Periosteal chondroblastoma of the femoral neck: two cases and a review of the literature.

Chondroblastoma is a rare benign cartilaginous tumor mostly confined to the epiphyses and apophyses. Cases outside the epiphyseal region are exceedingly rare. Extramedullary chondroblastomas are exceptional; to our knowledge, only two cases qualified as "periosteal chondroblastoma" have been described in the literature. We report two cases of metaphyseal periosteal chondroblastoma both located on the inferior surface of the femoral neck. Both cases were paucicellular with an unusual dense sclerotic reaction. The diagnosis of chondroblastoma was supported by the expression of histone 3.3, K36M mutant in tumor cells.

A Rare Case Report of Chondroblastoma Pisiform in Adolescent.

INTRODUCTION: Chondroblastoma is a rare primary benign tumor of bone with male predominance and is typically seen in an epiphyseal location. The pisiform is a carpal bone and chondroblastoma of the pisiform has not been reported in the literature to the best of our knowledge. CASE PRESENTATION: An 18-year-old male presented with painful swelling over his right wrist with restriction of ulnar deviation. Based on magnetic resonance imaging findings, two diagnostic possibilities were entertained, namely, giant cell tumor of bone and chondroblastoma. Wide local excision was performed, and histopathology confirmed the diagnosis of chondroblastoma of the pisiform. After 2 years of follow-up, the patient has gained pain-free wrist movements post excision, and there are no signs of recurrence. The Modified Mayo Wrist Score of 75 (fair) improved to 100 (excellent). CONCLUSION: Surgeon should always keep in mind the possibility of the tumor at the rare site and accurately diagnose the tumor with the help of imaging modalities and biopsy.