Fibrosarcoma: a challenging diagnosis

Area of Science:

• Oncology
• Pathology
• Dermatology

Background:

• Fibrosarcomas are rare soft tissue malignancies originating from fibrous connective tissue.
• Subtypes include low-grade fibromyxoid sarcoma (LGFMS) and sclerosing epithelioid fibrosarcoma (SEF).
• Histological overlap between fibrosarcoma subtypes is a known diagnostic challenge.

Observation:

• A 53-year-old patient presented with an axillary tumor initially diagnosed as a solitary fibrous tumor.
• Recurrence and metastases prompted re-evaluation, leading to a differential diagnosis of breast metaplastic carcinoma due to p63 and hormone receptor expression.
• Chemotherapy resistance necessitated further investigation.

Findings:

• Immunohistochemical analysis revealed MUC4 expression and specific morphological features.
• The final diagnosis was a hybrid LGFMS-SEF tumor.
• This case underscores the diagnostic complexities in soft tissue tumors.

Implications:

• Accurate diagnosis of soft tissue tumors requires a comprehensive immunohistochemical panel.
• Clinical course and patient history are crucial for definitive diagnosis.
• Distinguishing between fibrosarcoma subtypes and other malignancies is critical for appropriate treatment and prognosis.