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PA7.1,PA22.1-5 | Diagnostic Cytology & Clinical Pathology — Graded Quiz
Graded
12 questions · Untimed · 2 attempts
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A 58-year-old man with a 40 pack-year smoking history undergoes bronchoscopy for a central endobronchial mass. Bronchial brushings yield a cytological specimen. On review, the cells show: nuclear-to-cytoplasmic ratio of approximately 1:1, coarse granular chromatin, irregular crenated nuclear membranes, distinct nucleoli, and dense orange-staining cytoplasm (orangeophilia) on Papanicolaou stain. Intercellular bridges are noted in some cell clusters. Which cytological diagnosis is MOST likely, and which SINGLE nuclear feature carries the GREATEST specificity for malignancy in this context?
A
Reactive squamous metaplasia; the most specific feature for malignancy is increased cytoplasmic keratinisation (orangeophilia) alone
B
Squamous cell carcinoma; the MOST specific nuclear criterion for malignancy is macronucleolus combined with irregular chromatin distribution (not nucleolus alone)
C
Squamous cell carcinoma; the irregular nuclear membrane (crenation/notching) combined with coarse, unevenly distributed chromatin represents the MOST specific nuclear criterion for malignancy over nucleolus size alone
✓
D
Adenocarcinoma; the orangeophilia indicates mucin secretion and the nucleoli indicate glandular differentiation; bronchial brushings reliably distinguish squamous from glandular subtypes
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A 34-year-old woman undergoes FNAC of a 3 cm right thyroid nodule. The cytology report reads: 'Cellular follicular aspirate with microfollicles and Hürthle cell change. Colloid absent. Nuclear features: ground-glass chromatin, nuclear grooves, and occasional intranuclear pseudoinclusions in some cells.' She is referred to a surgeon. Which Bethesda category best fits this report, and what is the approximate risk of malignancy in this category?
A
Bethesda III (Atypia of Undetermined Significance / Follicular Lesion of Undetermined Significance — AUS/FLUS); approximately 10-30% risk of malignancy
B
Bethesda V (Suspicious for Malignancy); approximately 60-75% risk of malignancy; the nuclear features described are suspicious for but not definitively diagnostic of papillary thyroid carcinoma
✓
C
Bethesda VI (Malignant); approximately 97-99% risk of malignancy; nuclear pseudoinclusions and grooves definitively diagnose papillary thyroid carcinoma on FNAC
D
Bethesda II (Benign); microfollicles are a common benign finding; Hürthle cell change is a reactive pattern in Hashimoto thyroiditis
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A 55-year-old man with known hypertension presents with haematuria (visible, painless, 2 weeks). Urine microscopy shows: >100 RBCs/hpf, 80% of which are dysmorphic (acanthocytes, G1 cells); 2-3 RBC casts/hpf; and 2+ protein on dipstick. His blood pressure is 175/105 mmHg. Serum creatinine is 1.9 mg/dL (baseline 0.9 mg/dL). Which statement BEST explains why dysmorphic RBCs and RBC casts point to a glomerular origin of haematuria rather than a urological source?
A
Dysmorphic RBCs result from enzymatic destruction by renal tubular lysosomes; RBC casts form only when urine pH falls below 5.0
B
Dysmorphic RBCs (especially acanthocytes/G1 cells) result from mechanical trauma as RBCs are forced under high pressure through damaged glomerular basement membrane pores and subjected to osmotic stress in the tubule; RBC casts form when Tamm-Horsfall protein (uromodulin) precipitates in the tubule lumen, incorporating glomerular-origin RBCs
✓
C
Dysmorphic RBCs indicate renal vein thrombosis causing venous congestion; RBC casts form from coagulation of blood in the urinary collecting system due to bladder injury
D
Dysmorphic RBCs result from complement-mediated RBC fragmentation at the tubular level in any cause of haematuria; casts can form from transitional cell tumour debris in the collecting system
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A 70-year-old woman with type 2 diabetes and stage 3 CKD presents with sudden-onset confusion, fever (38.7°C), and dysuria for 3 days. Urine dipstick: LE 3+, nitrite positive, blood 2+, protein 2+. Urine microscopy: 80 WBCs/hpf (predominantly PMNs), 15 RBCs/hpf (isomorphic), WBC casts present, granular casts 2-5/hpf. Culture pending. Which single finding MOST specifically indicates the infection has ascended to the renal parenchyma rather than remaining confined to the bladder?
A
Leucocyte esterase 3+ on dipstick, indicating intense pyuria from either cystitis or pyelonephritis
B
WBC casts in urine microscopy, formed when tubular inflammatory exudate is incorporated into Tamm-Horsfall protein matrix within renal tubules
✓
C
Isomorphic RBCs (15/hpf) and blood 2+ on dipstick, indicating mucosal bleeding from bladder cystitis
D
Granular casts (2-5/hpf), indicating tubular injury and therefore upper urinary tract infection
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A 48-year-old woman presents with a 3-week history of progressive fatigue, weight gain of 5 kg, cold intolerance, and constipation. On examination, she has bradycardia (52 bpm), delayed deep tendon reflexes, periorbital puffiness, and a non-tender diffuse goitre. TFTs: TSH 68 mIU/L (reference 0.4-4.0), free T4 5.1 pmol/L (reference 9-25 pmol/L), free T3 2.3 pmol/L (reference 3.5-7.8 pmol/L). Anti-TPO antibodies are 840 IU/mL (reference <35). Which mechanism BEST explains why TSH is disproportionately elevated relative to the modest fall in free T4?
A
The pituitary secretes TSH in response to direct neural signals from the hypothalamus; declining T4 has no direct feedback effect on TSH-secreting thyrotrophs
B
TSH secretion follows an inverse log-linear relationship with free T4; a small decline in free T4 from its set point causes an exponentially large rise in TSH, explaining why TSH becomes markedly elevated before free T4 falls below the reference range
✓
C
Anti-TPO antibodies directly stimulate TSH receptors on thyrotrophs, producing TSH independent of T4 levels (analogous to TSH receptor antibodies in Graves disease)
D
Chronic hypothyroidism causes pituitary thyrotroph hypertrophy, which non-specifically increases TSH output regardless of T4 levels — a purely anatomical phenomenon
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A 65-year-old man presents with worsening renal function (creatinine rising from 1.1 to 3.2 mg/dL over 4 weeks), oliguria, and bilateral leg swelling. He reports taking high-dose ibuprofen for knee pain for 6 weeks. His urine microscopy shows: 20-30 WBCs/hpf (predominantly eosinophils on Hansel stain), WBC casts, few granular casts. No RBC casts. Urine eosinophilia is confirmed (>1% of urinary WBCs are eosinophils). Which pathological process and mechanism BEST explains his acute kidney injury?
A
NSAID-induced acute tubular necrosis from direct mitochondrial toxicity in proximal tubular cells, causing isomorphic cell death without immune activation
B
NSAID-induced acute interstitial nephritis (AIN): hapten–drug conjugate triggers delayed-type (Type IV) hypersensitivity response in the renal interstitium; CD4+ T cells and macrophages infiltrate, producing interstitial oedema, tubulitis, and eosinophilic infiltrate
✓
C
NSAID-induced pre-renal AKI from prostaglandin inhibition reducing renal afferent arteriolar vasodilation; eosinophiluria reflects eosinophil degranulation in the glomerulus
D
NSAID-induced renal papillary necrosis from direct ischaemia of the papilla; eosinophiluria indicates tissue sloughing of necrotic papillary epithelium mixed with eosinophils
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A 38-year-old man with known alcohol use disorder (30-40 units/week for 12 years) presents with jaundice (total bilirubin 85 µmol/L), tender hepatomegaly, fever (38.5°C), and mild ascites. LFTs: ALT 62 IU/L (reference <40), AST 195 IU/L (reference <40), ALP 112 IU/L, GGT 420 IU/L (reference <50), albumin 26 g/L, INR 1.8. Serum ammonia is 95 µmol/L. Which finding in this LFT panel is MOST diagnostically specific for alcoholic liver disease (rather than viral hepatitis of comparable severity)?
A
Elevated GGT (420 IU/L), which is a non-specific enzyme inducible by many drugs and is not specific to alcohol
B
AST:ALT ratio of 195:62 ≈ 3:1 (>2:1), which reflects the combined effect of alcohol-induced mitochondrial AST release and alcohol suppression of hepatic pyridoxal phosphate (vitamin B6) — a cofactor preferentially required by ALT
✓
C
Hypoalbuminaemia (26 g/L) and elevated INR, which are specific to alcoholic liver disease and do not occur in acute viral hepatitis
D
Elevated serum ammonia (95 µmol/L), which is a specific marker of alcoholic hepatitis distinguishing it from viral hepatitis
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A 29-year-old man and his partner have been trying to conceive for 20 months. Semen analysis (WHO 2021): ejaculate volume 2.1 mL; sperm concentration 14 × 10⁶/mL (reference ≥16 × 10⁶/mL); total sperm count 30 × 10⁶/ejaculate; total motility 38% (reference ≥42%); progressive motility 24% (reference ≥30%); normal morphology (Kruger strict criteria) 3% (reference ≥4%). His FSH is mildly elevated (9.2 IU/L, reference 1.5-12.4 IU/L). Which statement BEST characterises his semen analysis findings and the significance of the mildly elevated FSH?
A
He has azoospermia (no sperm in ejaculate); the elevated FSH indicates primary testicular failure and the only option is donor sperm
B
He has oligoasthenoteratozoospermia (OAT syndrome) — reduced sperm concentration, reduced motility, and abnormal morphology; mildly elevated FSH suggests impaired spermatogenesis with partial Sertoli cell feedback failure, but does not distinguish obstructive from non-obstructive azoospermia and is consistent with moderate primary testicular dysfunction
✓
C
He meets all WHO 2021 reference limits except total motility (38% vs reference ≥42%); this isolated asthenozoospermia is the only abnormality, and FSH is irrelevant to semen analysis interpretation
D
His sperm concentration (14 × 10⁶/mL) is normal by WHO 2021 criteria; the only abnormality is morphology (3%), making this isolated teratozoospermia; FSH elevation confirms a Sertoli-only pattern
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A 55-year-old woman presents with a 2-month history of worsening right upper quadrant pain. Investigations: total bilirubin 22 µmol/L (CB 6, UCB 16), ALT 38 IU/L (normal), AST 42 IU/L (normal), ALP 88 IU/L (normal), GGT 45 IU/L (normal), albumin 42 g/L (normal), INR 1.0 (normal), haemoglobin 9.8 g/dL (MCV 74 fL), reticulocyte count 8.2%, LDH 680 IU/L (elevated), haptoglobin undetectable. Peripheral blood film: polychromasia, spherocytes, and fragmented red cells. DAT (Coombs) test is positive (IgG only). Which pattern of bilirubin abnormality is MOST consistent with this presentation, and what is the diagnosis?
A
Conjugated (direct) hyperbilirubinaemia from intrahepatic cholestasis; the normal ALP argues against cholestasis but haemolysis can cause canalicular secretory failure
B
Unconjugated (indirect) hyperbilirubinaemia from extravascular haemolysis exceeding hepatic conjugation capacity; positive DAT confirms autoimmune haemolytic anaemia (AIHA) as the cause; liver enzymes are normal because hepatocytes are intrinsically normal
✓
C
Mixed hyperbilirubinaemia from hepatocellular disease; DAT positivity indicates concurrent autoimmune hepatitis causing haemolysis and hepatocyte injury
D
Unconjugated hyperbilirubinaemia from Gilbert syndrome; the elevated LDH, reticulocytosis, and DAT positivity are unrelated coincidental findings
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A 72-year-old woman with known CKD stage 4 (baseline creatinine 280 µmol/L) presents to the emergency department with sudden-onset right loin pain radiating to the groin. Urine microscopy shows: pH 5.0, specific gravity 1.028, 60 RBCs/hpf (isomorphic), leucocyte esterase negative, nitrite negative, and hexagonal crystal-shaped structures with a faint yellowish hue. No casts. Urine sodium excretion fraction (FeNa) is 0.8%. CT KUB shows a 7 mm hyperechoic foci in the right ureter. Which crystal type, stone composition, and patient risk factor BEST align with this finding?
A
Calcium oxalate crystals (envelope-shaped); radiopaque on plain X-ray; associated with hypercalciuria and hyperoxaluria; most common stone type in CKD
B
Cystine crystals (hexagonal, yellowish); formed in persistently acidic urine from impaired tubular reabsorption of cystine, ornithine, lysine, and arginine (COLA) due to autosomal recessive cystinuria; radiolucent but faintly opaque on CT
✓
C
Struvite (magnesium ammonium phosphate) crystals ('coffin-lid' shaped); formed in alkaline urine (pH >7.2) from urease-producing organisms; require active infection (positive nitrite and LE)
D
Uric acid crystals (rhomboid or rosette-shaped); radiolucent on plain X-ray; form in acidic urine in patients with gout or CKD with uric acid overproduction
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A 28-year-old woman presents with 5 days of fever, severe headache, and photophobia. She returned from a rural area 2 weeks ago. Lumbar puncture yields crystal-clear CSF under elevated opening pressure (280 mmH₂O). CSF analysis: WBC 280/mm³ (92% lymphocytes, 8% neutrophils), protein 95 mg/dL, glucose 28 mg/dL (simultaneous blood glucose 95 mg/dL; CSF:blood glucose ratio = 0.29). Gram stain is negative. AFB stain is negative. India ink is negative. VDRL is negative. Which diagnosis BEST fits this CSF pattern, and which SINGLE additional test would provide the MOST rapid and specific confirmation?
A
Bacterial meningitis (pyogenic); polymorphonuclear predominance and very low CSF glucose are the key features — a lymphocytic CSF with 280 cells excludes bacterial meningitis
B
Tuberculous meningitis; lymphocytic pleocytosis with moderately low CSF glucose and elevated protein in a patient from a rural endemic area are characteristic; most rapid confirmatory test is CSF adenosine deaminase (ADA) activity assay
✓
C
Viral (aseptic) meningitis; lymphocytic CSF with low glucose is classic for viral meningitis; HSV PCR is the most specific confirmatory test
D
Cryptococcal meningitis; India ink negative result excludes Cryptococcus; no further workup is needed; diagnosis is viral meningitis by exclusion
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A 45-year-old man with acute lymphoblastic leukaemia (ALL) develops confusion, oliguria, and severe muscle cramps 48 hours after starting induction chemotherapy. Labs: creatinine 4.2 mg/dL (rapid rise from baseline 0.9), uric acid 18 mg/dL, potassium 6.8 mEq/L, phosphate 9.2 mg/dL, calcium 6.8 mg/dL, LDH 4,800 IU/L. Urine microscopy shows amorphous, brick-red crystalline precipitates and multiple casts. Which urinary finding MOST specifically points to the mechanism of AKI in this patient?
A
Muddy-brown granular casts, indicating acute tubular necrosis from nephrotoxic chemotherapy agents causing proximal tubular cell death
B
Amorphous uric acid crystals (brick-red/orange precipitates) in acidic urine, representing tubular precipitation of massive uric acid released from lysed leukaemic cells — obstructing tubule lumen and causing oliguric AKI (tumour lysis syndrome)
✓
C
Calcium phosphate crystals (amorphous, precipitating in alkaline urine) from hypercalcaemia of malignancy causing nephrocalcinosis and renal failure
D
RBC casts from leukaemic glomerular infiltration causing glomerulonephritis and obstructive AKI from renal parenchymal destruction
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