MUC4-Positive Fibroblastoma: Clinicopathological and Molecular Analysis of 7 Cases - PubMed
3 days ago
- #APC mutations
- #MUC4-positive fibroblastoma
- #soft tissue pathology
- Seven cases of MUC4-positive fibroblastoma were analyzed, proposing it as a novel soft tissue tumor entity.
- Tumors occurred in female patients aged 14-60, located in various sites (neck, temple, arm, chest wall, pharynx, thigh), mostly deep-seated, with no recurrences after surgical removal during follow-ups of 2-113 months.
- Histopathological features included well-circumscribed, hypocellular fibrous tissue with nonatypical spindle cells, absence of myxoid stroma, thin-walled patent vessels, extremely long vessels, mast cells, and fat entrapment/overgrowth.
- All tumors tested positive for MUC4 and nuclear β-catenin expression via immunohistochemistry.
- Molecular analysis showed absence of FUS/EWSR1 fusions (common in LGFMS/SEF), APC alterations (inactivating mutations or copy number loss) in all tested cases, and distinct DNA methylation profiles not matching LGFMS or SEF.
- The study supports distinguishing MUC4-positive fibroblastoma from low-grade fibromyxoid sarcoma (LGFMS), sclerosing epithelioid fibrosarcoma (SEF), desmoid fibromatosis, and other fibrous/fibroadipose tumors.