Week 4: Neoplasms of kidney, urinary tract, and prostate Flashcards
Angiomyolipoms
- most clinically significant benign tumor of kidney, hamartomatous
- associated with tuberous sclerosis
- sporadic: unilateral, solitary, seen in middle aged women
- well circumscribed, usually in renal cortex
- diagnosed on CT scan
- has mature fat, abnormal blood vessels, and spindle cell proliferation that resembles smooth muscle
- can bleed
Oncocytoma
- benign epithelial tumor
- micro:composed of large cells with small uniform nuclei and abundant eosinophilic cytoplasm
- solid enhancing mass, usually found incidentally
- indistinguishable from RCC
- gross: encapsulated, mahogany brown, central stellate scar
- no yellow, necrosis, hemorrhage
Incidence and epidemiology of renal cell carcinoma
-most common malignant parenchymal tumor in adult kidney
-30,000 cases/year in US
-95% sporadic: risk factors are smoking, obesity, uncontrolled HTN
5% familial: assoc with Von Hippel-Lindau disease. inactivation of VHL gene on chrom 3 (tumor suppressor gene)
Types of renal cell carcinoma
- clear cell carcinoma (75%)
- chromophil papillary type- 15%
- chromophobe type -5%
- collecting duct- 1%
Work up of a renal mass.
- IVP (not really used) or renal ultrasound
- CT scan with contrast required
- chest x-ray and bone scan to look for metastatic disease
- usually DON’t biopsy the lesion
Clinical presentation of renal cell carcinoma
- Classic triad: hematuria, flank plain, mass (however, all three rarely found together in patients
- have vague non specific abdominal plain, GI complaints, weight loss
- paraneoplastic syndromes (e.g. release of renin, EPO, PTHrP, ACTH)–>polycythemia, hypercalcemia, Cushing, hepatic dysfunction, HTN, anemia, fever
Spread of renal cell carcinoma
- 30% are metastatic at initial presentation
- spread through lymphatics, port system, blood, direct extension
- propensity to grow into renal vein and vena cava as a tumor thrombus
- distant metastasis to lung, bones, brain, adrenal, liver,
Gross pathology of renal cell carcinoma (renal adenocarcinoma)
- all types look similar at gross level
- usually solitary and unilateral
- von Hippel Lindau: multiple and bilateral
- occur in cortex, large, round, commonly with fibrous capsule
- variegated appearance with cut surface having yellow, brown, white and gray areas
- hemorrhage necrosis, and fibrosis are common
Microscopic features of clear cell carcinoma
- 75% of all renal carcinomas
- large cells with clear cytoplasm arranged in solid nests or alveolar structures, separated by prominent vascular network
- divided into 4 grades
1. large cells, uniform nuclei, 2. larger nuclei 3. large, pleomorphic nuclei, prominent nucleoli, 4. lose architectural features, more spindle shaped and pleomorphic. resembles sarcoma.
Microscopic features of papillary carcinoma
- papillary and tubular growth pattern, smaller cells without clear cytoplasm
- well differentiated and low grade
- high grades uncommon
- mutation of MET gene localized in chromosome 7
Staging of renal cell carcinoma
-best prognostic indicator
T1: limited to kidney, 7mm
T3: into major veins: I or peripnephric invasion
T4: invasion to adrenal or into surround structures
N1-1: nodal metastases
M1: distant metastates
Treatment of renal cell carcinoma
- only curative treatment is surgery
- chemo and radiation not effective
- immunotherapy such as Il-2 or INF used for metastatic disease
- anti VEGF type agents
Incidence of Wilm’s Tumor
- most common tumor of kidney in childhood
- ages 2-10 yo
Clinical presentation of Wilm’s Tumor
- usually presents as palpable mass
- can cause hematuria, pain, failure to thrive
- often unilateral
- sensitive to chemo and radiation
- increased risk if associated with WAGR syndrome: predisposed to Wilm’s, Aniridia, genitourinary abnormalities, retardation
- associated with WT-1 mutations, Beckwith Weidaman
Gross pathology of Wilm’s Tumor
-well delineated, globular, large, grayish white, with pressure atrophy of surround kidney
Microscopic features of Wilm’s Tumor
- blastema (embryonic cells), primitive glomerular tubules, stroma cells
- small ovoid cells with hyper chromatic nuclei and scant cytoplasm
- necrosis and high mitotic rate in anapestic tumors
- grades I: well differentiated, II: intermediate-primitive tubules, III: undifferentiated, resembles undiff. nephroblast
Treatment of Wilm’s Tumors
- combo treatments: nephrectomy, chemotherapy, radiation
- stage, grade, cell type are predictors
- high survival rate
Incidence and etiology of urothelial carcinoma
- can occur anywhere from renal calyces to urethra
- mostly in bladder
- risk factors: cigarette smoke, Schistosomiasis, azo dyes, l
Symptoms of urothelial carcinoma.
- gross or microscopic hematuria that is PAINLESS
- painless hematuria in patient >40 yo. think Bladder Cancer
- occasionally with dysuria or frequency/urgency
Histological features of urothelial carcinoma.
- usually transitional cell carcinomas
- Two types: papillary or flat
- normal urothelium is 7 layers thick or less
1. Low grade: includes papiloma, grade I and II: papillary structures linked with thickened transitional epithelial cells. Normal to moderate cytologic abnormalities
2. High grade: includes grade III, carcinoma in situ, and some grade II. Associated with loss of heterozygocity and mutations in p53 tumor suppressor gene mutations. CIS are flat lesions
Behavior and treatment of urothelial carcinoma
- low grade -80% are superficial and low grade
- tends to recur
- multifocal
- invasion and metastasis uncommon
rx: surgical resection - high grade
- invade early through BM into lamina propia and into muscle wall
- metastasize
rx: radical cystectomy
Incidence of adenocarcinoma of the prostate. Diagnosed how?
- most common cancer in men
- 30% of patients over 70 have occult prostate cancers at autopsy
- diagnosed by transrectal biopsy of the prostate. Multiple biopsies taken by needle from different areas of the prostate
Symptoms of prostate carcinoma
- most have no symptoms, detected as elevation of serum PSA level or nodule on examination
- symptoms late in course of cancer: obstructive voiding complaints, back pain, bone pain (metastases)
histological features of prostate carcinoma
- small irregular infiltrative glands (normal prostate has large glands with two layer epithelium-basal cells)
- single layer of enlarged cells
- no basal cells; k903 negative (normal prostate has basal cells positive for k903 and p63)
- large nuclei with prominent nucleoli
- perineural invasion
- luminal crystals mucin
- express new antigens- racemase
Prognosis and treatment of prostate cancer.
- low grade localized prostate cancer is often cured with treatment. May take up to 20 years to cause symptoms or spread
- high grade cancers with bone metastases have poor prognosis
- hormone therapy is cornerstone of treating advanced disease, i.e. blocking testosterone
