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Axillary Metastasis of Malignant Melanoma Mimicking a Breast Carcinoma
Author(s) -
Andea A.,
Satter E.,
McEvoy J.R.,
Williams K.,
Mikhitarian K.,
Metcalf J.
Publication year - 2005
Publication title -
journal of cutaneous pathology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.597
H-Index - 75
eISSN - 1600-0560
pISSN - 0303-6987
DOI - 10.1111/j.0303-6987.2005.0320i.x
Subject(s) - pathology , cytokeratin , immunohistochemistry , medicine , breast carcinoma , breast cancer , melanoma , carcinoma , metastasis , cancer , axillary lymph nodes , lymph node , metastatic carcinoma , vimentin , cancer research
We describe here the case of a female patient with an otherwise classic invasive melanoma of the upper extremity, demonstrating the typical immunohistochemical profile, who presented three years later with massive ipsilateral axillary node metastases. The metastatic tumor had morphologic features similar to the primary melanoma, however at immunohistochemical level the tumor cells not only gained expression of pan‐cytokeratin (AE1/AE3) but also lost expression of all standard melanoma markers (S100, Melan‐A, HMB‐45, MIT‐1, and tyrosinase) thus mimicking a poorly differentiated mammary carcinoma. Additional stains reveal expression of Vimentin, NSE, c‐kit, CD10 and negativity for CK7, CK20, BR2, ER/PR, mucin, and LCA. To rule out a breast carcinoma, real‐time RT‐PCR was performed on a lymph node using six breast cancer‐associated genes (>99% sensitivity), which was also negative. Clinical work‐up of the patient failed to reveal abnormal masses in the breast or elsewhere. The clinical history, histological appearance, immunohistochemical profile (including negative CK7 and positive NSE, c‐kit and CD10) as well as a negative RT‐PCR renders almost null the possibility of a breast carcinoma and supports a diagnostic of melanoma in this case. Cases like ours may be easily misclassified unless a concerted approach is used to reach the correct diagnosis.