Cutaneous multiple myeloma (MM) is a rare disease. It can be primary or secondary in origin. The secondary type is further classified into specific and nonspecific types. The specific type is uncommon and is known as a secondary cutaneous plasmacytoma. We report a case of secondary cutaneous plasmacytoma in a 58-year-old man who had a history of plasma cell tumour of the lung and multiple myeloma. He achieved complete remission after the completion of chemotherapy and autologous stem cell transplant (ASCT). However, five months later, he developed multiple erythematous nodules on the whole body. Skin biopsy revealed diffuse neoplastic cells infiltrate in the reticular dermis with sparing of the upper papillary dermis and epidermis. The neoplastic cells were monotonous and homogenous with variable degrees of cytological atypia. Occasional cells showed distinctive plasma cell features. Plasma cell lineage was confirmed with CD138. The cells were immunoreactive to Kappa. Ki-67 was greater than 90%. They were non-immunoreactive to CD45, CD3, CD20, CD79 alpha and CK AE1/AE3. The findings were consistent with secondary cutaneous plasmacytoma. Our case illustrates that MM may present with nonspecific dermatological manifestations. As specific cutaneous involvement of MM is very uncommon; a high degree of clinical suspicion, detailed medical history and histopathological examination are required to arrive at an early diagnosis.
Solitary extramedullary plasmacytomas are rare, discrete mass of neoplastic monoclonal plasma cells in the soft tissue with no evidence of multiple myeloma. They constitute 3 % of all plasma cell tumors and less than 1 % of head and neck malignancies. A 43 year old lady presented to our clinic with complains of diplopia and headache for 4 weeks. Computed Tomography scan showed a mass lesion in the sphenoid sinus eroding the sinus floor, right wall, basisphenoid and parasellar area. A biopsy of the mass reported as plasmacytoma. Systemic examination revealed no evidence of dissemination of the disease confirming the diagnosis of a solitary extramedullary plasmacytoma. The patient was subjected to 25 fractions of radiotherapy. Here, we report a rare case of solitary extramedullary plasmacytoma of the sphenoid sinus.