Author(s)

Corriero A, Armillotta N, Caramella D, Viacava P, Naccarato G.
Ospedali riuniti s.Chiara - Radiodiagnostica 56100 - Pisa / ITALY

Patient

male, 77 year(s)

Patient was admitted to the hospital because of gross hematuria, debility, left flank pain with a big mass.

Patient was admitted to the hospital because of gross haematuria during the last few days, debility, abdominal pain and a large mass on the left flank. Laboratory test were normal apart decrease of HCT, RBC, HBG, and increase of creatinina. Urinary bladder mapping was negative and urinary cytology obtained was positive for transitional cell carcinoma. Intravenous urography (IVU) reveals a parenchymal mass in the lower two-thirds of the left kidney without opacification of lower chalices and limited opacification in middle chalices. Expansion of upper chalices. Regular parenchyma and collecting system of right kidney (Fig. 1). Longitudinal sonogram throughout the left kidney reveals an ill-defined hypoechoic mass in the lower pole, with solid and dilated aspect of lower chalices (Fig.2). Axial contrast-enhanced CT scan doesn’t allow to clearly recognize the left lower chalices. The renal pelvis is constricted and encircled by solid tissue. The perirenal fat tissue is infiltrated and the anterior renal fascia is thickened (Fig.3). The patient was submitted to left nephro-ureterectomy. Histopatological diagnosis was: collecting duct carcinoma (Fig.4).

Collecting duct carcinoma (CDCs) is a rare tumor arising from the medullary region of the kidney and is also named “Bellini duct carcinoma”. This tumor constitutes less than 1 percent of malignant epithelial renal neoplasm in adult population. There are just over 100 cases reported in literature, with a male predominance (2:1), the age at diagnosis is 55 years, although the age range is wide, with cases reported in children as young as 13 years old and adult over 80 years of age [1]. In the WHO classification, the tumor is grouped with RCC (Renal Cell Cancer). An origin from the collecting ducts has been established. The CDC includes at least three different clinico-pathological entities: 1) the classically described tubulo-papillary type with stromal desmoplasia; 2) lower grade, often cystic tumors; and 3) neoplasm with possible derivation from the loop of Henle [2]. Usually located in the central region of the kidney, the tumor tends to distort adjacent calyces and the renal pelvis. Areas of necrosis and satellite nodules may be present, often displaying infiltration of perirenal and renal sinus fat. Some tumours grow as masses within the renal pelvis. Sometimes gross renal vein invasion is seen. The diagnosis is difficult and to some extent is one of exclusion. While most collecting duct carcinomas are located centrally in the medullary zone, other common forms of renal cell carcinoma (papillary, clear cell) may also arise centrally from cortical tissue of the columns of Bertin. The sarcomatoid change is a pattern of dedifferentiation that other types of renal carcinoma, the cytoplasm is generally eosinophilic and glycogen is usually inconspicuous. Criteria for diagnosis CDC have been proposed. Major criteria includes: location in a medullary pyramid; typical histology with irregular tubular architecture and high nuclear grade; inflammatory desmoplstic stroma with numerous granulocytes; reactive with antibodies to high molecular weight cytokeratin; reactive with Ulex europaeus agglutinin lectin; absence of urothelial carcinoma. Minor criteria includes: central location; papillary architecture with wide, fibrous stalks and desmoplastic stroma; extensive renal, extrarenal and lymphatic and venous infiltration; intra tubular epithelial atypia adjacent to the tumor. The main differential diagnoses of CDC include: papillary renal cell carcinoma, adenocarcinoma or urothelial cell carcinoma with glandular differentiation arising in renal pelvis and metastatic adenocarcinoma. A recent study in Japan has demonstrated the mode of presentation was classified as symptomatic in 65.4% of cases (abdominal pain, flak mass, and hematuria), incidental in 24.7% and not available in 9.9%. Regional lymph node metastasis was histologically detected in 44.2% of patient, while 32.1% of the population had distant metastasis at presentation: lymph node, lung, liver, bone (often osteoblastic) and adrenal gland are common [3].