Neoplasms

Question 1

Renal papillary adenoma

Answer 1

Trisomy 7, 17
• less than 1 cm, greater considered low grade RCC; arise from renal tubular epithelium
Cortical, discrete, yellow gray, may be multiple
Acidophilic cytoplasm
Papillae with complex fromds, psmammoma bodies
Grow as tubules, glands, cords, sheets of cells
Cuboidal to polygonal shape, regular, small, central nuclei, scant cytoplasm, no atypia
Thin fibrovascular cores

Question 2

Renal Angiomyolipoma

Answer 2

AD

TSC1 or TSC2 loss of function – tumor suppressor genes

• Thick-walled blood vessels (ANGIO)
• Smooth muscle (MYO)
• Fat (LIPO)
• Originate from perivascular epitheloid cells
DDx w/ RCC
Occasionally spontaneously rupture → massive hemorrhage and shock

Middle aged, F>M
Strong association with tuberous sclerosis

Lesions in brain, skin, kidney, heart, lungs, eyes

Question 3

Renal Oncocytoma

Answer 3

• Type A Intercalated cells of renal cortical collecting ducts
• Mahogany-brown and well circumscribed – central stellate scar
• Quite large >10-15 cm
• Abundant acidophilic, granular cytoplasm
• Alveolar, nesting, tubular or solid pattern
• Packed with mitochondria, eosinophilic

DDx w/ RCC, esp non-clear cell

Adult onset
Rarely familial (b/l, multicentricity, or oncocytosis)
Rare invasion/mets

Question 4

Renal Cell Carcinoma (RCC) pathogenesis

Answer 4

Most sporadic

4% heredity – AD, younger
-Clear cell carcinoma: VHL tumor suppressor gene: Chr 3p25.3 deletions/ translocations → overexpression of HIF-1 (forms complex with MYC), VEGF, IGF-1

• Papillary carcinoma: AD, Trisomy 7, 16, 17, lost Y (MET proto-oncogene on Chr7- hepatic growth factor)
• Chromophobe Renal Carcinoma: hypodiploidy
• Xp11.2 translocation; TFE 3 transcription factor overexpression – young
• Leiomyomatosis and RCC syndrome: AD; FH gene mutation – fumarate hydratase – cutaneous and uterine leiomyomata, aggressive papillary carcinoma with high mets
• Birt-Hogg-Dube syndrome: AD: BHD mutations – folliculin (Skin, pulmonary, renal tumors)

Question 5

Renal Cell Carcinoma (RCC) pathology

Answer 5

• Arise from renal tubular epithelium (adenocarcinoma)
• One pole of kidney - yellowish
• Clear cell carcinoma: PT, u/l, bright yellow-gray-white, distorted renal outline; non-papillary, clear cytoplasm (some granular), glycogen and lipid accumulation – sporadic 95%; average prognosis
• Papillary carcinoma: DCT, b/l; papillary growth pattern- papillae and foamy macrophages in stalk, psammoma bodies, hemorrhagic – highly vascularized; better prognosis; 10-15%
• Chromophobe Renal Carcinoma: Pale eosinophilic cytoplasm in solid sheets, perinuclear clear halos; concentrate around BV; better prognosis; type B intercalated cells of renal cortex CD; 5%
• Sarcomatoid renal cell carcinoma: spindle cells simulating mesenchymal neoplasm; poor prognosis
• Collecting (Bellini) Duct Carcinoma: medullary location; branching tubules lined by highly atypical cuboidal cells, fibrotic stroma, “hobnail”; poor prognosis
• Medullary carcinoma: sickle cell trait; poor prognosis
• Xp11 translocation carcinoma: clear cytoplasm with papillary architecture

Question 6

Renal Cell Carcinoma (RCC) Clinical Features

Answer 6

Classic triad: hematuria, costovertebral pain, palpable flank mass

Before local S/S: large tumor size, and widespread mets
-weight loss, malaise, weakness, fever

60s-80s; M:F 2:1

Widespread hormonal effects – paraneoplastic:
Polycythemia, hypercalcemia, HTN, hepatic dysfunction, feminization or masculinization, cushing syndrome, eosinophilia, leukemoid reactions, amyloidosis

Risk factors: cigarette smoking, HTN, obesity (women), estrogens, asbestos, chronic renal disease, tuberous sclerosis, acquired cystic disease, heavy metals

Mets: lung, bone, regional LN, liver, adrenal, brain

Spread hematogenously – early invasion of renal v.

Question 7

Urothelial (transitional cell) carcinoma of the kidney

Answer 7

• Arises from urothelium of renal pelvis
• Location related to degree and persistence of hematuria
• Infiltation of wall of pelvis/calyces frequent
• Foci of atypia or CIS in grosly normal urothelium remote from pelvic tumor

Hematuria
Small when discovered, may block urine outflow → palpable hydronephrosis and flank pain

Poor prognosis; 5 yr survival: 50-100% low-grade noninvasive lesion to 10% high-grade infiltrating tumor
Concomitant bladder tumors
Assoc. w/ analgesic and Balkan (tubulointerstial) nephropathy; Lynch syndrome