Myxoid and Lipomatous Solitary Fibrous Tumor of Soft Tissue: A Case Description

We present a case of a myxoid and lipomatous solitary fibrous tumor that was observed in a 67-year-old man. The tumor, which had a maximum diameter of 10 cm, was located in the soft tissues of the dorsal region and appeared macroscopically well delimited and encapsulated. Upon cutting, a markedly gelatinous internal surface was observed. A microscopic study revealed an intense and diffusely myxoid neoplasia, with small areas of adipose aspect, in which histological (staghorn vessels, perivascular hyalinization, fusiform cells of benign aspect) and immunohistochemical (intensive positivity for CD34, Bcl-2 and Cd99 and negativity for muscle markers) data were consistent with a solitary fibrous tumor were observed. To conclude, the main characteristics of this lesion are discussed, and a differential diagnosis is established with other entities.