Tumors of the Urinary Tract

Inflammatory "tumors" of kidney

Renal abscess

rare complication of acute pyelonephritis due to destruction of renal elements and coalescence of small abscesses
may extend through renal capsule to form a perinephric abscess.
Associated with flank pain and fever

Treatment: drainage catheter and antibiotic therapy, is the favored management.

Xanthogranulomatous pyelonephritis

Def: inflamation of the kidney and renal pelvious that has charachteristics of granuloma and xanthoma (multiple golden-yellow nodules, 0.3 to 3.0 cm in diameter caused by abundant lipid laden macrophages)
Can affect any age group, mostly women 30 to 60 yo.
Presents with flank pain, fever, malaise, anorexia, and weight loss. A tender flank mass may be palpable.
2/3 of affected kidneys are nonfunctioning; stones are noted in 20 to 70%. Urine infection is noted in 70%.
Radiologically, it may be impossible to exclude renal neoplasm, therefore many affected kidneys are removed surgically.

Malakoplakia (Robins has this under Cystitis) Doubt we need to know this.

Def: a lesion of U/G tract common in immunosuppressed due to defective macrophage response to coliform bacteria and consisting of soft yellow elevated and friable 3-4 cm mucosal plaques.
More than 50 cases have been reported, bilateral in 25% of cases, 80% affecting women with a mean age of 44 years.
Diffuse multinodular cortical enlargements or cancer-like appearance, with large yellow mass infiltrating perinephric fat.
Abscesses and cystic sytructures may be present. See bladder path for histo

Epithelial renal neoplasms of adulthood – most significant

Benign epithelial neoplasms

Papillary adenoma: Small (5mm or less) epithelial neoplasms with papillary architecture, most often noted in the superficial renal cortex. They are the most common renal epithelial proliferations, far outnumbering RCC, hence they are "statistically benign". Lesions larger than 5 mm should be viewed with suspicion, since they cannot be distinguished from papillary RCC.

Renal oncocytoma: Accounts for 5% of "clinically apparent" renal cell neoplasms.

originates in the collecting duct.
Abundant finely granular eosinophilic cytoplasm in cells arranged in organoid clusters in a fibrous background.
distinguish from chromophobe RCC by lack of mitotic activity, necrosis, papillary architecture, etc. Provided the diagnosis is accurate, the lesion is considered benign.

Malignant Epithelial Neoplasms = Renal cell carcinoma (RCC)

is a family of cancers derived from renal tubular epithelium, frequently from upper pole.
Adults (M:F=2:1) Think male smoker age 50-70.

associated with von Hippel-Lindau disease and deletion on chromosome 3, tuberous sclerosis, autosomal dominant polycystic kidney disease, and acquired renal cystic disease in patients with chronic renal failure

Clinical triad: flank pain, hematuria, and palpable mass.
However, at least 40% of patients have none of these symptoms, and present with systemic endocrine symptoms (hypertension, hypercalcemia, erythrocytosis, gynecomastia) or an assortment of miscellaneous findings (elevated ESR, anemia, fever,, amyloidosis, or hepatic dysfunction).
presents as metastatic carcinoma of unknown primary. widespread use of CT scan and has resulted in the incidental detection of many asymptomatic early stage renal tumors.

Sarcomatoid morphology may be seen in any of the RCC. A separate category of "sarcomatoid carcinoma" is no longer recognized.

Types of Renal Cell Carcinoma:

(1) Clear cell renal cell carcinoma (RCC) is the most common RCC. Deletion of chromosome 3

from proximal tubule epithelium characterized by sheets of clear cells interspersed with a delicate vascular network
Grossly: variegated cut surface; areas of firm yellow tissue interspersed w cysts, hemorrhage and necrosis

(2) Papillary RCC is the second most common RCC.

from the proximal tubule, and genetically shows polysomy
Gross: well circumscribed, with hemorrhage and necrosis which may give a hypovascular appearance radiologically.
characterized morphologically by papillary architecture.
The tumor cells have a variable N/C ratio and may be basophilic or eosinophilic.

Psammoma bodies and abundant foamy macrophages in the cores of papillae are common findings.

(3) Chromophobe RCC: accounts for about 5% of RCC M=W

arises from the collecting duct., (neoplastic spectrum of Renal oncocytoma)

Genetic deletion in 90%. Cytologically distinct from clear cell and papillary
composed of two cell types:

(a) large cells with pale flocculent cytoplasm very prominent cell membranes
(b)smaller cells with finely granular brightly eosinophilic cytoplasm

Gross: solid, well circumscribed and beige or light brown. It is and, and.
carries a better prognosis than other types of RCC.

(4) Collecting duct carcinoma (CDC) (also an RCC)

centered in the renal medulla, with infiltrative border and gray-white cut surface.
composed of irregular ductlike structures, nests and cords set in abundant desmoplastic stroma.
"hobnail" appearance of cells lining duct lumens is often seen.
most ominous prognosis, especially if associated with sickle cell trait called "renal medullary carcinoma".

(5) Neuroendocrine tumors of kidney: Only 6 reported. Includes carcinoid tumor, intrarenal pheochromocytoma, intrarenal neuroblastoma, and renal small cell carcinoma.

(6) Renal cell carcinoma, unclassified: includes any RCC in which sarcomatoid component overgrow original CA

Grading RCC: "Fuhrman grading": based on nuclear characteristics; The grade correlates quite well with survival.

Staging RCC: "Robson system" and TNM system. Features assessed in assigning stage include tumor size, extension into perirenal fat, Gerota's fascia, renal vein or vena cava, regional lymph nodes, adrenal, or adjacent organs, and distant metastases.

Successful treatment of RCC:

radical nephrectomy with individualized inclusion of regional lymph nodes and adrenal gland.
partial nephrectomy, particularly for tumors less than 4 cm in diameter. e.g, unilateral kidney, von Hippel-Lindau syndrome.
RCC has proven stubbornly resistant to radiation therapy, and treatment of disseminated RCC with chemotherapy and/or immunotherapy has shown very limited success. One should note that the clinical course of RCC is notoriously capricious; recurrence 10 years or more after nephrectomy has been documented in 10% of patients who survive that long.

Mesenchymal renal neoplasms of adulthood

Angiomyolipoma: Half the reported cases of this benign tumor have been sporadic, solitary and large; the remainder have been associated with tuberous sclerosis, in which instance they are often small, multiple and bilateral. F>M

Other renal neoplasms of adulthood

Lymphoma quite commonly involves the kidney in patients known to have lymphoma. Large cell lymphoma is the commonest offender.

Metastases to the kidney are surprisingly common (7.2% in a series of over 11,00 autopsies in cancer patients). Lung cancer is the commonest primary site. An interesting piece of trivia is that RCC is the commonest "recipient" of metastatic malignancy from a separate primary.

Renal neoplasms of infancy and childhood

Wilms' tumor (nephroblastoma) >80% of childhood renal tumors. its peak incidence 2-4 yrs of age, rare in adults.

bilateral in 4.4%.. Associated congenital anomalies and malformations are not uncommon.
Presents with palpable abdominal mass in > 90%. Other clinical features may include, pain, anorexia, nausea and vomiting, fever or gross hematuria.
The tumors are usually 5 cm or more in diameter (1/3 are over 10 cm). The cut surface is usually solid/cystic, soft, gray or pink, with areas of hemorrhage and necrosis.
Microscopically, the tumor is composed of variable proportions of blastema, epithelium and
Diagnostic info used for prognistic staging (5 Stages). Prognosis is strongly correlated with the presence or absence of "unfavorable histology" - defined as nuclear anaplasia in blastematous elements.

Mesoblastic nephroma accounts for less than 3% of primary renal tumors in children, and is uncommon after the age of 6 months; however, it is the commonest renal neoplasm in infants in the first three months of age.

Neoplasms of the renal pelvis and ureter and Bladder

Benign epitheleial neoplasms renal pelvis and ureter

Inverted papilloma:

Urothelial papilloma:

Malignant epithelial neoplasms: of the renal pelvis and ureter and Bladder

Urothelial carcinoma: TCC: Transitional Cell Carcinoma of renal pelvis, ureter and Bladder

The renal pelvis and ureter are lined by transitional epithelium; therefore neoplasm = TCC

Risk factors for TCC: advancing age, male gender, tobacco and industrial carcinogen exposure, phenacetin abuse and Balkan nephropathy, and long term treatmeant with cyclophosphamide.

Clinical: Hematuria and flank pain in pevis and ureter but typically painless in the bladder.

multifocal, and about 50% recur. In the ureter, the distal segment is the commonest site of involvement.

Grading TCC (WHO system) depends on assesment architectureal and cytological features: cell polarity and crowding, nuclear size and shape, disposition of nuclear chromatin, the presence or absence of nucleoli and mitotic activity.

Architectural variants: Squamous differentiation (intercellular bridges or keratinization) worsen prognosis.
Glandular differentiation (presence of true glandular spaces within the tumor) worsens response to chemo.

Staging TCC (TNMSystem) is based on level of penetration (lamina propria, superficial or deep muscularis propria, perivesical fat or adjacent organs) , and the presence or absence of nodal or systemic metastases. 75% are low grade and low stage; Invasion into or through the underlying muscle markedly ß survival.

nephroureterectomy with excision of a cuff of bladder mucosa is the operation of choice for these neoplasms.

Gross: papillary soft yellow-brown tumor. masses may be obstructive in the ureter causing hydronephrosis.

Microscopically, the the findings are identical to those noted in TCC of the bladder, including variants which will be described in the section on bladder pathology.

Squamous cell carcinoma comprises a minority of urinary tract neoplasms (renal pelvis, ureter, and bladder), It often arises in a background of chronic infection and/or calculus disease.

5% of North American Bladder cancer; 73% of Bladder CA where schistosomiasis is endemic

Most are of high stage, and survival for 5 years is rare.
Radical surgery is mainstay of therapy.

Adenocarcinoma is rare, mainly occurs in adults, and seems to be associated with chronic infection and/or calculi. Most are of advanced stage, and prognosis is poor. Differential includes metastasis from a distant site, particularly from breast or colon to the ureter.

In Bladder, signet ring type that is urachal has better prognosis than non-urachal.
Surgery is treatment of choice, not responsive to chemo or rads.

Mesenchymal neoplasms (not very significant)

Fibroepithelial polyp affects all age groups (mean 40 years) and is more common in males. It may involve either pelvis or ureter, and commonly obstructs the ureteropelvic junction, causing colicky pain. Grossly, it is polypoid with a stalk. The core consists of loose edematous and vascular stroma, and the surface is covered by benign urothelium.

Leiomyoma, leimyosarcoma, hemangioma and a host of other "pathologic curiosities" have been reported to involve the renal pelvis and ureter. Reference articles are available in the appropriate chapters of the reference texts.