Pregnancy-Associated Giant Paraspinal Desmoid-Type Fibromatosis Managed with Function-Preserving Resection

Background: Desmoid-type fibromatosis is a rare, locally aggressive fibroblastic neoplasm that does not metastasize but may cause considerable morbidity through infiltrative growth. Pregnancy-associated giant extra-abdominal paraspinal lesions are uncommon. Main objective of the study is to share our experience of Giant Paraspinal Desmoid-Type Fibromatosis managed with Function-Preserving Resection. A 26-year-old para 1 woman noticed a painless mass over the right upper back of chest during pregnancy 30 months ago. At that time, it measured approximately 4 cm and mass enlarged rapidly after delivery. Later it triggered back discomfort which was impairing daily activities. Examination shown a firm, immobile, and non-tender posterior thoracic mass measuring about 30 × 40 cm. Magnetic resonance imaging demonstrated a giant heterogeneous soft-tissue mass involving the posterior thoracic and paraspinal musculature which was closely related to the spine. A core-needle biopsy showed a benign spindle-cell neoplasm. Function-preserving surgical excision was performed. The morphological and immunohistochemical findings supported desmoid-type fibromatosis. Giant pregnancy-associated paraspinal desmoid-type fibromatosis is uncommon and presents difficult surgical decisions. In anatomically complex disease, preservation of function may appropriately take precedence over microscopic margin clearance.

Keywords: Desmoid-type fibromatosis; aggressive fibromatosis; pregnancy; paraspinal tumor; function-preserving surgery; case report.