Home
| Lab / Clinical Finding | Diagnosis / Disease |
|---|---|
| Genetic, Metabolic, and Immune | |
| Colonies of Pseudomonas in lungs, Cl⁻ on sweat test, immunoreactive trypsinogen | Cystic fibrosis (CFTR gene mutation; fat-soluble vitamin deficiency) |
| ↑ AFP on second trimester screening | Down syndrome, Edwards syndrome |
| ↑ β-hCG, ↓ PAPP-A on first trimester screening | Down syndrome |
| ↑ Homocysteine and methylmalonic acid, ↓ folate | Vitamin B12 deficiency |
| Anti-histone | Drug-induced lupus |
| ↓ T cells, ↓ PTH, ↓ Ca²⁺, absent thymic shadow on CXR | Thymic aplasia (22q11 deletion: DiGeorge syndrome) |
| Recurrent infections, eczema, thrombocytopenia, ↑ IgE and IgA, ↓/n IgG and IgM | Wiskott-Aldrich syndrome (WAS gene mutation) |
| Infectious Diseases | |
| Bacteria-covered vaginal epithelial cells, ⊕ whiff test | “Clue cells” (Gardnerella vaginalis) |
| Ring-enhancing brain lesion on CT/MRI in AIDS | Toxoplasma gondii (multiple), CNS lymphoma (may be solitary) |
| Dilated cardiomyopathy with apical atrophy, megacolon, megaesophagus | Chagas disease (Trypanosoma cruzi) |
| Atypical lymphocytes, heterophile | Infectious mononucleosis (EBV infection) |
| Narrowing of upper trachea and subglottis (Steeple sign) on x-ray | Croup (parainfluenza virus) |
| Cytoplasmic inclusions in Purkinje cells of cerebellum and in hippocampal neurons | Negri bodies (rabies) |
| Cardiovascular | |
| Concentrically laminated calcified spherules (psammoma bodies) | Papillary thyroid carcinoma, somatostatinoma, meningioma, mesothelioma, ovarian serous papillary cystadenocarcinoma, prolactinoma |
| Boot-shaped heart on x-ray | Tetralogy of Fallot (due to RVH) |
| Rib notching (inferior surface, on x-ray) | Coarctation of the aorta |
| Delta wave and shortened PR interval on ECG; may lead to supraventricular tachycardia | Wolff-Parkinson-White syndrome (bundle of Kent bypasses AV node) |
| Electrical alternans (alternating amplitude of R waves on ECG) |
Cardiac tamponade |
| Granuloma with giant cells after pharyngeal infection | Aschoff bodies (rheumatic fever) |
| ↑ fibrin degradation products (D-dimer) | DVT, DIC |
| Empty-appearing nuclei with central clearing in thyroid cells | papillary thyroid carcinoma (“Orphan Annie” eyes) |
| “Brown” tumor of bone | Hyperparathyroidism or Osteitis fibrosa cystica |
| Hypertension, hypokalemia, metabolic alkalosis, ↑ aldosterone, ↓ renin | 1° hyperaldosteronism (e.g. Conn syndrome) |
| 🍽️ GI & Hepatic | |
| Mucin-filled cell with peripheral nucleus | “Signet ring” cells (diffuse gastric carcinoma) |
| Anti-transglutaminase/anti-deamidated gliadin/anti-endomysial | Celiac disease (diarrhea, weight loss) |
| Narrowing of bowel lumen on small bowel follow-through | “String sign” (Crohn disease) |
| “Lead pipe” appearance of colon on imaging | Ulcerative colitis (loss of haustra) |
| Thousands of polyps on colonoscopy after puberty | Familial adenomatous polyposis (APC mutation) |
| “Apple core” lesion on barium enema x-ray | Colorectal cancer (usually left-sided) |
| “Nutmeg” (mottled) appearance of liver | Chronic passive congestion (RHF, Budd-Chiari) |
| Eosinophilic cytoplasmic inclusion in hepatocytes | Mallory body (alcoholic hepatitis) |
| Fatty infiltration of hepatocytes, cellular “ballooning”, eventual necrosis | Fatty liver disease (alcohol use or metabolic syndrome) |
| Anti-smooth muscle antibodies (ASMAs), anti-LKM1 | Autoimmune hepatitis |
| Antimitochondrial antibodies (AMAs) | Primary biliary cholangitis (female, cholestasis, portal hypertension) |
| Low serum ceruloplasmin | Wilson disease |
| Migratory thrombophlebitis (migrating DVTs and vasculitis) | Trousseau syndrome (pancreatic adenocarcinoma) |
| Hematology & Oncology | |
| RBC Basophilic stipplings | Sideroblastic anemia, Thalassemias |
| Howell-Jolly bodies | Post-splenectomy or nonfunctional spleen |
| Hypochromic, microcytic anemia | Iron deficiency, lead poisoning, thalassemia, sideroblastic anemia |
| “Hair on end” (crew cut) appearance on skull x-ray | β-thalassemia, sickle cell anemia (marrow expansion) |
| Hypersegmented neutrophils | Megaloblastic anemia (B12 or folate deficiency) |
| Anti-GpIIb/IIIa | Immune thrombocytopenia |
| “Owl’s eye” giant B cells | Reed-Sternberg cells (Hodgkin lymphoma) |
| “Starry sky” pattern with tingible body macrophages | Burkitt lymphoma (t[8:14], c-myc, EBV) |
| Lytic (“punched-out”) bone lesions on x-ray | Multiple myeloma |
| Monoclonal spike on serum protein electrophoresis | Multiple myeloma, Waldenström macroglobulinemia, MGUS |
| Stacks of RBCs | Rouleaux formation (↑ ESR, multiple myeloma) |
| Auer rods in myeloblasts | Acute promyelocytic leukemia (APL) |
| “Smudge” cells | Chronic lymphocytic leukemia (CLL) |
| MSK & Rheumatology | |
| “Tennis racket”-shaped cytoplasmic organelles | Langerhans cell histiocytosis (Birbeck granules) |
| “Soap bubble” lesion in femur/tibia on x-ray | Giant cell tumor of bone |
| “Codman triangle” or sunburst pattern on x-ray | Osteosarcoma |
| “Onion skin” periosteal reaction | Ewing sarcoma |
| Anti-cyclic citrullinated peptide and rheumatoid factor | Rheumatoid arthritis |
| Needle-shaped, negatively birefringent crystals | Gout (monosodium urate) |
| ↑ uric acid | Gout, Lesch-Nyhan, tumor lysis syndrome, diuretics |
| Rhomboid, positively birefringent crystals | Pseudogout (calcium pyrophosphate) |
| “Bamboo spine” on x-ray | Ankylosing spondylitis (HLA-B27) |
| Skin & Autoimmune | |
| Antinuclear, anti-dsDNA, anti-Smith, antiphospholipid | Systemic lupus erythematosus (SLE) |
| ANCA (p-ANCA/MPO and c-ANCA/PR3) | Microscopic polyangiitis, EGPA, GPA, PSC |
| Anti-Scl-70 (topoisomerase I), anti-RNA polymerase III | Diffuse scleroderma |
| Anti-centromere | Limited scleroderma (CREST) |
| Anti-desmoglein | Pemphigus vulgaris |
| Anti-hemidesmosome | Bullous pemphigoid |
| Keratin pearls on skin biopsy | Squamous cell carcinoma |
| Neuro & Psychiatry | |
| High AFP in maternal serum | Dating error, Open neural tube defects |
| Bloody or yellow CSF on lumbar puncture | Xanthochromia (subarachnoid hemorrhage) |
| Loss of dopaminergic neurons in substantia nigra | Parkinson disease |
| Intracellular eosinophilic inclusion in neuron | Lewy body (Parkinson, Lewy body dementia) |
| Extracellular amyloid in gray matter of brain | Senile plaques (Alzheimer disease) |
| Hyperphosphorylated tau in neurons | Neurofibrillary tangles (Alzheimer, Pick bodies) |
| “Pseudopalisading” pleomorphic brain tumor cells | Glioblastoma |
| Small blue cells around central neuropil | Homer-Wright rosettes (neuroblastoma, medulloblastoma) |
| Renal & GU | |
| RBC casts in urine | Glomerulonephritis, hypertensive emergency |
| WBC casts in urine | Acute pyelonephritis, transplant rejection |
| Granular “muddy brown” casts in urine | Acute tubular necrosis |
| Waxy casts with low urine flow | End-stage renal disease |
| “Lumpy-bumpy” glomeruli on IF | Infection-related glomerulonephritis (IgG, IgM, C3) |
| Linear IgG deposits on glomerular/alveolar BM | Goodpasture syndrome |
| Necrotizing vasculitis (lungs) + glomerulonephritis | GPA (c-ANCA), Goodpasture syndrome |
| Cellular crescents in Bowman's space | Rapidly progressive glomerulonephritis |
| “Wire loop” glomerular capillaries on LM | Diffuse proliferative glomerulonephritis (SLE) |
| “Tram-track” appearance of capillary loops | Membranoproliferative glomerulonephritis |
| Effacement of podocyte foot processes on EM | Minimal change disease, FSGS (more common in Black patients) |
| “Spike and dome” subepithelial deposits | Membranous nephropathy |
| Eosinophilic nodular glomerulosclerosis | Kimmelstiel-Wilson lesions (diabetic nephropathy) |
| Thyroid-like appearance of kidney | Chronic pyelonephritis |
| Repro & Endocrine | |
| ↑ hCG | Multifetal gestation, molar pregnancy, choriocarcinoma, dysgerminoma, Down syndrome |
| Koilocytes (raisinoid nuclei, perinuclear halo) | HPV infection (risk for cervical cancer) |
| “Fried egg” cells, ↑ hCG, ↑ LDH | Dysgerminoma |
| Schiller-Duval bodies, ↑ AFP | Yolk sac tumor |
| Call-Exner bodies (granulosa cells around eosinophilic fluid) | Granulosa cell tumor (ovary) |
| “Chocolate cyst” in ovary | Endometriosis |
| “Blue domed” breast cysts | Fibrocystic change |
| Reinke crystals (eosinophilic inclusions in Leydig cells) | Leydig cell tumor |
| Lines of Zahn (thrombus with alternating layers) | Arterial thrombus (pre-mortem) |
| 🌬️ Pulmonary | |
| Charcot-Leyden crystals (eosinophilic, hexagonal) | Asthma |
| Curschmann spirals (whorled mucus plugs) | Asthma |
| “Honeycomb” lung appearance on CT/CXR | Idiopathic pulmonary fibrosis |
| Golden-brown dumbbell-shaped (fusiform) rods in alveoli (Prussian blue stain) | Asbestos (ferruginous) bodies |
| Apical lung mass with Horner syndrome | Pancoast tumor (superior sulcus tumor) |