[Multivesicular vacuolization in malignant histiocytoma of the skin (author's transl]

A 47-year-old patient developed several rapidly growing tumours in his right leg. Histiologic and electron microscopic examination revealed morphological characteristics suggesting the histiocytic origin of the tumour cells. An important finding was the striking number of pleomorphic membraneous inclusions and large vacuoles containing numerous small vesicles. These cytoplasmic inclusions are interpreted as transformed multivesicular bodies. Their formation may be an expression of an increased and bizarre membraneous activity of a malignant cell race. Radiotherapy resulted in a remarkable rapid and complete remission.