233. Pathology Renal/Urothelial Tract

Question 1

Benign Renal Neoplasms

• Renal Oncocytoma: gross, histo, prognosis
• Angiomyolipoma: gross, prognosis, variants
• Papillary Adenoma: criteria, gross, prognosis

Answer 1

Renal Oncocytoma

• gross: well-circumscribed, enclosed in renal parenchyma, brown color, +/- central scar
• histo: plump large cells w/ glandular pink appearance (high mito#), large round nuclei with prominent nucleoli, may have nuclear atypia/invasive capsule/perinephric fat but BENIGN
• 100% 5 year survival

Angiomyolipoma

• gross: benign tumor of Vessels, Smooth Muscle (perivascular epithelial cells = PEComa), and Fat
• rarely malignant (increase hemorrhage risk with size)
• variants: one type may predominate (fat, muscle)

Papillary Adenoma

• criteria: <1.5cm size, low nuclear grade
• often occur in damaged kidney (sclerosis, inflammation)
• multiple lesions and growth may lead to RCC

Question 2

Clear Cell RCC

• low grade vs high grade (gross, histo)
• Fuhrman Grading

Answer 2

Low Grade

• gross: bright yellow, richly vascular (hemorrhagic)
• histo: chicken wire vasculature, tumor cells in acini, clear cytoplasm (lipid accumulation) with small nuclei (small N:C ratio)

High Grade

• gross: large size, fat necrosis (white and hemorrhagic areas), invasive (no border b/w tumor and perinephric fat)
• histo: large N:C ratio, pink dense cytoplasm

Grading
G1: no nucleoli
G2: nucleoli on high power
G3: nucleoli on low power
G4: bizzare nuclei +/- sarcomatous transformation (spindle-cell sarcoma)

Question 3

Papillary RCC

• gross
• type 1 vs type 2 vs mixed type

Answer 3

Gross: well-circumscribed red/brown lesion prone to hemorrhage/infarction (if large can cause compressive pain, pressure, hematuria)

Type 1: LOW GRADE - small cells, dense cytoplasm, small nuclei, fibrovascular cores

Type 2: HIGH GRADE - bigger cells, pink cytoplasm, big nuclei, fibrovascular cores

Mixed: express both T1/T2 - behaves like T2

Question 4

Chromophobe RCC: gross, histo

Xp11-Assoc Translocation RCC: prevalance, prognosis, histo

Answer 4

Chromophobe

• gross: well demarcated non-descript color
• histo: vague floculent pale pink cytoplasm (more lysosomes), prominent intracellular borders (plant-like) thickened membrane due to organelle accumulation

Xp-11

• very rare tumor
• poor prognosis: rapidly growing, high stage at dx, does not respond to chemo
• variable histo but PSAMOMMA BODIES!

Question 5

Cystitis

• Chronic Cystitis
• Follicular Cystitis
• Schistosoma Cystitis
• Malakoplakia
• BCG cystitis
• Cystitis Glandularis vs. Cystitis Cystica

Answer 5

Chronic: lympocytic infiltrate (plasma cells, lymphocytes), dilated blood vessels, reactive urothelium w/ lymphocyte invasion

Follicular: long-standing chronic = formation of follicles with germinal centers

Schistosoma: eggs

Malakoplakia: e. coli organisms calcified in macrophages due to phagocytic defect (Mikaelis Guttman Bodies)

BCG cystitis: granulomatous inflammation like TB (tx for CIS bladder cancer)

Cystitis Glandularis: enlargement of von brunn nests to look like cysts

Cystitis Cystica: more dilated and with more fluid

Question 6

Urothelial Carcinoma

• Epi of bladder cancer
• types of UCa (2)
• types of one UCa: papilloma, PUNLMP, Low grade, High grade

Answer 6

Epi: 4th most common in M and 9th leading cause of cancer death in M

UCa: Flat (CIS vs Invasive), Papillary (non-invasive vs. invasive)

Papillary Classification

• papilloma: looks papillary but benign lining
• Papillary Urothelial Neoplasm of Low Malignant Potential: indeterminant finding, dx of exclusion, thick urothelium but low grade non neoplastic nuclei
• Low grade papillary UCa: large nuclei w/ low umbrella cell urothelium, thick urothelium, 2o and 3o branching
• High Grade P-UCa: large dark nuclei (NUCLEAR ATYPIA)

Question 7

UCa

• what is most common site
• what are 3 RF
• what is the histo of UCa - CIS (+ variant)
• what is most common type of bladder cancer
• what is staging of high grade papillary UCa

Answer 7

Most common site: bladder

RF: smoking, schistosoma (egypt), pollution (occupational)

CIS: dark dense nuclei, loose dyscohesive cells (shed in urine, dx in urine cytoscopy)
Variant: Pagetoid spread (fairly benign, scattered cells w/ large nuclei - microscopic spread)

Most common type: Low Grade P-UCa

High Grade P-UCa

• T1: no invasion
• T2: LP invasion
• T3: muscularis propria invasion
• T4: extravesical invasion