Myeloma of the jaw bones: a clinicopathologic study of 33 cases

A clinicopathologic study of 33 cases of plasma cell neoplasm of the jaw bones was performed.

The Mayo Clinic's pathology files through 1995 were reviewed for cases of plasma cell neoplasia involving the jaw bones. Clinical data, radiologic features, and follow-up data were obtained from the hospitals of origin, referring physicians, and Mayo Clinic files. The histopathologic features of the 33 tumors were studied.

There were 21 (64%) male and 12 (36%) female patients, ranging in age from 25 to 81 years (mean, 57.7 years). Twenty-one tumors (64%) were classified as solitary plasmacytoma of bone (SPB) and 12 (36%) as multiple myeloma (MM). Among the SPB cases, 15 (71%) involved the maxilla, and 14 patients were men, with a mean age of 57.1 years. Abnormal serum protein was found in 22% of patients, and in nine patients (43%) the SPB converted to MM after a median of 20.7 months. Among the MM cases, seven (58%) affected the maxilla, seven patients were men with mean age of 58.3 years, and abnormal serum protein and Bence-Jones protein were found in 42% and 73% of the patients, respectively. Anaplastic histology was identified in seven (33%) SPB and six (50%) MM tumors, and amyloid was present in eight (38%) SPB and three (25%) MM tumors. Twelve (57%) SPB patients died of the disease after a median disease-free survival of 6.75 years, and the overall and disease-free survival rates at 5 and 10 years were 52%, 33%, 33%, and 24%, respectively. All MM patients died of the disease after a median survival of 17.6 months, and the 5-year and 10-year survival rates were 8% and zero. Eighty-six percent of the SPB patients with anaplastic histologic findings died of the disease (average survival, 3.8 years), whereas only 43% of those with classic histologic findings died of the disease (average survival, 11.75 years). Among MM patients, anaplastic histologic findings were associated with a 9-month average survival (26-month average survival for MM patients with classic histologic findings).

SPB patients seem to have a better prognosis than MM patients, and 43% of SPB tumors convert to MM after an average of 20.7 months. Anaplastic histologic findings seem to be associated with lower survival rates and periods for SPB patients and lower survival periods for MM patients.