Extramedullary plasmacytoma is a rare disease, characterized histopathologically by infiltration of plasma cells of different maturities and producing monoclonal immunoglobulin outside the bone marrow. J.R.G., 52 years old, male, sought medical assistance due to amaurosis and blocked eye movements. We performed Magnetic Nuclear Resonance of the skull that showed discrete intermediate signal tissue, next to the optic nerve canal and homolateral superior orbital fissure, with slight extension to the lower orbital fissure, associated with thickening of the corresponding meninges, involving the proximal portion of the optic nerve, measuring 1.3 x 1.1 x 2.5 cm. Non-specific aspect, but suggestive of lymphoproliferative lesion. Right and extraorbital tumor excision was performed, in which it was not possible to completely resect the tumor. The anatomopathological examination of the piece showed a neoplasm of plasma cells (plasmacytoma). The diagnosis is made from the exclusion of Multiple Myeloma. The treatments of choice are radiotherapy, due to the high radiosensitivity in 80–100% of cases, and surgery for localized lesions.

Primary adenocarcinoma of the duodenum is a rare clinical condition, accounting for only 5% of all gastrointestinal neoplasms and 0.5% of all intestinal neoplasms. Nonspecific clinical presentation contributes to the majority of cases being diagnosed in advanced stages. The prognosis is poor, with a median survival of five years, varying from 23% to 57% in patients undergoing curative surgery (cephalic duodenopancreatectomy).