Merkel-cell carcinoma of the upper limb
A 63-year-old woman presented to vascular clinic with a large, painless, exophytic erythematous and centrally indurated lesion of the left arm. Having grown rapidly over the preceding few months and due to recurrent episodes of bleeding, it was investigated in the community by ultrasound. Due to sonographic features of hypervascularity it was presumed to be a haemangioma and referred onto our service.

Her past medical history was significant for hypertension, being an ex-smoker, chronic obstructive pulmonary disease (COPD) and cancer of the left breast that had been treated with wide-local excision, axillary lymph node clearance and chemotherapy 6 years prior to this presentation.

Physical examination revealed a 12 cm × 10 cm fungating soft tissue mass with no evidence of axillary or cervical lymphadenopathy. Following urgent magnetic resonance imaging of the lesion, biopsies were obtained under local anaesthesia. Histology result identified an ulcerated and invasive tumour involving the dermis.

It was composed of sheets of monotonous atypical round cells with hyperchromatic nuclei. The tumour cells were positive for chromogranin, CD56 and CK20 and negative for S-100, TTF-1, LCA and Melan-A.

These confirmed the diagnosis of MCC and the patient was thus treated with wide-local excision and radiotherapy. Further review at 6 months confirms the patient has had a good postoperative course and is free of local recurrence and distal metastases.

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