Table 1.
Clinicopathologic features of two cases of primary malignant melanoma of the breast
| Case 1 | Case 2 | |
|---|---|---|
| Age (yr) | 70 | 30 |
| Sex | Female | Female |
| Location of tumor | Right breast parenchyme | Left breast skin |
| Upper inner quadrant | ||
| Key histologic features | Atypical epithelioid cells | Atypical melanocytes |
| No pigmentation (amelanotic) | Heavy pigmentation | |
| Size of tumor (cm) | 2.1 | 4.5 |
| Depth of invasion (mm) | NA | 2 |
| Sentinel lymph node status | Negative | Positive |
| IHC | ||
| CK | Negative | Negative |
| EMA | Negative | NA |
| Vimentin | Positive | Positive |
| S100 protein | Positive | Positive |
| HMB-45 | Negative | Positive |
| Tyrosinase | Positive | Positive |
| BRAF V600E | Positive | Positive |
| Pathologic diagnosis | PNCMB | PCMB |
NA, not applicable; IHC, immunohistochemistry; CK, cytokeratin; EMA, epithelial membrane antigen; HMB-45, human melanoma black-45; BRAF, rapidly accelerated fibrosarcoma (RAF) kinase-related oncogene homolog B; PNCMB, primary noncutaneous melanoma of the breast; PCMB, primary cutaneous melanoma of the breast.