Study of basal cell carcinoma and its histopathological variants

1Department of Pathology, S.Nijalingappa Medical College, Bagalkot, Karnataka, India, 2Department of Obstetrics and Gynaecology, S.Nijalingappa Medical College, Bagalkot, Karnataka, India, 3Department of Surgery, ABVRH, Sawangi, Wardha, Maharashtra, India, 4Department of Surgery, Devraj urs Medical College, Kolar, Karnataka, India, 5Department of Anaesthesia, ABVRH, Sawangi, Wardha, Maharashtra, India, 6Department of Obstetrics and Gynaecology, Devraj urs Medical College, Kolar, Karnataka, India


INTRODUCTION
The first description of basal cell carcinoma (BCC) was by Jacob in 1827. BCC is the most common malignant skin tumor, but the incidence in Asian races is lower than in the white race. The incidence of BCC in Indian literature ranges from 12% to 30%.BCC is seen almost exclusively on hair bearing skin especially on the face. BCC generally occurs in adults. BCC may develop in children under following circumstances: Nevoid basal cell epithelioma syndrome, in pre-existing organoid nevus and in xeroderma pigmentosa [1].
Scriverer Y et al in his study on 13,457 patients with BCC have shown that nodular and morphoeiform types predominate on the forehead where as the trunk is the most common site for the superficial type [3].
Histopathology: BCC tend to share the common features of a predominant basal cell type, peripheral palisading of cell nuclei, a specialized stroma, and clefting artifact between the epithelium and the stroma.
Prognosis and predictive factors: BCC are locally invasive tumours and metastases occur in less than 1 in 10,000 tumours. Morbidity is increased with deeply invasive tumours which may extend into the deep tissue to bone and follow fusion planes particularly on the face where they follow nerves through bony channels. Morbidity also increases with neglected tumours that may measure more than 10 cm in diameter and have been described as giant basal cell carcinomas. Multiple recurrences with deep residual tumour on the head may be associated with particular morbidity as basal cell carcinomas can ultimately penetrate the cranium. Increased recurrences are associated with infiltrative, morphoeic and micronodular BCC as surgical margins may be underestimated. BCC recurrences are more common in lesions on the nose and nasolabial fold, this may be in part due to the difficulty in achieving adequate margins in these sites. Tumours recurring after radiotherapy are usually aggressive and infiltrative [4].

MATERIALS AND METHODS
The present study was carried out in the department of pathology in a tertiary care centre. This study included tumours of epidermis along with melanocytic tumours and adnexal tumours of skin including secondaries without restricting the study to any particular age limit. Mesenchymal tumours of skin, haematological tumours of skin, neural tumours of skin, nonneoplastic lesions of skin and all tumours arising from mucosal area of mucocutaneous junction such as glans penis and eyelid margin were excluded. The study was prospective (2years) as well as retrospective (5 years) and was done during the period of September 2004 to September 2011 i.e., 7 years. Data for retrospective study was obtained from departmental records, tissue blocks and slides. Data for prospective study was obtained from clinical records, tissue specimens, tissue blocks and slides Clinical details were obtained and maintained according to the proforma. All the biopsies and resected specimens received in the histopathology section were immediately fixed in 10% formalin for 24 hours. Gross features of the specimen were noted. Multiple sections of the specimen were taken. Then they were processed and embedded in paraffin wax. Three-five microns thick sections were prepared and then stained with Haematoxylin & Eosin. Detailed study of the sections was performed under the light microscope and then the final diagnosis was given.
Ethical clearance: Ethical clearance has been obtained from Ethical committee of institution. Statistical methods applied: Following Statistical methods were applied in the present study.
Prior to the study, every patient gave written consent to the examination and biopsy after having been informed about the procedure and aim of the study.

RESULTS
In the present study 21 cases of BCC were seen and accounted for 26.25% of all the malignant tumours of skin (Figs 1 -6). Maximum number of cases were observed in 7 th decade. Mean age of patients was 65.6 years.           In the present study majority (85%) of the lesions of BCC were located on head and neck region, which is similar to the observations of Solanki et al [5] (94%), Chakravorthy et al [6] (90%) and Budhraja et al [7] (78%).
In the present study male to female ratio in the patients of BCC was 1.33:1. Solanki, et al found a male to female ratio of 1.26:1. Hence our findings are comparable with Solanki, et al [5].
And in present study the average age of cases of BCC was 65.6 years. Scrivener, et al noted average age as 65 years. Hence our findings are comparable to Scrivener, et al [3]. Table 5 shows comparison of histological types in BCC. Verrucous Carcinoma --   In the present study solid type of BCC was most common type which is comparable to the study of Solanki et al [5] as he also noted the solid type as most common type of BCC in his study of 172 cases.
BCCs constitute a small but significant proportion of patients with cancer. The skin is a complex organ. Because of its complexity a wide range of diseases develop from the skin including tumors from surface epidermis, epidermal appendages and dermal tissue.
The diagnosis of BCCs presents unique difficulties, in part, related to the wide variety of tumors and the complicated nomenclature. The study of histogenesis of the basal cell carcinomas is interesting, fascinating and challenging because of wide range of differentiation.
Histopathological study is one of the most valuable means of diagnosis in dermatopathology and the diagnosis of BCCs can be done by correlating clinical features, gross and histological appearances.
The present study emphasizes the various patterns of skin neoplasms in this geographic location in and around city.
Finally the quintescence of the subject of study of basal cell carcinomas is it's vastness, it's enormity and its interesting histomorphology.

CONCLUSIONS
In the present study majority (85%) of the lesions of BCC were located on head and neck region, average age of cases of basal cell carcinoma was 65.6 years, and solid type of BCC was most common type.

Statement of Human and Animal Rights
All procedures followed were in accordance with the ethical standards of the responsible committee on human experimentation (institutional and national) and with the Helsinki Declaration of 1975, as revised in 2008.

Statement of Informed Consent
Informed consent was obtained from all patients for being included in the study.