Massive desmoplastic fibroblastoma with scapular invasion

Desmoplastic fibroblastoma is a rare benign tumor usually associated with a favorable outcome. The tumor is characterized by fibroblastic cells that are sparsely distributed in a collagenous and fibromyxoid background. The growth of this tumor is generally indolent, and most tumors are small, subcutaneous lesions. They tend to behave in a nonaggressive manner, and several studies have reported no recurrences even after marginal excision. Invasion and destruction of bone are distinctly uncommon features. This article describes an unusual case of desmoplastic fibroblastoma that presented with a massive 23-cm tumor. The tumor was also unique for its infiltration and destruction of the scapula. The aggressive clinical features prompted the original physicians to administer chemotherapy, but the tumor exhibited no response to systemic treatment. The patient eventually underwent limb-sparing surgery at our hospital, which included en bloc resection, complete scapulectomy, and osteoarticular allograft replacement. The invasiveness of the tumor and its large size are distinctly unusual for desmoplastic fibroblastomas. Following surgical excision, the patient has remained continuously disease free for >5 years, which is in keeping with the intrinsically benign nature of the tumor. This case demonstrates that desmoplastic fibroblastoma can occasionally reach an enormous size and may exhibit invasive characteristics, but this does not necessarily portend subsequent recurrence of disease.