In transit metastases of cutaneous squamous cell carcinoma: A single institution case series

Abstract

To the Editor: In transit metastasis of cutaneous squamous cell carcinoma (cSCC), defined as foci of cSCC originating within dermal or subcutaneous tissue, clinically distinct from the primary tumor, and occurring before the first echelon of regional lymph nodes, is a rare entity and manifestation of end-stage disease. Immunosuppressed patients, specifically solid organ transplant recipients, are at an increased risk of invasive and metastatic cSCC. Since 2004, there have been 3 published case series describing in transit metastasis of cSCC including a total of 124 patients. 1 Carucci J.A. Martinez J.C. Zeitouni N.C. et al. In-transit metastasis from primary cutaneous squamous cell carcinoma in organ transplant recipients and nonimmunosuppressed patients: clinical characteristics, management, and outcome in a series of 21 patients. Dermatol Surg. 2004; 30: 651-655 Crossref PubMed Google Scholar , 2 Ma J.H.Y. Wu A. Veness M. et al. In-transit metastasis from squamous cell carcinoma. Dermatol Surg. 2016; 42: 1285-1292 Crossref PubMed Scopus (14) Google Scholar , 3 Smile T.D. Ruiz E.S. Kus K.J.B. et al. Implications of satellitosis or in-transit metastasis in cutaneous squamous cell carcinoma: a prognostic omission in cancer staging systems. JAMA Dermatol. 2022; 158: 390-394 Crossref Scopus (0) Google Scholar Since the first 2 case series, therapy has shifted to multimodal treatment. 1 Carucci J.A. Martinez J.C. Zeitouni N.C. et al. In-transit metastasis from primary cutaneous squamous cell carcinoma in organ transplant recipients and nonimmunosuppressed patients: clinical characteristics, management, and outcome in a series of 21 patients. Dermatol Surg. 2004; 30: 651-655 Crossref PubMed Google Scholar ,2 Ma J.H.Y. Wu A. Veness M. et al. In-transit metastasis from squamous cell carcinoma. Dermatol Surg. 2016; 42: 1285-1292 Crossref PubMed Scopus (14) Google Scholar We performed a retrospective review of cSCC patients with in transit metastasis from 2015 to 2021 at a single academic institution.