Basosquamous cell carcinoma in organ transplant patients: a clinicopathologic study.

BACKGROUND: Basosquamous cell carcinoma (BSCC) is a poorly known tumor showing pathological features of both basal and squamous cell carcinomas. BSCC has never been specifically studied in organ transplant recipients (OTRs). OBJECTIVE: We sought to study the clinicopathologic features of BSCC in OTRs and compare them with BSCC from nongrafted patients. METHODS: Tumors diagnosed as BSCC were re-evaluated pathologically and immunohistochemically for the expression of the human epithelial antigen to confirm the diagnosis. The clinicopathologic features of BSCC in OTRs were compared with 30 BSCC obtained from nongrafted patients. RESULTS: In our cohort of 3520 OTRs, 12 patients (0.34%) developed BSCC after a mean postgraft delay of 13.2 years, ie, later than other skin carcinomas. As compared with control patients, the age of OTRs with BSCC and the tumor thickness were significantly lower. BSCC were located on the head/neck in both groups in more than 75% of cases. No metastases developed in OTRs (mean follow-up 2.8 years). During the follow-up period (mean 16 years), OTRs with BSCC developed up to 220 additional premalignant and malignant skin tumors. After the diagnosis of BSCC, two patients developed lymph node metastasis of distinct squamous cell carcinoma. LIMITATIONS: This is a single-center, retrospective study. CONCLUSIONS: BSCC is a rare tumor, even in OTRs who are at high risk of carcinomas. Its incidence (0.34%) is comparable with that of cutaneous lymphomas and melanomas, and much lower than that of other nonmelanoma skin cancers. Contrary to previous reports, BSCC do not seem to behave more aggressively than other nonmelanoma skin cancers.