Plexiform Fibromyxoma.

Context.—: Plexiform fibromyxomas are uncommon gastrointestinal neoplasms that have histologic and molecular features that overlap with other gastrointestinal mesenchymal tumors and present a diagnostic challenge for surgical pathologists.

Objective.—: To provide a review of the clinicopathologic, morphologic, immunohistochemical, and molecular features of plexiform fibromyxomas, with a brief discussion of key features that aid in differential diagnosis.

Data sources.—: Analysis of the pertinent literature (PubMed) and clinical practice experience based on institutional and consultation materials.

Conclusions.—: Plexiform fibromyxoma is a rare benign gastrointestinal mesenchymal tumor. Diagnosis is primarily based on morphology, immunohistochemistry, and the exclusion of other gastrointestinal mesenchymal tumors from the differential diagnosis.