Basal cell carcinoma, oculo-cutaneous albinism and actinic keratosis in a native Indian.

The report highlights the occurrence of basal cell carcinoma in a native Indian with oculo-cutaneous albinism, an association not frequently encountered. The clinical and histopathological features, which assisted to form the diagnosis, are outlined. A high degree of suspicion and timely recognition of the potentially aggressive neoplasm, under this unusual circumstance, is the key to its diagnosis.

What was known?

The occurrence of squamous cell carcinoma in actinic keratosis is well-known and has been documented time and again.

Introduction

Non-melanoma skin cancer (NMSC) is the most common variant of cutaneous malignancy, white population being the most susceptible. Its incidence shares an inverse relationship with the degree of pigmentation. Photo-protective effect of eu-melanin seemed to have a role to play in determining its pattern of incidence. Although its worldwide incidence is skewed toward basal cell carcinoma (BCC), dark-skinned Indians are less prone to develop the condition.[1] However, in the settings of genodermatoses,[2] comprising oculo-cutaneous albinism (OCA), and Hermansky-Pudlak syndrome (HPS), BCC may be a relatively common finding. Reduction/complete absence of melanin may lead to photosensitivity and high-risk cutaneous signs such as freckles, actinic keratosis, and BCC. Here we report an Indian native of oculo-cutaneous albinism, freckling, actinic keratosis, and ulcerative BCC.

Case Report

A 56-year-old farmer, a known case of type IA OCA, presented with the complaint of discomfort in daylight, diminished vision, and a slowly progressive asymptomatic, red, raised eruption over the back for the past 10 years. He was born out of a consanguineous marriage. He has been suffering since early childhood. He had irregular, dark, flat lesions, initially overexposed parts, which later spread to cover the whole body. Some of the flat lesions turned darker in color, hard, and raised with the increasing age. He also started developing these lesions over the face, arms, and back. He had got them removed surgically on several occasions, without any tangible outcome. There was no history of bleeding, itching, and/or rapid increase in size.

Skin surface examination, was conspicuous by the absence of color in the skin (chalky white), hair, and eyes. It was accompanied by reduced visual acuity and photophobia. Multiple irregular, brown-to-amber color branched macules, the dendritic freckles were located over exposed and covered parts of the skin. In addition, a keratotic, speckled pigmentation plaque with rolled out margins of the size of 5-7 cm was present over the left scapular region [Figure 1a]. Smaller lesions of similar morphology were also identified over the arms and pre-auricular area [Figure 1b]. There was no evidence of pallor, cyanosis, icterus, lymphadenopathy, and organomegaly.

Figure 1

(a, b) Basel cell carcinoma occupying left scapular region of the back and pre-auricular region of the face

Complete hemogram, liver and renal function tests were unremarkable. So also were the chest radiograph and abdominal ultrasonography.

Hematoxylin-eosin-stained sections prepared from the biopsy taken from the plaque revealed a basaloid proliferation of cells arranged in nests, with peripheral palisading [Figure 2]. Retraction artifact was seen separating some of these cell nests from the surrounding stroma [Figure 3]. Foci of squamous differentiation were evident in the upper dermis. Accordingly, the diagnosis of BCC was returned. Excision biopsy of the keratotic plaque from the auricle revealed keratinocyte atypia, solar elastosis, and melanophages in the dermis consistent with actinic keratosis [Figure 4].

Figure 2

Sections prepared from the biopsy from an exophytic plaque. Proliferation of basaloid cells disposed in nests in the dermis, (H and E, ×40)

Figure 3

Sections prepared from the biopsy from an exophytic plaque. Higher magnification depicting prominent peripheral palisading, and retraction space, (H and E, ×100)

Figure 4

Sections prepared from the biopsy of the keratotic plaque from the auricle. Note the keratinocyte atypia in the lower two-thirds of the epidermis; and melanophages, and solar elastosis in the dermis, (H and E, ×40)

Discussion

For the darker races, where melanin confers natural photo-protection, albinism poses as an established risk attribute for all three forms of cutaneous malignancies.[34] Although squamous cell carcinoma (SCC) is usual, basal cell carcinomas have also been reported in albino.[56] It frequently encounter in females than males. Actinic keratosis as a morphological expression of squamous cell carcinoma is well-known. However, recent studies[7] have incriminated basal cells in the histo-genesis of actinic keratosis. Another fascinating entity that has emerged in recent times is baso-squamous cell carcinoma,[89] where coexisting features of both SCC and BCC have been encountered. Such a case has also been reported in an albino Indian.[10] In our case, the clinical picture, in the setting of albinism and cutaneous features of photo-damage suggested a diagnosis of SCC, but consideration of the sites of involvement, duration and absence of metastasis suggested otherwise. Histopathological examination confirmed the diagnosis of BCC. Our case represents the documented cohabitation of cutaneous signs of photo-damage,[11] actinic keratosis, dendritic freckles in the perspective of OCA. The occurrence of BCC, therefore, is fascinating for it is infrequently reported in these settings.

Learning Inputs/Conclusions

OCA is an established risk factor for all the three major forms of skin cancers, due to reduction and/or complete absence of melanin

Although SCC is common, the presence of BCC is not that infrequent and should be ‘suspected’

Irrespective of the clinical morphology, histopathology is imperative

Under the circumstances, apart from identification of pure SCC/BCC, keratinizing BCC and baso-squamous carcinoma should be kept in mind.

What is new?

Basal cells in the histogenesis of actinic keratosis has recently been incriminated, enforcing this new concept.