Multiple solitary plasmacytomas: about a case with review of the literature

The solitary plasmocytoma is a rare entity corresponding to a proliferation of monoclonal plasma cells, isolated or accompanied by multiple myeloma, bone or extra-bone seat. The multiple localization of plasmocytomas is even rarer. It represents less than 5% of all plasma cell neoplasias. The diagnosis is based on the discovery of a localized tumor, made up of monoclonal plasma cells cytologically identical to those of multiple myeloma. We report the case of a patient, 63 years old, with no particular pathological history, followed for two swellings of sternal and frontal localization evolving for 4 months and whose anatomopathological study concludes with a plasmocytoma. Biochemical exploration found hypercalcemia associated with a monoclonal peak at protein electrophoresis. The patient was referred to us for a spinal cord invasion. The study of the morphology on a spinal smear revealed the presence of a plasma cell level not exceeding 5% but which were all dystrophic in particular by the presence of a flamed cytoplasm and intra-cytoplasmic vacuoles hence the interest a second sample. The biology laboratory plays a crucial role in the diagnosis and monitoring for possible myeloma transformation. The prognosis is generally favorable but remains conditioned by the risk of progression to multiple myeloma.