Giant periosteal aggressive epithelioid osteoblastoma: 21-year-old male presents case in the midshaft of his femur

Abstract

We report a rare case of giant periosteal osteoblastoma in the femur of a 21-year-old male. The patient presented with a painful, firm, non-tender mass in his left thigh. The pain was worse at night and was temporarily relieved with NSAIDS. He had no fevers, night sweats, or weight loss. The patient underwent preoperative radiological studies including plain radiographs, MRI, bone scan, and CT scan. An open biopsy was subsequently performed that was consistent with an aggressive, epithelioid osteoblastoma. Pathology demonstrated a neoplasm characterized by cohesive sheets of epithelioid osteoblasts, mixed with areas of conventional osteoblastoma displaying prominent osteoblastic rimming of woven bone trabeculae in a fibrovascular stroma. The patient subsequently underwent resection, cryosurgery, fixation, and bone grafting with cortical strut allografts. At final follow-up, 32 months postoperatively, there was no evidence of local recurrence. The patient had resumed all his normal activities. He could run without pain and had no restrictions with activities. The goal of this case report is to aid professionals in the diagnosis and treatment of highly uncommon aggressive osteoblastomas.

Aggressive Osteoblastoma of Temporal Bone Causing Facial Palsy in a 9-year-old Child: A Case Report Based on 2020 WHO Classification of Bone Tumors

“…Epithelioid osteoblasts are round cells with abundant eosinophilic cytoplasm, an eccentric, oval nucleus with prominent nucleoli, and some degree of atypia. 2,3,7,11,14,16,17 Epithelioid osteoblasts are at least twice the size of normal osteoblasts and, frequently, show a large, clear cytoplasmic area with enlarged Golgi apparatus, which displaces the nucleus. 2,3,7,11,14,[16][17][18] Osteoid can be found around individual tumor cells or in broad zones surrounding epithelioid osteoblasts.…”

“…Aggressive osteoblastomas are composed of an irregular network of bone trabeculae distributed in a loose stroma with prominent vasculature. 2,3,7,11,14,16,17 The most important histological finding is the presence of epithelioid osteoblasts that form solid sheets in intertrabecular spaces or rim osteoid trabeculae. Epithelioid osteoblasts are round cells with abundant eosinophilic cytoplasm, an eccentric, oval nucleus with prominent nucleoli, and some degree of atypia.…”

A case of epithelioid osteoblastoma of the thoracic vertebra in a 12-year-old male: a case report and review of literature

“…Osteoblastomas (OBs) account for 1% of all benign bone tumors 1 . Epithelioid osteoblastoma (EO), specifically, is an uncommon and highly aggressive variant of OB, primarily recognized for its tendency to local invasion and a notably elevated recurrence rate.…”

“…Occasionally, it can exhibit a more aggressive local growth pattern, which may lead to cortical destruction and the development of secondary aneurysmal bone cysts. The diagnosis of OB relies on histological findings, specifically the presence of a bone-forming tumor characterized by trabeculae of remodeled woven bone surrounded by well-developed, plump osteoblasts within a vascularized background 1 – 3 , 6 .…”

Epithelioid Osteoblastoma Combined with Aneurysmal Bone Cyst Originating from the Right Temporal Bone and the Greater Wing of the Sphenoid Bone

“…The tumor was considered a chondroblastoma combined with aneurysmal bone cysts, a giant cell tumor of the bone, or osteosarcoma ( Figures 1 , 2 , 3 , 4 , 5 ). 1 , 2 , 3 …”