What are the signs and symptoms of pleomorphic sarcoma (malignant fibrous histiocytoma) of soft tissue?

Updated: Nov 07, 2018
  • Author: Gregory Scott Stacy, MD; Chief Editor: Felix S Chew, MD, MBA, MEd  more...
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The most common clinical presentation is an enlarging painless soft-tissue mass in the thigh, typically 5-10 cm in diameter. The majority of tumors are intramuscular. At gross pathologic examination, the lesion is multilobulated, with necrosis, degeneration, or hemorrhage on the cut surface. In some tumors, extensive hemorrhage can be present. Although the border of the tumor may appear well defined at gross pathologic examination, microscopic spread along muscle fibers and fascial planes is often present. Microscopically, tumor cells with variably pleomorphic nuclei are characteristic. There is no characteristic immunohistochemical profile. Immunohistochemical analysis is used to help exclude other tumors that may have a pleomorphic appearance. [1]

Rare signs and symptoms include episodic hypoglycemia and rapid tumor enlargement during pregnancy. Additionally, UPS has been associated with hematopoietic diseases such as non-Hodgkin lymphoma, Hodgkin lymphoma, multiple myeloma, and malignant histiocytosis.

Retroperitoneal tumors may present with constitutional symptoms, including fever, malaise, and weight loss. The tumor is often large at presentation and may cause displacement of the bowel, kidney, ureter, and/or bladder.

UPS may also occur secondary to radiation exposure and shrapnel injury and may be seen adjacent to metallic fixation devices, including total joint prostheses. Early and complete surgical removal using wide or radical resection is indicated because of the aggressive nature of the tumor.

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