Late onset of first skin cancer in a 56-old patient with xeroderma pigmentosum

Xeroderma pigmentosum is a rare autosomal recessive genodermatosis caused by defective DNA repair and characterized by extreme photosensitivity, freckling and skin cancer. Seven variants of the disease, known as complementation groups, from XP-A to XP-G, have been described, depending on the deficient gene [1]. The early skin findings include photosensitivity and lentigines with the median onset before 2 years of age. The first malignant tumours may develop as early as the third or fourth year, with a median age of onset of 8 years [1]. Most of the tumours occur on the head and neck [2]. Patients in the second decade have an exponential increase in melanoma and non-melanoma skin cancers compared to the general population. The disease is often fatal before the age of 10 years, and worldwide two-thirds die before 20 years of age [1]. Survival beyond the third decade of life is unusual [3]. Here we report a case of a patient with xeroderma pigmentosum who presented with her first tumour in the fifth decade.
A 56-year-old woman presented with an ulcerative growth on right side of her lower lip, present for 3 months. She had a history of photosensitivity, progressive pigmentary skin changes and ocular complaints since early childhood. She was otherwise well with no systemic complaints. Examination revealed mottled pigmentation predominantly over the face, upper back, chest and exposed part of limbs with atrophy, depigmentation and telangiectasia over the butterfly area of the face (fig. 1 A). An ulceroproliferative growth was present involving two-thirds of the lower lip on the right side, extending onto the buccal mucosa (fig. 1 B). Ocular examination showed loss of eyelashes, conjunctival congestion and corneal clouding with decreased visual acuity. Diagnosis of xeroderma pigmentosum with squamous cell carcinoma of the lower lip (T3N0M0) was made. Wide local excision of the growth with bilateral Karapandzic flap reconstruction was done. Histopathology of the growth revealed poorly differentiated squamous cell carcinoma (fig. 1 C). The patient was advised strict photoprotection, use of broad spectrum sunscreen and regular follow-up.
Xeroderma pigmentosum is a disfiguring and potentially life-threatening hereditary disorder characterized by photosensitivity, pigmentary changes, premature skin aging, and development of a malignant tumour at a very young age [4]. The first symptoms are noticed between the sixth month and the third year in over 75%...


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