Epithelioid multinodular osteoblastoma: a clinicopathologic analysis of 26 cases.

We describe the clinical, radiologic, and pathologic features of 26 osteoblastomas with a multinodular growth pattern (defined as multiple nidi in a single tumor) and primarily epithelioid-appearing cells. Clinical information and histologic slides for all 26 patients and radiologic studies for 9 were examined. Follow-up information was obtained from medical charts at our institution and from correspondence with pathologists who submitted cases in consultation. Of the 23 patients with osteoblastoma whose sex had been recorded, 18 were male and 5 were female (median age, 17.8 y). The most common site was the jawbones, although long bones were also involved. Radiologic studies suggested a benign lesion in 5 patients, a malignant lesion in 2, and indeterminate features in 2. Histologically, the tumors appeared to be multiple nodules of epithelioid cells, most with a lacy, blue-bone matrix. Frequently, there were sheets of cells with no matrix. Follow-up information was obtained for 14 of the 23 patients. One patient died in an automobile accident; all others were alive as long as 29 years after treatment. Epithelioid osteoblastomas mimic osteosarcoma because of similar cellularity and cytologic features. Although follow-up is limited, we are cautiously optimistic that these are benign lesions.

Sarcomas arising in Paget disease of bone: a clinicopathologic analysis of 70 cases.

CONTEXT: Sarcomatous transformation is a rare complication of Paget disease of bone. Prognosis in patients with other types of sarcomas arising in bone has improved in the last several decades because of therapeutic advances. However, because of the rarity of Paget sarcoma, outcome studies in these patients are limited. OBJECTIVE: To determine whether prognosis for Paget sarcoma has improved. DESIGN: Seventy cases of sarcomas arising in the setting of Paget disease were collected, and the histologic and clinical findings were reviewed. Clinical follow-up was obtained in 67 cases. RESULTS: Sarcoma arising in Paget disease tended to arise in older men (46 men, 24 women; age range, 31-88 years; mean age, 66 years) and predominated in the axial skeleton (n = 37), especially in the pelvis. Thirty-three patients had a clinical history of Paget disease ranging in duration from 16 months to 30 years (mean, 15 years). No significant difference in incidence between monostotic (n = 33) and polyostotic (n = 36) disease was noted. Most tumors were osteosarcomas (88%). All tumors were high grade. Follow-up information was obtained in 67 of 70 cases (range of follow-up, 1-252 months). Survival ranged from 1 month to 20 years, with a 5-year survival rate of 10%. CONCLUSIONS: Prognosis remains poor in patients with Paget sarcoma. There is no significant correlation between the number of bones involved with Paget disease or the duration of disease and development of Paget sarcoma. Poor prognosis in Paget sarcoma is unrelated to site or stage at presentation.