Malignant Fibrous Histiocytoma Arising From Discoid Lupus Erythematosus

Abstract

While the association of discoid lupus erythematosus (DLE) and subsequent squamous cell carcinoma is well known, there are no reports in the English-language literature concerning the association of DLE and soft-tissue sarcoma. We describe a patient with DLE and malignant fibrous histiocytoma.

Atypical Fibroxanthoma Arising in a Scar of Discoid Lupus Erythematosus

“…6 In our opinion, these findings, in association with the lack of a complete immunohistochemical evaluation, do not allow us to exclude an AFX, which is the most likely diagnosis because the key histologic indicators for MFH, including deep invasion (deep subcutis/fascia), necrosis, and perineural/perivascular invasion, 7 were not present. 6 The exact etiology of the development of malignancies in DLE scars is still not completely clear, but several hypotheses have been suggested. With regard to epithelial tumors, the most widespread theory emphasizes that UV light exposure plays a primary causal role, compounded by the decrease in protective melanin in DLE with hypopigmentation.…”

“…4,5 Instead, the onset of soft tissue sarcomas in a DLE scar is a very rare event because only one case of ''malignant fibrous histiocytoma'' (MFH) has been described in the literature. 6 Regarding this last report, dating back to 1988, the authors described a dermal lesion mainly consisting of a dense infiltrate of spindle cells with moderate pleomorphism and a high mitotic rate that showed no stain for cytokeratin or epithelial membrane antigens by the immunoperoxidase method. 6 In our opinion, these findings, in association with the lack of a complete immunohistochemical evaluation, do not allow us to exclude an AFX, which is the most likely diagnosis because the key histologic indicators for MFH, including deep invasion (deep subcutis/fascia), necrosis, and perineural/perivascular invasion, 7 were not present.…”

“…6 Regarding this last report, dating back to 1988, the authors described a dermal lesion mainly consisting of a dense infiltrate of spindle cells with moderate pleomorphism and a high mitotic rate that showed no stain for cytokeratin or epithelial membrane antigens by the immunoperoxidase method. 6 In our opinion, these findings, in association with the lack of a complete immunohistochemical evaluation, do not allow us to exclude an AFX, which is the most likely diagnosis because the key histologic indicators for MFH, including deep invasion (deep subcutis/fascia), necrosis, and perineural/perivascular invasion, 7 were not present. 6 The exact etiology of the development of malignancies in DLE scars is still not completely clear, but several hypotheses have been suggested.…”

“…8 This, together with chronic inflammation per se, has also been considered a possible causal factor for the development of soft tissue sarcomas from DLE, by unknown mechanisms. 6 In general, scars of various origin are common vulnerable areas for the subsequent development of cutaneous tumors, including AFX, 10,11 and according to recent studies, such an event would be due to the interruption of the normal innervation and lymphatic network occurring in scarring sites, with a consequent imbalance of lymphatic circulation and release of neuromediators. 12 These changes would lead to an alteration of local cutaneous immunity, which would favor hyperreactivity and, consequently, immune disorders or immunosuppression that would facilitate the onset of skin infections or cancer.…”