Work

Recurrent aneurysmal fibrous histiocytoma of the breast with malignant features: a rare case report

Year: 2026

Type: article

Abstract: Aneurysmal fibrous histiocytoma (AFH) is generally a benign soft tissue tumor that most commonly occurs in the extremities and trunk. However, its primary presentation in the breast is exceedingly rare. Within this exceptionally rare subset, only isolated case reports have described recurrent AFH with malignant features. Here, we present a case of recurrent aneurysmal fibrous histiocytoma with malignant features occurring in the breast. Following recurrence, a 73-year-old female underwent modified radical mastectomy. Based on the histopathological and immunohistochemical evaluation of the resected specimen, combined with imaging findings, a final diagnosis of undifferentiated pleomorphic sarcoma (UPS) was established. The tumor in this case exhibited an immunophenotype positive for CD34, CD63, and CD68, with a Ki-67 index of approximately 30%, and harbored BCOR and ARID1A gene mutations. We discuss the histologic, immunohistochemical, and molecular findings that supported the diagnosis of UPS and consider whether this recurrent tumor represents progression from the earlier AFH.

Source: Frontiers in Oncology

DOI: 10.3389/fonc.2026.1899426

Authors: Kui Xiao, Nianqu Zhang, Qing Li, Qiaoran Liu

Institution: Shandong First Medical University

Language: English

Topic: Sarcoma Diagnosis and Treatment

Subfield: Oncology

Field: Medicine

Domain: Health Sciences

SDG: Good health and well-being

Open Access status: gold

Estimated APC paid: $3,801