[Hypernephroma and associated AL-amyloidosis with polyneuropathy in monoclonal gammopathy]

Malignant neoplasms may have secondary (reactive, AA), amyloidosis as a sequel. Among carcinomas, this is most frequent with hypernephroma. We report a 60-year-old male patient with progressive polyneuropathy and monoclonal gammopathy of the kappa type. A renal tumor was histologically diagnosed as hypernephroma at nephrectomy. The patient did not improve postoperatively and died three and a half months later from pulmonary embolism. Autopsy revealed a systemic amyloidosis, predominantly with prominent deposits in peripheral nerves. Immunohistochemical staining demonstrated the amyloidosis as of the primary (AL) type, rather than of the expected AA type. A plasmocytoma was not detected, either clinically or at autopsy. We assume here a coincidental rather than causal connection between the hypernephroma and the monoclonal gammopathy with AL amyloid and the neuropathy.