Linear basal cell carcinomas: report of multiple sequential tumors localized to a radiotherapy port and review of the literature.

Linear basal cell carcinoma, an uncommon variant of basal cell carcinoma, was first described in 1985. The cases of eight additional patients with this morphologically distinctive variant have been published subsequently. We describe a woman who sequentially developed three linear basal cell carcinomas located within her radiotherapy port. Including our patient, 12 linear basal cell carcinomas have been reported in 10 patients (4 men and 6 women) ranging from ages 40 to 77 years. The tumors were located most often on the head and neck (9 cancers); other sites involved the shoulders (2 cancers) and posterior thorax (1 cancer). All of the tumors were excised without recurrence. Various mechanisms have been postulated to account for this morphologic variant of basal cell carcinomas including a Koebner phenomenon or limited lateral spread of the cancer secondary to dermal fibrosis, or both.