Faculty Collaboration Database

Epithelioid osteoblastoma. Clinicopathologic and immunohistochemical study of 17 cases. Hum Pathol 2022 Jul;125:68-78

Date

03/27/2022

Pubmed ID

35337839

DOI

10.1016/j.humpath.2022.03.006

Scopus ID

2-s2.0-85129835662 (requires institutional sign-in at Scopus site)   3 Citations

Abstract

Seventeen cases of epithelioid osteoblastoma were reviewed. The tumors most commonly arose from the vertebrae (7 cases), followed by the mandible (3), sacrum (2), bones of the foot (2), and femur, rib, and scapula (1 each). Patients' ages ranged from 5 to 33 years. The tumors measured from 2.0 to 6.5 cm in the greatest diameter (mean = 4.1 cm) and most patients presented with low-grade pain at the affected site. Imaging studies showed expansile lytic lesions with cortical thickening and a mild rim of sclerosis. Histologically all tumors were characterized by active production of bone with a fibrovascular stroma containing microtrabecular aggregates of bone matrix. The osteoblastic proliferation was atypical and showed enlarged cells with prominent nucleoli and abundant cytoplasm imparting them with a striking epithelioid appearance. Immunohistochemical studies showed variable results that caused difficulties for interpretation; 4 of 12 cases showed strong nuclear positivity for FOS, 2 of 12 cases showed strong diffuse nuclear positivity for FOSB; the remaining cases showed variable, sometimes overlapping patterns, considered to be indeterminate. Ki-67 proliferation marker showed low nuclear positivity (∼2%) in 10 cases and a slight increase (<10%) in two cases. Clinical follow-up was available in 14 patients; one patient experienced a recurrence at six months that was treated with additional curetting; the remainder of the patients were all alive and well without evidence of recurrence from 1 to 22 years (median follow up = 3 years). Epithelioid osteoblastoma is an unusual variant of osteoblastoma that has the potential for simulating a malignancy and does not appear to be associated with a more aggressive behavior.

Author List

Suster D, Mackinnon AC, Jarzembowski JA, Carrera G, Suster S, Klein MJ

Author

Jason A. Jarzembowski MD, PhD Sr Associate Dean, CEO CSG, Professor in the Pathology department at Medical College of Wisconsin

MESH terms used to index this publication - Major topics in bold

Adolescent
Adult
Bone Neoplasms
Child
Child, Preschool
Humans
Osteoblastoma
Young Adult