Clear Cell Sarcoma of the Kidney

Abstract

We reviewed 351 cases of clear cell sarcoma of the kidney (CCSK), including 182 cases entered on National Wilms Tumor Study Group (NWTSG) trials 1-4 for which clinical follow-up information was available. Tumors were restaged using NWTS 5 criteria. Mean age at diagnosis in the NWTS group was 36 months with a range of 2 months to 14 years. The male to female ratio was 2:1. Typical gross features included large size (mean diameter 11.3 cm), a mucoid texture, foci of necrosis, and prominent cyst formation. Nine major histologic patterns were identified (classic, myxoid, sclerosing, cellular, epithelioid, palisading, spindle, storiform, and anaplastic); virtually all tumors contained multiple patterns that blended with one another. Immunohistochemical stains were performed on 45 cases; only vimentin was consistently immunoreactive. Consistently negative results with other antibodies helped exclude other tumors in the differential diagnosis; all CCSKs were cytokeratin-negative, including epithelioid tumors that mimicked Wilms tumor, and MIC2-negative, including cellular tumors that mimicked primitive neuroectodermal tumor. The p53 gene product was rarely overexpressed in non-anaplastic CCSKs, but strikingly overexpressed in two of three anaplastic CCSKs. Overall survival was 69%. Multivariate analysis revealed four independent prognostic factors for survival: treatment with doxorubicin, stage, age at diagnosis, and tumor necrosis. Of note, stage 1 patients had a remarkable 98% survival rate. No other histologic or clinical variable independently correlated with survival.

Soft Tissue Tumors of Uncertain Origin

“…For example, round cell sarcomas with a CIC-DUX4 translocation or tumors with loss of INI1 protein expression are now recognized as specific sarcomas or possibly members of families of tumors with the common feature of an aberration in a specific biologic or genetic pathway [213,476,477]. Organ-related sarcomas, such as those in the kidney, heart, thyroid, meninges, brain, and spinal cord, are also better recognized, although they are still poorly understood [478][479][480][481][482][483][484].…”

ecancermedicalscience

“…Clear cell sarcoma of the kidney (CCSK) is a rare renal neoplasm of paediatrics, comprising about 3% of all paediatric renal tumours [1, 2]. Formerly, CCSK was classified as Wilms’ tumour until 1970, when it was defined as a separate and independent entity [3].…”

“…Formerly, CCSK was classified as Wilms’ tumour until 1970, when it was defined as a separate and independent entity [3]. CCSK was initially recognised because of its tendency to metastasise to the bone, leading to its poor prognosis (survival rate <30%), despite currently available chemotherapy regimens and radical surgery [1, 4]. The clinical presentation bears a resemblance to Wilms’ tumour, including abdominal mass, abdominal pain, and gross haematuria.…”

“…The clinical presentation bears a resemblance to Wilms’ tumour, including abdominal mass, abdominal pain, and gross haematuria. CCSK is more common in male individuals and usually occurs as solitary renal mass in two- to three-year-old children [1]. CCSK has a high tendency for developing bone metastasis through its course, and thus it was previously called a ’bone-metastasizing renal tumour of childhood’ [5].…”

“…The skeleton and skull are the most common sites of bone metastases and are associated with poor outcome and high mortality [6]. As these tumours are radiologically indistinguishable from Wilms’ tumour [7] and the prognosis is very poor [1, 4, 6], the clinical entity should be kept in mind, so that the diagnosis and treatment are not postponed. We report a rare case of CCSK presenting at an older age with two metastatic masses in the sternum and frontal bones; the patient had previously undergone nephrectomy following a diagnosis of mesoblastic nephroma.…”