2019-42 / DECEMBER 9

A 55-year-old male with paratesticular mass with clinical suspicious of an epididymal tumor. Intra-operative frozen section was requested due to ultrasound finding of hypervascularity. A 3.8 cm tumor was received with grossly multilobular appearance. Cut surface showed multilobular lesion with fibrous septae and myxoid/edematous areas.


1. What is the correct diagnosis?

a. Well differentiated liposarcoma – sclerosing /inflammatory subtype

b. Fibrous pseudotumor associated with IgG4 disease

c. Fibromatosis

d. Myxoid liposarcoma

e. Low grade dedifferentiated liposarcoma

1.  a

1. Well differentiated liposarcoma – sclerosing /inflammatory subtype

Sclerosing and inflammatory liposarcomas are rare variants of well differentiated liposarcoma, and occur almost exclusively in the retroperitonium and the paratestis. This particular case had frequent floret giant cells which along with other morphologic findings are very reminiscent of spindle cell / pleomorphic lipoma. This diagnosis of benign disease, however, should be avoided in paratesticular and retroperitonenal locations. Well differentiated liposarcomas have virtually no risk of metastatic behavior but the disease may be difficult to control locally due to high incidence of recurrence. The preferred treatment is with radical orchiectomy and wide local excision of the surrounding soft tissue.
Presence of dedifferentiation (especially high-grade) in liposarcoma is associated with a more aggressive behavior and a metastatic potential. In contrast to the pictures shown, dedifferentiated liposarcoma typically shows biphasic morphology with spindle cells and discrete/separated areas of adipocytic lipoma-like liposarcoma. The spindle cells areas lack the atypical adipocytes and lipoblasts seen in the current case.

Thway K. Well-differentiated liposarcoma and dedifferentiated liposarcoma: An updated review.
Semin Diagn Pathol. 2019 Mar;36(2):112-121.

Fletcher CDM, Bridge JA, Hogendoorn PCW, Mertens F. WHO Classification of Tumours of Soft Tissue and Bone. International Agency of Research on Cancer, 4th edition, 2013.

Daniel Athanazio
Federal University of Bahia, Brazil


Paratestis, liposarcoma, sclerosing