Classic Labs/Findings 5

Question 1

Psammoma bodies?

Answer 1

Meningiomas, papillary thyroid carcinoma, mesothelioma, papillary serous carcinoma of the endometrium and ovary

Question 2

Pseudopalisading tumor cells on brain biopsy?

Answer 2

Glioblastoma multiforme

Question 3

RBC casts in urine?

Answer 3

Acute glomerulonephritis

Question 4

Rectangular, crystal-like, cytoplasmic inclusions in Leydig cells?

Answer 4

Reinke crystals (Leydig cell tumor)

Question 5

Renal epithelial casts in urine?

Answer 5

Acute toxic/viral nephrosis

Question 6

Rhomboid crystals, positively birefringent?

Answer 6

Pseudogout (calcium pyrophosphate dihydrate crystals)

Question 7

Rib notching?

Answer 7

Coarctation of aorta

Question 8

Ring-enhancing brain lesion in AIDS?

Answer 8

Toxoplasma gondii, CNS lymphoma

Question 9

Sheets of medium-sized lymphoid cells with scattered pale, tingible body-laden macrophages (“starry sky” histo)?

Answer 9

Burkitt’s lymphoma (t[8;14] c-myc activation, assoc with EBV; “black sky” made up of malignant cells)

Question 10

Silver-staining spherical aggregation of tau proteins in neurons?

Answer 10

Pick bodies (Pick’s dz: progressive dementia, changes in personality)

Question 11

“Soap bubble” in femur or tibia on x-ray?

Answer 11

Giant cell tumor of bone (generally benign)

Question 12

“Spikes” on BM, “dome like” subepithelial deposits?

Answer 12

Membranous glomerulonephritis (may progress to nephrotic syndrome)

Question 13

Stacks of RBCs?

Answer 13

Rouleaux formation (high ESR, plasma cell myeloma)

Question 14

Stippled vaginal epithelial cells?

Answer 14

“Clue cells” (Gardnerella vaginalis)

Question 15

“Tennis racket” shaped cytoplasmic organelles (EM) in Langerhans cells?

Answer 15

Birbeck granules (Langerhans cell histiocytosis or histiocytosis X: eosinophilic granuloma)

Question 16

Thrombi made of white/red layers?

Answer 16

Lines of Zahn (arterial thrombus, layers of platelets/RBCs)

Question 17

“Thumb sign” on lateral x-ray?

Answer 17

Epiglottitis (H. influenzae)

Question 18

Thyroid-like appearance of kidney?

Answer 18

Chronic bacterial pyelonephritis

Question 19

Tram-track appearance of capillary loops of glomerular BM on light microscopy?

Answer 19

Memrabnoproliferative glomerulonephriitis

Question 20

Triglyceride accumulation in liver cell vacuoles?

Answer 20

Fatty liver dz (alcoholic or metabolic syndrome)

Question 21

“Waxy” casts with very low urine flow?

Answer 21

Chronic end-stage renal dz

Question 22

WBC casts in urine?

Answer 22

Acute pyelonephritis

Question 23

WBCs that look “smudged”?

Answer 23

CLL (almost always B-cell)

Question 24

“Wire loop” glomerular capillary appearance on light microscopy?

Answer 24

Lupus nephropathy

Question 25

Yellowish CSF?

Answer 25

Xanthochromia (e.g. due to subarachnoid hemorrhage)