Benign fibrous histiocytomas are among the most common soft tissue tumors and are made up of a mixture of fibroblasts, histiocytes, and chronic inflammatory cells. These are commonly found in skin and less commonly in deep soft tissues. There are reports of the presence of a malignant counterpart of fibrous histiocytoma in the breast; however, existence of benign fibrous histiocytoma in breast is a very rare occurrence.
We present here a case of benign fibrous histiocytoma at an uncommon location with a common presentation. This is a case of 45-year-old female patient, who complained of a painless focal area of hardness and itching in the left areolar region that developed gradually for 1 year, with recent onset of areolar skin thickening, erythema, and mastalgia on the left side. Physical examination revealed a focal area of nodular thickening in the areolar region on the left side with erythema and skin excoriation. No mass was palpable in either breast or axilla. A subsequent mammogram showed an area of focal thickening in the areolar region. Ultrasound also showed a similar finding of nodular skin thickening. Paget’s disease was suspected based on clinical and imaging findings. The contralateral breast was normal. Afterward, a core needle biopsy was done, but the histopathology report was inconclusive and showed only a spindle cell lesion. In due course, excisional biopsy was performed and on the basis of morphology and immune-histochemical markers, a diagnosis of benign fibrous histiocytoma was made.
Benign fibrous histiocytomas are varying soft tissue tumors that show wide variations in anatomic locations, biologic behavior, and pathologic features. Its diagnosis can be very challenging by imaging and even on histopathology. It must be based on the combination of morphological features and immunohistochemistry. Breast is an extremely uncommon location, and its presentation can mimic invasive carcinomas. A number of other benign and malignant skin lesions may be considered as probable differential diagnosis. It is worthwhile to keep these diverse entities in mind as differential diagnosis, with regards to this particular clinical presentation, which can be beneficial in dealing with challenging cases.