Desmoplastic small round cell tumour of unknown primary origin with lymph node and lung metastases: histological, cytological, ultrastructural, cytogenetic and molecular findings

Abstract

Desmoplastic small round cell tumour (DSRCT) is an extremely aggressive neoplasm belonging to the family of "small round blue cell tumours", which includes primitive neuroectodermal tumour (PNET), Wilms' tumour and Ewing's sarcoma. DSRCT is considered to be a neoplasm derived from a primitive cell. It is immunohistochemically reactive with epithelial, neuronal and mesenchymal cell markers, demonstrating divergent differentiation along three cell lines. Originally thought to arise from serosal surfaces, the tumour has recently been reported in the central nervous system and ovary. The tumour in this case is a neoplasm that meets the histological, immunohistochemical, cytological and cytogenetic criteria of DSRCT; it is not associated with serosal membranes, and it has supraclavicular and axillary lymph node deposits and multiple pulmonary and brain metastases. Tumour cells from our case show cytogenetic similarities with Ewing's sarcoma and PNET. Electron microscopic findings suggest similarities between DSRCT and Wilms' tumour. Cloning and sequencing of PCR products showed in-frame fusion of EWS exon 7 to WT1 exon 8.

Ovarian involvement of a desmoplastic small round cell tumor of unknown primary origin with lymph node and lung metastases: A case report

“…DSCRT is very uncommon and only 15 cases in the English literature were reported until now (2)(3)(4)(5)(6)(7)(8)(9)(10). The DSRCT primarily affects children and young adults, particularly young men, with a reported male to female ratio of 4:1 (11). The initial presenting symptoms are associated with the tumor involvement, such as pain and abdominal distention, however, the majority of the patients present with widespread intra-abdominal and pelvic involvement when first examined.…”

Primary Intraspinal Primitive Neuroectodermal Tumor (PNET): A Rare Occurrence

“…In 1983, Rorke & Becker [7,8] independently reviewed this concept and published separate articles advocating that all central nervous system tumors predominantly composed of primitive neuroepithelial cells be called PNETs. It has been postulated that PNETs arise from neoplastic transformation of primitive neuroepithelial cells in subependymal zones.…”

Desmoplastic small round cell tumor of the central nervous system: report of two cases and review of the literature

“…More recently, even a large cell variant was described [33]. Globular, paranuclear accumulation of intermediate filaments, the basis of the paranuclear dot-like pattern of desmin immunoreactivity, which is a conspicuous ultrastructural feature, are not of themselves diagnostic of DSRCT [4,34,35].…”