Ewing’s sarcoma of the kidney

Abstract

Primitive neuroectodermal tumors (PNETs) are small, round-cell tumors of neural crest origin classically found in the central nervous system (CNS) but more recently characterized in the periphery. Peripherally located PNETs (pPNETs) are members of the Ewing's sarcoma family of tumors (EFTs). Renal localization of pPNETs is very rare, is found in young adults, and is characterized by an aggressive clinical course and poor prognosis. We present the case of a young man with renal pPNET characterized by psuedorosette formation, cluster of differentiation 99 (CD 99+), focally positive for neuron-specific enolase (NSE), with cytogenetic findings of the translocation t(11;22)(q24;q12) and the unique abnormality of trisomy 7. To our knowledge, we report the first case of trisomy 7 and PNET.

Renal Primitive Neuroectodermal Tumors

“…5 Wilms tumor 1 (WT-1), a common marker for Wilms tumor, may also be used to rule against a PNET diagnosis, 3,10 although in rare instances, it may also stain positive in renal PNETs. 4 In one study, Friend leukemia virus integration 1 (FLI-1) demonstrated positive staining in 5 out of 8 cases of renal PNET and 0 out of 10 cases of Wilms tumor, indicating that this marker may aid in differentiating the two as well.…”

“…4,6 Dyspnea and dizziness may also be seen if the tumor features atrial involvement. 13 Laboratory abnormalities that may be seen in renal PNET include elevated lactate dehydrogenase, glutamicoxaloacetic transaminase, glutamic-pyruvic transaminase, and creatinine.…”

“…3 Primitive neuroectodermal tumors may occur both within and outside of the central nervous system. 4 Most commonly, peripheral PNETs are found to arise in the chest wall and paraspinal regions. 5 It is less common, although still possible, to see peripheral PNETs in the genitourinary system, as case reports have documented instances of their occurrence in the uterus, 3 epididymus, 3 and bladder.…”

“…1 Renal PNETs present as very clinically aggressive tumors. 3,4,6,10 Cases of local recurrence and metastasis have been shown to comprise more than 50% of the clinical presentations in this cancer, 5 with the most common sites of metastasis shown to be the lymph nodes, lungs, and liver. 6 In a 2001 review of 25 cases of renal PNET, the mean patient survival was approximately 10 months.…”

“…Additionally, PNETs do not feature cartilaginous or myogenous structures. 10 The most diagnostically useful histologic feature of these tumors is the arrangement of the tumor cells into pseudorosettes, clusters of cells with a neurofibrillary stromal core, which serve to indicate neural differentiation [4][5][6]8 (Figure 2, B). Additionally, tumor cells in renal PNETs may also be arranged into nests, cords, or clusters.…”