Primary dermal pleomorphic liposarcoma: utility of adipophilin and MDM2/CDK4 immunostainings

Abstract

Liposarcoma, usually arises in deep soft tissues and pleomorphic liposarcoma (PL), is the rarest histopathologic variant. However, 15 cases of entirely dermal PL have been reported. We describe a case of a 79-year-old man who developed a rapidly growing nodule on his thorax. Excisional biopsy was performed and immunohistochemical studies were carried. The lesion was a well-circumscribed dermal nodule composed of multivacuolated pleomorphic lipoblasts and atypical mitotic figures. Neoplastic cells expressed CD10 and resulted negative S100 protein, Melan-A, MITF-1, AE1/AE3, CD4, CD68 (PGM1), retinoblastoma gene family protein, pericentrine and lysozyme. Adipophilin stain showed the lipid contents in the cytoplasm of the neoplastic cells. MDM2 and CDK4 resulted both negative. A diagnosis of primary dermal PL was made. This case shows the utility of adipophilin immunostaining to prove the lipid contents in neoplastic cells, which has the advantage of using formalin-fixed paraffin-embedded tissue and making needless frozen sections and ultrastructural studies to show these findings. Negative MDM2/CDK4 staining in our case argues against the possibility of dedifferentiated liposarcoma and further supports the diagnosis of true PL.

Perilipin 1 Expression Differentiates Liposarcoma from Other Types of Soft Tissue Sarcoma

“…In addition, perilipin 5 is also expressed in rhabdomyomatous and leiomyomatous tumors and the respective normal cells. Perilipins 2 and 3, however, are positive in virtually all sarcomas but prominently in high-grade sarcomas, only faintly expressed in welldifferentiated liposarcomas, and negative in lipomas and in WAT (for utility of perilipin 2 in PLS 38 ). Therefore, in our hands, perilipins 2 and 3 are not markers of choice to clearly differentiate well-differentiated liposarcoma from lipoma.…”

Liposarcoma: Advances in Cellular and Molecular Genetics Alterations and Corresponding Clinical Treatment

“…With high local recurrence rate and distant metastasis rate, PLS is more invasive than other types of liposarcoma, and is less sensitive to conventional treatment. Histologically, PLS is composed of many irregular cell groups and abundant isolated, non-adherent cells and has distinct polymorphism and common characteristic sheets of bizarre pleomorphic mono or multivacuolated adipoblasts [33][34][35].…”

Expanding the differential of cutaneous epithelioid tumors: A case of dedifferentiated liposarcoma with epithelioid features involving the skin, with review of the literature

“…A comprehensive review of the literature revealed 159 cases in the dermis and/or subcutis, with only 44 cases mentioning dermal involvement . Superficial liposarcomas have been reported in all four liposarcoma subtypes with PLPS being the most common (n = 95) . DDL and myxoid are relatively uncommon (19 and 17 cases respectively) (Table shows the DDL cases).…”