Immunohistochemical techniques to compare primary vs. metastatic mucinous carcinoma of the skin

J Cutan Pathol. 2010 Apr;37(4):411-5. doi: 10.1111/j.1600-0560.2009.01436.x. Epub 2009 Sep 24.

Abstract

Background: Primary and metastatic mucinous carcinomas in skin are histologically indistinguishable. Immunohistochemical panels help differentiate primary and metastatic adenocarcinoma of skin, but data regarding mucinous carcinoma is scant.

Methods: We stained five primary mucinous carcinomas, two mucinous carcinomas metastatic to skin and five primary breast and colon mucinous carcinomas with p63, CD15, CK5/6, CK7, CK20, calponin and D2-40 to identify patterns that might differentiate primary from metastatic disease. We also searched for myoepithelial cells in all cases.

Results: All cases of primary mucinous carcinoma of the skin were positive for CK7, 40% showed rare cells labeled for p63 and 20% of cases labeled focally for CK5/6. The breast mucinous carcinomas metastatic to the skin were negative for all markers except CK7, although 60% of primary breast carcinomas labeled for p63. Colon mucinous carcinoma labeled only for CK20.

Conclusions: In a small subset of mucinous carcinomas (20% in this series), positive labeling for CK5/6 indicated primary cutaneous tumor. Staining with p63 also favored primary over metastatic disease. Myoepithelial cell layers were not consistently identified to enable the identification of primary disease.

MeSH terms

  • Adenocarcinoma, Mucinous / metabolism*
  • Adenocarcinoma, Mucinous / pathology
  • Adenocarcinoma, Mucinous / secondary
  • Adult
  • Aged
  • Aged, 80 and over
  • Biomarkers, Tumor / metabolism*
  • Breast Neoplasms / pathology
  • Diagnosis, Differential
  • Female
  • Head and Neck Neoplasms / pathology
  • Humans
  • Immunohistochemistry / methods*
  • Male
  • Middle Aged
  • Scalp
  • Skin Neoplasms / metabolism*
  • Skin Neoplasms / pathology
  • Skin Neoplasms / secondary

Substances

  • Biomarkers, Tumor