Clinical and pathologic cutaneous manifestations of malignant histiocytosis

Abstract

The clinical and pathologic changes in the skin of five patients with malignant histiocytosis were studied. The clinical signs included papules, nodules, noduloulcers and purpura. The histopathologic changes included exocytosis of inflammatory cells, infiltration of the papillary and reticular dermis with neoplastic histiocytes, and periadnexal and perivascular infiltrates. Phagocytosis of RBCs and nuclear debris by atypical histiocytes was seen in two cases. In one case, the skin lesions were the only initial manifestation of the disease. Skin involvement occurs in about 10% to 15% of all cases of malignant histiocytosis. Hence, it is important to include malignant histiocytosis in the differential diagnosis of patients with such skin lesions, especially when clinical symptoms may be suggestive of this disease.

Aggressive histiocytic disorders that can involve the skin

“…There is a deep dermal and/or subcutaneous infiltrate of atypical histiocytes around adnexal structures and blood vessels in MH. 126 The cells show variable pleomorphism with atypical nuclei. Phagocytosis of erythrocytes and nuclear debris (emperipolesis) is found in some cases.…”

“…Phagocytosis of erythrocytes and nuclear debris (emperipolesis) is found in some cases. 126 The malignant histiocytes stain positively with concanavalin-A, a histochemical marker for macrophages/histiocytes. 127 They also express CD25, CD68, Mac-387, 128 and in some cases, they are S-100 protein and/or CD30 positive.…”