Light chain restriction analysis of bone marrow plasma cells in patients with MGUS or 'solitary' plasmacytoma: diagnostic value and correlation with clinical course

A Clinicopathologic Study of Solitary Myeloma

A retrospective clinicopathologic review of 17 solitary myelomas (SMs) including 13 osseous (solitary plasmacytomas of bone [SPB]) and four extraosseous (extramedullary plasmacytomas [EMP]) tumors in 14 male and three female patients was undertaken. The average age of patients with SPB and EMP was 47.2 years and 48.75 years, respectively, and the most common site was the spine and the head and neck, respectively. The possible utility of histologic and cytologic characteristics of the tumor cells to predict evolution to multiple myeloma (MM) was studied. Follow-up was 63 months (SPB) and 107 months (EMP). No consistent cytohistologic features emerged in patients ultimately evolving either into MM (three patients) or developing recurrences (two patients). Thus, although the correct recognition of SM, as distinct from MM, has clinical relevance, morphology does not help further prognostication.

Solitary plasmacytoma of bone and extramedullary plasmacytoma

A small proportion of patients with plasma cell myeloma have a solitary plasmacytoma of bone. Strict staging criteria, including normal MR imaging studies of the axial skeleton and the long bones and absence of monoclonal plasma cells detected by flow cytometry or PCR, are required for diagnosis. Radiotherapy at a dose of 4500 cGy is required to eradicate the local tumor. Many patients enjoy prolonged disease-free survival, but the incidence of systemic relapse is high. It is expected, however, that if strict diagnostic criteria are applied some patients may be cured. Extramedullary plasmacytoma is an even rarer plasma cell disease which usually occurs in the head and neck area. Careful microscopic and immunohistochemical studies are required for the correct diagnosis, because this disease can be confused with other malignancies, particularly lymphomas. The treatment of choice is radiotherapy which, in cases of head and neck plasmacytomas, should encompass the adjacent lymph nodes. Most patients with extramedullary plasmacytoma can be cured, and fewer than 30% develop a distant failure in the form of multiple myeloma or multiple extramedullary tumors.

Solitary plasmacytoma of bone: clinical features, treatment and survival

Eleven patients with solitary plasmacytoma of bone were seen between 1978 and 1991. A retrospective review of the clinical features, treatment and survival of these patients was made with the aim of helping to define those at risk for early development of myeloma. Nine patients (82 per cent) had paraparoteinemia at diagnosis. Treatment consisted of local irradiation plus or minus surgery (nine patients) and surgery alone (two patients). No patient received adjuvant chemotherapy. One patient had evidence of both generalized osteopenia and immunoparesis, and progressed to myeloma within six months. Four patients (36 per cent) progressed to myeloma. All of these had paraprotein levels which continued to rise following initial treatment. Three patients died of myeloma at 12, 81 and 144 months and the other patient is alive with myeloma at 76 months. Patients without paraproteinemia at presentation or whose paraprotein decreased after treatment did not progress to myeloma. Three patients have been followed for 8, 11 and 19 years with no evidence of myeloma. Failure of paraprotein to clear after local treatment suggests occult disseminated disease and is predictive of later development of overt myeloma.