Abstract
Phyllodes tumor is a biphasic breast neoplasm composed of epithelial and stromal components. Constituting 25% of all phyllodes tumors, the malignant variant is characterized by atypical stromal component demonstrating stromal cellularity, overgrowth, cytologic atypia, mitotic activity and occasionally, heterologous elements. Lung and bone are common sites of distant metastasis, which is associated with poor prognosis. Cutaneous metastasis from a malignant phyllodes tumor (MPT) is extremely rare and may lead to diagnostic challenges due to histopathologic overlap with other dermal spindle cell tumors. A 56-year-old woman presented with a rapidly growing scalp lesion. Physical examination revealed a 2?1.5 cm ulcerated nodule in the left postauricular area. Biopsy showed a dermal/subcutaneous lesion composed of spindled cells showing nuclear atypia and high mitotic activity in a myxoid background, consistent with a high-grade pleomorphic sarcoma. Review of history revealed that the patient had been previously diagnosed with MPT of right breast, treated with mastectomy and concurrent radiotherapy, six months ago. She also complained of dyspnea and chest wall swelling. CT scan of chest showed multiple pulmonary and pleural lesions, largest measuring 10cm compressing the trachea with right upper lobe of lung collapse, pleural effusion and mediastinal lymphadenopathy. The scalp tumor was histopathologically similar to the stromal component of the patients known MPT and was diagnosed as metastatic MPT. The patient was managed conservatively and eventually developed sepsis and acute renal failure and died two months after diagnosis of scalp metastasis. Cutaneous metastasis from a MPT is very rare and frequently a late event. Thorough examination of history and histopathologic comparison with breast tumor is essential to arrive at the correct and timely diagnosis and ensure optimal patient management.
Financial Disclosure:
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