant MICROSCOPIC hematuria on a properly collected specimen?

URINE AMINO ACID ANALYSIS: In CYSTINURIA, which amino acids are excessively excreted in urine (beyond cystine alone)?

URINE VANILLYLMANDELIC ACID (VMA) measurement is used for diagnosing which condition in children?

POLYURIA (urine output > 3 L/day) with LOW URINE OSMOLALITY despite high PLASMA OSMOLALITY is characteristic of which condition?

FIBRIN DEGRADATION PRODUCTS (FDPs) in urine can be elevated in which conditions?

UROFLOWMETRY is a urodynamic test. What does it measure and in which condition is the maximum urinary flow rate (Qmax) REDUCED?

The NORMAL volume of cerebrospinal fluid (CSF) in the entire central nervous system of an adult is approximately:

The procedure for collecting CSF is LUMBAR PUNCTURE. At which VERTEBRAL LEVEL is it typically performed in adults to avoid spinal cord injury?

The NORMAL appearance of CSF is:

The NORMAL CELL COUNT in CSF is:

The NORMAL CSF PROTEIN concentration in adults is:

The NORMAL CSF GLUCOSE is expressed as a ratio to PLASMA GLUCOSE. What is the normal CSF-to-plasma glucose ratio?

BACTERIAL MENINGITIS produces a characteristic CSF profile. Which combination of findings is MOST typical of ACUTE BACTERIAL MENINGITIS?

TUBERCULOUS MENINGITIS (TBM) has specific diagnostic markers in CSF. Which CSF test has the highest SENSITIVITY for TBM diagnosis?

INDIA INK PREPARATION of CSF is used to diagnose infection with which organism?

VIRAL MENINGITIS produces a distinctive CSF pattern. Which parameter most RELIABLY differentiates viral from bacterial meningitis?

XANTHOCHROMIA in CSF is most reliably detected by which method?

OLIGOCLONAL BANDS (OCBs) in CSF are an important finding in which neurological disorder?

NEUROSYPHILIS can be diagnosed using which specific TREPONEMA-SPECIFIC CSF test?

MALIGNANT MENINGITIS (Leptomeningeal carcinomatosis) produces a typical CSF finding. Which test is the GOLD STANDARD for its diagnosis?

GUILLAIN-BARRÉ SYNDROME (GBS) has a characteristic CSF finding called ALBUMINOCYTOLOGICAL DISSOCIATION. What does this term mean?

CSF TAU PROTEIN and AMYLOID BETA-42 are biomarkers for which neurodegenerative condition?

The CSF in HERPES SIMPLEX ENCEPHALITIS (HSE) shows which characteristic features?

Eosinophilic pleocytosis in CSF (> 10% eosinophils) is most commonly associated with which organism?

CSF LACTATE measurement is useful for differentiating bacterial from viral meningitis. What is the THRESHOLD LEVEL above which bacterial meningitis is strongly supported?

NORMAL PRESSURE HYDROCEPHALUS (NPH) is a clinical syndrome of the elderly. What is the characteristic CSF FINDING on lumbar puncture?

CSF PROCALCITONIN is useful for differentiating bacterial from viral meningitis. Which statement is CORRECT about CSF procalcitonin?

CSF examination in MULTIPLE SCLEROSIS (MS): which combination of findings supports the diagnosis?

A 25-year-old presents with thunderclap headache (worst-of-life). CT head is performed and is NEGATIVE. How long after the headache onset should the LP ideally be performed to MAXIMIZE SENSITIVITY for SAH detection?

CREUTZFELDT-JAKOB DISEASE (CJD) is a prion disease with unique CSF biomarkers. Which combination best supports the diagnosis?

In the CSF, the OPENING PRESSURE is measured. What is the NORMAL RANGE and what indicates RAISED INTRACRANIAL PRESSURE (ICP)?

PARTIALLY TREATED BACTERIAL MENINGITIS poses diagnostic challenges. Which CSF finding is MOST RESISTANT to change after antibiotic treatment (and therefore most useful for diagnosis)?

NEUROMYELITIS OPTICA SPECTRUM DISORDER (NMOSD) is distinct from MS. Which SPECIFIC ANTIBODY in CSF/serum differentiates NMOSD from MS?

When collecting CSF for MICROBIOLOGICAL ANALYSIS, what is the MINIMUM VOLUME recommended for bacterial culture?

LISTERIA MONOCYTOGENES meningitis has characteristic CSF findings that differ from typical bacterial meningitis. Which feature is most distinctive?

CSF ADENOSINE DEAMINASE (ADA) is a useful marker. In which CONDITION is CSF ADA MARKEDLY ELEVATED?

AUTOIMMUNE ENCEPHALITIS (specifically anti-NMDAR encephalitis) shows which CSF findings?

CSF GLUCOSE is measured. A patient has a blood glucose of 18 mmol/L (diabetic) and CSF glucose of 9 mmol/L. Is the CSF glucose normal or abnormal?

A SPINAL CORD COMPRESSION causes a characteristic CSF pattern called FROIN'S SYNDROME. Which finding specifically characterizes this syndrome?

ENCEPHALITIS differs from MENINGITIS. In ENCEPHALITIS, which additional laboratory finding is most diagnostically helpful?

In laboratory processing of CSF, what should be done with a CSF specimen if it CANNOT be processed immediately?

CRYPTOCOCCAL MENINGITIS in an HIV patient: the CrAg (cryptococcal antigen) titer in CSF correlates with what clinical parameter?

TRAUMATIC LUMBAR PUNCTURE produces blood-contaminated CSF. Which finding MOST RELIABLY distinguishes a traumatic tap from TRUE SUBARACHNOID HEMORRHAGE?

SUBACUTE SCLEROSING PANENCEPHALITIS (SSPE) is a fatal late complication of measles infection. Which CSF finding is CHARACTERISTIC of SSPE?

A child with HYDROCEPHALUS has a VENTRICULOPERITONEAL (VP) SHUNT. The shunt appears infected. CSF is obtained by TAP of the shunt reservoir. Which organism is MOST COMMONLY responsible for VP SHUNT INFECTIONS?

CSF OPENING PRESSURE is elevated to > 400 mmH₂O in an obese young woman with headache and papilledema but otherwise NORMAL CSF. Which MEDICATION is commonly associated with causing this condition?

RHEUMATOID ARTHRITIS (RA) can cause RHEUMATOID MENINGITIS. Which CSF finding is characteristic of this rare complication?

When interpreting the CSF CELL DIFFERENTIAL in bacterial meningitis, what change occurs during the HEALING PHASE as the patient responds to antibiotics?

NEISSERIA MENINGITIDIS meningitis in teenagers is preventable. Which CSF Gram stain finding is CHARACTERISTIC of meningococcal meningitis?

CSF ANALYSIS in a NEONATE with suspected meningitis: how do NORMAL VALUES differ from those in adults?

LYME NEUROBORRELIOSIS (Lyme disease affecting the nervous system) produces which characteristic CSF finding?

AMOEBIC MENINGOENCEPHALITIS is a rare but almost universally fatal condition caused by which free-living amoeba?

SPINAL ARACHNOIDITIS causes characteristic CSF changes. Which finding supports this diagnosis?

CSF NEUROFILAMENT LIGHT CHAIN (NfL) is a biomarker for which pathological process?

VENTRICULITIS (infection of the brain ventricles) can complicate external ventricular drains (EVDs). Which CSF parameter is most reliable for diagnosing EVD-related ventriculitis?

A comprehensive SUMMARY: Which CSF profile is MOST CONSISTENT with FUNGAL MENINGITIS (Cryptococcus)?

A normal STOOL EXAMINATION begins with MACROSCOPIC (physical) assessment. What is the NORMAL consistency and color of stool?

FAECAL OCCULT BLOOD TESTING (FOBT) detects hidden blood in stool. The GUAIAC-BASED test (gFOBT) relies on which chemical principle?

In stool examination, MUCUS in the stool indicates inflammation of which part of the gut?

STEATORRHOEA (fat malabsorption) is detected by which specific STOOL TEST?

ENTAMOEBA HISTOLYTICA is detected in stool examination. What is the DIAGNOSTIC FORM of E. histolytica that must be identified in symptomatic infection?

GIARDIA LAMBLIA (Giardia intestinalis) infection is detected in stool. What are the CHARACTERISTIC forms found on stool examination?

CRYPTOSPORIDIUM PARVUM is an important gut pathogen especially in immunocompromised patients. How is it identified on stool examination?

ASCARIS LUMBRICOIDES eggs are identified in stool microscopy. What is the CHARACTERISTIC MORPHOLOGICAL feature of fertilised Ascaris eggs?

HOOKWORM infection (Ancylostoma and Necator) is identified by finding EGGS in stool. What is the characteristic morphology of hookworm eggs?

TRICHURIS TRICHIURA (whipworm) eggs have a distinctive morphology. What is their CHARACTERISTIC APPEARANCE?

ENTEROBIUS VERMICULARIS (pinworm/threadworm) infection is diagnosed by which SPECIFIC DIAGNOSTIC TEST rather than routine stool examination?

STRONGYLOIDES STERCORALIS is unique among intestinal helminths. What distinguishes it on stool examination from hookworm?

TAENIA SAGINATA (beef tapeworm) eggs are found in stool. How do they differ from TAENIA SOLIUM (pork tapeworm) eggs?

HYMENOLEPIS NANA (dwarf tapeworm) is the MOST COMMON TAPEWORM WORLDWIDE. What is the characteristic feature of its EGGS?

SCHISTOSOMA HAEMATOBIUM is identified by eggs in URINE not stool. However, SCHISTOSOMA MANSONI and SCHISTOSOMA JAPONICUM are diagnosed by eggs in STOOL. What distinguishes these two species?

BALANTIDIUM COLI is the LARGEST INTESTINAL PROTOZOAN infecting humans. On stool examination, how is it identified?

CYCLOSPORA CAYETANENSIS is an intestinal coccidian parasite. How is it distinguished from Cryptosporidium on stool examination?

FAECAL CALPROTECTIN is a non-invasive stool marker used to differentiate INFLAMMATORY BOWEL DISEASE from IRRITABLE BOWEL SYNDROME. Which of the following correctly describes its use?

FAECAL ELASTASE-1 is a stool biomarker for which condition?

CLOSTRIDIOIDES DIFFICILE (C. diff) infection is diagnosed by stool testing. What is the RECOMMENDED DIAGNOSTIC APPROACH?

CONCENTRATION TECHNIQUES are used in stool parasitology to improve detection sensitivity. Which concentration technique SEPARATES PARASITES based on SEDIMENTATION rather than flotation?

OPERCULATED EGGS in stool examination indicate which group of parasites?

REDUCING SUBSTANCES in stool are tested using CLINITEST tablets. This test is used to diagnose which condition in INFANTS?

In stool microscopy, CHARCOT-LEYDEN CRYSTALS (also called Charcot-Robin crystals) indicate the presence of which cell type?

WET MOUNT preparation of stool examines for intestinal parasites. What is the CORRECT stain used to DIFFERENTIATE protozoan cysts and identify their INTERNAL NUCLEAR STRUCTURE?

FASCIOLA HEPATICA (liver fluke) infection causes which type of STOOL FINDING and in which CLINICAL CONTEXT?

STOOL CULTURE for pathogenic bacteria is indicated in patients with suspected BACTERIAL GASTROENTERITIS. Which SELECTIVE MEDIUM is used for isolating CAMPYLOBACTER JEJUNI?

ISOSPORA BELLI (now Cystoisospora belli) is a coccidian parasite. What is the characteristic egg/oocyst morphology in stool?

A MELAENA stool is dark, tarry, and offensive-smelling. What is the MINIMUM VOLUME of blood loss from the UPPER GASTROINTESTINAL TRACT required to produce melaena?

NORWALK VIRUS (Norovirus) is the most common cause of VIRAL GASTROENTERITIS worldwide. How is it diagnosed from stool?

DIPHYLLOBOTHRIUM LATUM (broad fish tapeworm) causes which specific NUTRITIONAL DEFICIENCY?

TRICHROME (WHEATLEY) STAIN is the BEST PERMANENT STAIN for protozoan identification in stool. Which colours are produced by this stain for different cellular elements?

ENTAMOEBA COLI is a NON-PATHOGENIC commensal in the human gut. How does it differ from Entamoeba histolytica on stool examination?

TOXIN-PRODUCING E. COLI strains cause different types of diarrhoea. Which E. coli serotype causes HAEMOLYTIC URAEMIC SYNDROME (HUS) and BLOODY DIARRHOEA?

MICROSPORA (Microsporidia) are obligate intracellular parasites seen in immunocompromised patients. Which STAIN is used to identify microsporidial spores in stool?

STOOL EXAMINATION for VIBRIO CHOLERAE: which ENRICHMENT MEDIUM is used to grow V. cholerae and what are the colony characteristics on TCBS agar?

FAECAL PH is an important parameter in stool analysis. What is the NORMAL FAECAL pH in adults?

SALMONELLA TYPHI causes TYPHOID FEVER. In which WEEK of illness is STOOL CULTURE most likely to be POSITIVE?

TRICHINELLA SPIRALIS causes TRICHINELLOSIS. Stool examination is UNLIKELY to help in the diagnosis. What is the PRINCIPAL DIAGNOSTIC METHOD?

FAECAL TRANSPLANTATION (FMT — Faecal Microbiota Transplantation) is used for which PRIMARY CLINICAL INDICATION?

DIENTAMOEBA FRAGILIS is an intestinal flagellate. What is unique about its diagnostic identification on stool examination?

The HARADA-MORI FILTER PAPER CULTURE TECHNIQUE is used for which purpose in stool parasitology?

ROTAVIRUS is the most common cause of DEHYDRATING DIARRHOEA in CHILDREN under 5 years worldwide. How is it diagnosed from stool?

HUMAN INTESTINAL SPIROCHAETOSIS is caused by which organism found in stool, and what is its characteristic microscopic appearance?

PARAGONIMUS WESTERMANI (lung fluke) eggs can be found in both STOOL and SPUTUM. What is the characteristic EGG MORPHOLOGY?

STOOL NITROGEN (FAECAL NITROGEN) measurement is used in the assessment of which condition?

SHIGELLA DYSENTERY is diagnosed by stool culture. What are the SELECTIVE MEDIA used and what is the characteristic colony appearance?

SPECIMEN COLLECTION for STOOL EXAMINATION requires specific guidelines. What is the RECOMMENDED METHOD and CONTAINER for submitting stool for PARASITOLOGICAL EXAMINATION?

The COLOUR of STOOL can have diagnostic significance. ACHOLIC (PALE/CLAY-COLOURED) stools indicate which condition?

PLEURAL EFFUSION is classified as TRANSUDATE or EXUDATE using LIGHT'S CRITERIA. Which set of criteria defines an EXUDATE?

PLEURAL FLUID GLUCOSE is markedly LOW (< 3.3 mmol/L) in which conditions?

PLEURAL FLUID AMYLASE is elevated in which conditions?

EMPYEMA THORACIS is diagnosed based on pleural fluid analysis. Which PLEURAL FLUID pH indicates EMPYEMA requiring URGENT DRAINAGE?

CHYLOTHORAX is a milky pleural effusion. What is the DIAGNOSTIC TEST that confirms chyle in the pleural fluid?

ASCITIC FLUID analysis uses the SERUM-ASCITES ALBUMIN GRADIENT (SAAG) to distinguish portal hypertension from non-portal causes. What SAAG value indicates PORTAL HYPERTENSION?

SPONTANEOUS BACTERIAL PERITONITIS (SBP) is diagnosed using which ASCITIC FLUID finding?

TUBERCULOUS PERITONITIS produces ascitic fluid with which CHARACTERISTIC FINDINGS?

SYNOVIAL FLUID analysis classifies joint effusions into GROUPS. What are the four CLASSES of synovial fluid based on CELL COUNT and APPEARANCE?

CRYSTAL IDENTIFICATION in synovial fluid distinguishes GOUT from PSEUDOGOUT. What are the CHARACTERISTIC CRYSTAL FEATURES under polarised light microscopy?

The MUCIN CLOT TEST (ROPES TEST) on synovial fluid evaluates which property?

PERICARDIAL EFFUSION analysis: which CAUSE produces a haemorrhagic (bloody) pericardial effusion MOST COMMONLY?

SERUM CREATININE is used to estimate kidney function. What is the NORMAL serum creatinine range in adult males?

BLOOD UREA NITROGEN (BUN) and the BUN-TO-CREATININE RATIO are used in clinical practice. A BUN:CREATININE RATIO > 20:1 suggests which condition?

GLOMERULAR FILTRATION RATE (GFR) is the best overall measure of kidney function. What is the NORMAL GFR in a young healthy adult?

SERUM URIC ACID is measured as part of renal function tests. Normal serum uric acid levels and the threshold for HYPERURICAEMIA are:

CYSTATIN C is an alternative marker of GFR. What is its ADVANTAGE over serum creatinine for GFR estimation?

TUBULAR FUNCTION TESTS assess how well the renal tubules reabsorb filtered substances. The TUBULAR MAXIMUM FOR GLUCOSE (Tm glucose) is approximately:

The FRACTIONAL EXCRETION OF SODIUM (FENa) is used to differentiate pre-renal from intrinsic renal failure. FENa < 1% indicates which condition?

SERUM CREATININE CLEARANCE is calculated from a 24-HOUR URINE COLLECTION. What is the CORRECT FORMULA?

RENAL FUNCTION TESTS — BETA-2-MICROGLOBULIN in urine is a marker of which type of kidney dysfunction?

LIVER FUNCTION TESTS include serum ALANINE AMINOTRANSFERASE (ALT) and ASPARTATE AMINOTRANSFERASE (AST). Which is MORE SPECIFIC for LIVER DISEASE?

GAMMA-GLUTAMYL TRANSFERASE (GGT) is an enzyme used in liver function testing. Which condition most characteristically elevates GGT?

ALKALINE PHOSPHATASE (ALP) is elevated in both HEPATIC and BONE DISEASE. Which test is used to IDENTIFY THE ORGAN ORIGIN of elevated ALP?

SERUM BILIRUBIN — TOTAL, DIRECT (CONJUGATED), AND INDIRECT (UNCONJUGATED) — are measured in liver function testing. What TOTAL BILIRUBIN LEVEL causes CLINICAL JAUNDICE (visible yellowing of sclerae)?

PROTHROMBIN TIME (PT) and INR are used as a LIVER FUNCTION TEST. Why is PT a useful indicator of SYNTHETIC LIVER FUNCTION?

SERUM ALBUMIN is used as a marker of chronic liver synthetic function. What is its CLINICAL LIMITATION in assessing ACUTE LIVER FAILURE?

SERUM PROTEIN ELECTROPHORESIS identifies protein fractions. Which band on electrophoresis is ELEVATED in ACUTE PHASE RESPONSE (infection, inflammation)?

SERUM AMYLASE and LIPASE are measured for PANCREATITIS diagnosis. Which statement about their DIAGNOSTIC PERFORMANCE is CORRECT?

SERUM FERRITIN is measured as part of iron studies. What is the CLINICAL INTERPRETATION of a VERY HIGH serum ferritin (> 1000 µg/L) in a patient WITHOUT iron overload?

TRANSFERRIN SATURATION is calculated from serum iron and TIBC. What is its formula and what is the normal range?

LACTATE DEHYDROGENASE (LDH) is measured in body fluids and blood. Which specific LDH ISOENZYME is predominantly elevated in MYOCARDIAL INFARCTION?

SERUM CALCIUM — TOTAL CALCIUM interpretation requires CORRECTION for what factor?

The ANION GAP is a calculated value used in diagnosing metabolic acidosis. What is the formula and normal range?

SERUM SODIUM and OSMOLALITY: an OSMOLAL GAP is found when measured osmolality exceeds calculated osmolality by > 10 mOsm/kg. What is the MOST IMPORTANT clinical cause of a HIGH OSMOLAL GAP?

THYROID FUNCTION TESTS — TSH (thyroid stimulating hormone) is the MOST SENSITIVE screening test for thyroid disorders. Which pattern indicates PRIMARY HYPOTHYROIDISM?

PARATHYROID HORMONE (PTH) and CALCIUM relationship: in PRIMARY HYPERPARATHYROIDISM, what is the pattern of calcium and PTH?

SERUM POTASSIUM — hypokalaemia is defined as serum K⁺ < 3.5 mEq/L. Which finding on ELECTROCARDIOGRAM (ECG) is associated with hypokalaemia?

SERUM SODIUM disorders: HYPONATRAEMIA (Na < 135 mEq/L) is the most common electrolyte disorder. What is the diagnostic approach using URINE SODIUM and OSMOLALITY?

TROPONIN I or TROPONIN T — cardiac biomarkers of MYOCARDIAL INJURY. Which statement about HIGH-SENSITIVITY TROPONIN (hs-cTn) is CORRECT?

BNP (B-TYPE NATRIURETIC PEPTIDE) and NT-proBNP are biomarkers for HEART FAILURE. What is the PRIMARY CLINICAL USE of BNP measurement?

D-DIMER is measured in the investigation of suspected VENOUS THROMBOEMBOLISM (VTE). What is its PRIMARY CLINICAL UTILITY?

C-REACTIVE PROTEIN (CRP) and PROCALCITONIN (PCT) are acute phase reactants. How do they differ in GUIDING ANTIBIOTIC THERAPY in RESPIRATORY TRACT INFECTIONS?

SERUM CORTISOL and the SHORT SYNACTHEN TEST are performed to diagnose adrenal insufficiency. What defines a NORMAL RESPONSE to synacthen (synthetic ACTH)?

SERUM LIPID PROFILE includes total cholesterol, LDL-cholesterol, HDL-cholesterol, and triglycerides. The FRIEDEWALD EQUATION calculates LDL-cholesterol. What is this formula?

GLYCATED HAEMOGLOBIN (HbA1c) is used for diabetes diagnosis and monitoring. What does HbA1c MEASURE?