A case of amelanotic spindle-cell melanoma presenting as metastases to breast and axillary lymph node: diagnosis by FNA cytology.
Metastatic neoplasms to the breast are relatively rare. Spindle-cell lesions of the breast are also uncommon. Here we present a case of fine-needle aspiration (FNA) of an amelanotic, spindle-cell melanoma metastatic to the breast and axillary lymph node. The patient was a 47-yr-old female who presented with a right breast mass, left axillary adenopathy, and a pigmented skin lesion on the back. FNA of the right breast and left axilla showed malignant, nonpigmented spindle cells that were weakly positive for HMB-45 on immunocytochemistry. The skin biopsy showed a pigmented malignant melanoma with epithelioid features, and also weak positivity for HMB-45. Although malignant melanoma is one of the more common tumors to metastasize to the breast, this is the first known case that showed exclusive spindle-cell morphology. History and physical examination were crucial in making the correct FNA diagnosis. The cytologic differential diagnosis of spindle-cell tumors of breast and the discordant morphology between the primary and metastatic melanotic lesions observed in this case are discussed.
Kobayashi
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Cytopathology and FNA Services, Los Angeles County and University of Southern California Healthcare Network, Los Angeles 90033, USA. gkobayas@hsc.usc.edu
Cobb
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D001365:Axilla; D014408:Biomarkers, Tumor / Q000032:analysis; D001707:Biopsy, Needle; D001943:Breast Neoplasms / Q000737:chemistry / Q000556:secondary*; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008198:Lymph Nodes / Q000473:pathology*; D008207:Lymphatic Metastasis / Q000473:pathology; D018328:Melanoma, Amelanotic / Q000737:chemistry / Q000556:secondary*; D008875:Middle Aged; D012878:Skin Neoplasms / Q000737:chemistry / Q000473:pathology*
D014408:Biomarkers, Tumor