Giant phyllodes tumor of breast with diffuse myxoid changes mimicking low- grade fibromyxoid sarcoma (LGFMS) - A case report

Abstract

Phyllodes tumors are biphasic tumors consisting of epithelial and stromal components that account for less than 1% of all breast tumors. Phyllodes tumors are rare that behave in an unpredictable manner and can rarely have diffuse myxoid changes without an exaggerated intracanalicular pattern with leaf like fronds and stromal hypercellularity. 50-year old lady with left breast lump, morphologically mimicking low grade fibromyxoid sarcoma was finally diagnosed as recurrent phyllodes tumor (intermediate grade) with extensive myxoid change, based on the previous microscopic finding of phyllodes tumor and excluded diagnosis of low grade fibromyxoid sarcoma by MUC4 stain. Recurrent phyllodes tumor which is a common stromal tumor was diagnosed as LGFMS because of its morphology change resembling, LGFMS which was ruled later out with sensitive and specific marker for LGFMS i.e., MUC4.