[Early IgM decrease in the serum of carcinoma patients with paraneoplastic skin manifestations]

The authors describe two patients suffering from cancer accompanied with paraneoplastic skin disorders (bullous pemphigoid, dermatomyositis). Before the diagnosis of stomach cancer was obtained by X-ray examination, the IgM-level was found lower than in normal persons. The value of the IgM-estimation in the serum seems to be high in the diagnosis of tumours. Other causes of the decreased IgM-level than tumours and paraneoplastic disorders of the skin were not found.