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

Abstract
In-transit metastases from cutaneous squamous cell carcinoma (SCC) may occur in organ transplant recipients and may indicate aggressive disease and poor prognosis. The objective of this study was to describe in-transit metastases from cutaneous SCC and to identify factors associated with this phenomenon in a series of 21 patients. We also attempted to evaluate outcome with respect to status as an organ transplant recipient or nonorgan transplant recipient. A multicenter case series of patients was reviewed; factors included clinical presentation, management, and outcome. Twenty-one patients, 15 organ transplant recipients, and 6 nontransplant recipients with in-transit metastases were reviewed. In-transit metastases presented most commonly as discrete, dermal papules distinct from but in the vicinity of the primary tumor site. Histologic differentiation was variable. At a mean follow up of 24 months, 33% the transplant patients had no evidence of disease compared with 80% of nontransplant patients. Thirty-three percent were dead from disease and 33% were alive with nodal or distant metastases. In contrast, 80% of nonimmunosuppressed patients had no evidence of disease and none had died at mean follow-up of 24 months. In-transit metastasis from cutaneous SCC is a unique presentation of metastatic SCC, more commonly described in organ transplant recipients, and is associated with poor prognosis in that group. This description represents the largest experience with in-transit metastases from cutaneous SCC in the literature.