COL1A1-PDGFB Fusion Associated Fibrosarcoma of the Uterine Corpus: A Case Report and Literature Review

Abstract

Uterine collagen type 1 alpha 1 (COL1A1) and platelet-derived growth factor beta chain (PDGFB) fusion associated fibrosarcoma is a recently described entity characterized by a specific translocation t(17;22) (q22;q13) leading to the formation of COL1A1-PDGFB fusion transcripts that are typically associated with dermatofibrosarcoma protuberans. So far, only 4 cases of COL1A1-PDGFB fusion associated fibrosarcoma involving the female reproductive system have been reported in the literature. All cases showed strong diffuse expression of CD34. COL1A1-PDGFB fusion associated fibrosarcomas are aggressive tumors with a propensity for chemotherapy resistance and a poor prognosis. We are reporting the fifth case of a uterine COL1A1-PDGFB fusion associated fibrosarcoma. A 58-yr-old female presented with a large uterine mass with extension into bilateral pelvic sidewalls, mesentery of rectosigmoid colon and the vagina. A hysterectomy, bilateral salpingo-oophorectomy, and tumor debulking procedure was performed. Microscopic evaluation revealed a mitotically active cellular spindle cell neoplasm with focal osteoclast like giant cells, myxoid changes and necrosis. CD34 was diffusely and strongly positive throughout the tumor. Next-generation sequencing showed presence of the COL1A1-PDGFB fusion. The patient was treated with multiple chemotherapy regimens, however, progressed under therapy with worsening symptoms and development of extensive pelvic disease. She died of disease 13 mo after the initial diagnosis. In summary, uterine COL1A1-PDGFB fusion associated fibrosarcomas are rare tumors with aggressive clinical behavior that need to be considered in the differential diagnosis of CD34-positive uterine spindle cell neoplasms. Novel treatment options may include imatinib, a tyrosine kinase inhibitor used for treatment of advanced and unresectable dermatofibrosarcoma protuberans that was given in 1 uterine sarcoma case and showed promising initial response.

Dermatofibrosarcoma protuberans：clinical and pathological analysis of Asian samples from one center experience.

“…One was discovered uterine tumor before the diagnosis of DFSP while 3 cases were diagnosed as uterine tumor in the following period after DFSP surgery. There were several reports about COL1A1-PDGFB fusion in the uterine brosarcoma (23)(24)(25). As one of rare uterine diseases, the COL1A1-PDGFB fusion uterine tumor was seen as a potential biological behavior of DFSP.…”

COL1A1::PDGFB fusion uterine sarcoma with a TERT promoter mutation

“…The tumor location was markedly predisposed to the cervix. 10,13,14 Histologically, most cases showed predominantly storiform and herringbone patterns resembling soft-tissue DFSP, specifically the subtype of FS-DFSP. It should be noted that the current case focally displayed a myxofibrosarcoma-like appearance that was not related to the other seven historical cases.…”

“…Of course, long‐term follow‐up is still needed. The other three patients in the literature died of the disease, which all experienced recurrence, and two developed metastases 10,11,13 . Only one patient with tumor recurrence and metastasis was reported as receiving targeted therapy with imatinib.…”

“…The other three patients in the literature died of the disease, which all experienced recurrence, and two developed metastases. 10,11,13 Only one patient with tumor recurrence and metastasis was reported as receiving targeted therapy with imatinib. The patient had a partial response that was followed by disease progression after 6 months.…”

“…10 To the best of our knowledge, only seven cases of COL1A1::PDGFB fusion uterine sarcomas have been reported to date. [10][11][12][13][14] However, subsequent diagnosis remains a conundrum with limited awareness of the clinicopathologic features and the genomic landscape.…”