Unusual cutaneous lesions associated with chronic myelomonocytic leukaemia

A 69-year-old man presented with unusual nodular cutaneous lesions of 3 years duration predominantly involving the chest, upper back and scalp. Histopathological changes in biopsy specimens from affected skin resembled those seen with granuloma annulare even though there was a lack of epithelioid cells. Based on the sluggish course of the condition, leukocytosis with monocytosis in peripheral blood and the findings on electron microscopic examination of peripheral blood cells, he was diagnosed as having chronic myelomonocytic leukaemia (CMMoL). At lower magnification under the electron microscope, the nodular skin lesions showed pleomorphic cell features with monocytes and histiocytic cells of abnormal appearance. The skin lesions were thus considered to be an unusual type of leukaemia cutis.