REPORT OF A RARE MALIGNANCY- BASOSQUAMOUS CARCINOMA IN A XERODERMA PIGMENTOSUM PATIENT

Xeroderma pigmentosum (XP) is a rare autosomal recessive disorder, characterized by a genetic defect in DNA repair. The consequence is a high incidence of skin cancers on sun-exposed cutaneous surfaces of affected children. Patients with xeroderma pigmentosum who are younger than 20 years of age have a 1000-fold increased risk of developing skin cancer. Early detection of these malignancies is necessary because they are fast growing, metastasize early and lead to death. Early detection and treatment of these will reduce the morbidity and mortality. It is important to be aware of multiple malignancies of different types occur in the same patient with XP, commonly Basal cell carcinoma, Squamous cell carcinoma, Malignant Melanoma. Basosquamous carcinoma (BSC), a variant of BCC is a rare cutaneous tumor that has not been elaborately described in the dermatologic literature. It has been depicted as an aggressive tumor with a high incidence of distant metastasis. The diagnosis of basosquamous cell carcinoma is controversial. Basal cell carcinomas with areas of squamous cell carcinoma may be called Basosquamous Carcinoma. BSCs having tissue invasion similar to that of BCC or SCC but had a higher frequency of pulmonary metastasis than SCC. We present a case in which a longstanding lesion initially diagnosed as basal cell carcinoma by wedge biopsy was later found to have basosquamous histology