Diagnosis, investigation, and treatment of occult breast cancer: A case report and systematic review of the literature

Background

Occult breast cancer (OBC) is an uncommon diagnosis that rarely causes skin metastasis. Our aim herein was to report a case of OBC with cutaneous metastasis and to systematically review the current evidence on the investigation, diagnosis, and treatment of such cases.

Methods

We followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). A comprehensive search was conducted on MEDLINE, Embase, Cochrane Library, and Google Scholar. We included studies in English published from inception to August 2022 that included male or female patients who presented with OBC metastasis to the skin and that reported clinical outcomes of interest.

Results

We identified 854 articles, 13 of which were included in our review. The articles were case reports published between 2009 and 2022 and included 13 patients. The commonest site for skin lesions was the chest (n = 7), followed by the axilla (n = 5), of which 2 were bilateral. The skin lesions were nodular in 5 cases, macular in 2 cases, urticarial in 2 cases, papular in 1 case, and ulcerating in 2 cases. Skin metastasis was positive for estrogen receptor in 8 cases, progesterone receptor in 7 cases, cytokeratin 7 in 6 cases, and GATA binding protein 3 in 5 cases. Medical management was mostly by chemotherapy (n = 7) and hormonal therapy (n = 3). Surgical excision of the skin lesion was performed in 5 cases.

Conclusion

Cutaneous breast metastasis in the absence of the primary lesion is a rare phenomenon. Most cases reviewed were managed with multimodal approach including surgical and medical management. This review provides reference for physicians coming across similar cases.