Histopathological evaluation of tumours and tumour like lesions of skin and adnexa

Materials and Methods: The study was conducted at Department of Pathology of Tribhuvan University Teaching Hospital. It was a one year prospective study which enrolled 238 cases of skin biopsies after histopathological confirmation of tumours and tumour like lesions. The specimens were processed by standard method and Hematoxylin and Eosin stained sections were examined. Data entry and analysis was done by using SPSS 20 version.

mutagen, is not considered significant because it is filtered out by the ozone layer. 6 Diagnosis of adnexal neoplasms presents unique difficulties, related to the wide pathological variety, substantial frequency of one lesion exhibiting histological features of two or more adnexal lines and the complicated nomenclature. 7 This prospective study was conducted to estimate the frequency, age, sex and site wise distribution of tumour and tumour like lesions encountered in the department over a period of one year.

MATERIALS AND METHODS
The study is a hospital based cross sectional prospective study carried out from 1st November 2014 to 31st October 2015 at Department of Pathology, Maharajgunj Medical Campus, Kathmandu, Nepal. Permission was obtained from ethical review committee prior to the study. The study included all the patients presenting with tumours (benign and malignant) and tumour like lesions arising from skin, adnexa and soft tissue tumour arising from the dermis diagnosed on histopathological examination.
All the diagnosed cases coming for follow up, in which biopsy was done previously, tumours arising from subcutaneous tissue, suboptimal biopsy sample, and tumors and tumor like lesions in the genital region were excluded. All the received skin biopsy specimens were fixed in 10% formalin and subjected for tissue processing, embedded in paraffin and block was made to obtain 5 micron sections. The sections stained with Hematoxylin and Eosin (H and E) were examined. The data collection was done in predesigned proforma and data entry was done in SPSS and results were computed using Statistical Package for Social Sciences (SPSS) version 20.

RESULTS
During the study period, 395 skin biopsies were received, out of which 238 cases were histopathologically diagnosed as tumours and tumour like lesions of skin and adnexa. Tumours and tumour like lesions of skin and adnexa were most commonly seen in 11-30 years (n=94; 39.4%) of age. (Table 1) Peak of benign neoplasms was seen at 11-30 years (n=58; 24.4%), thereafter the frequency decreased with increasing age. Malignant neoplasms showed a peak at 61-80 years (n=18; 7.6%). Before 60 and after 80 years there was not much variation in frequency of tumours. Tumour like lesions showed a peak at third decade of life (Table 1).
There were 135 male and 103 female with M:F ratio of 1.3:1. Male to female ratio for benign tumour, malignant tumour and tumour like lesions were 1.2:1, 1.8:1 and 1.12:1 respectively. (Table 2) The frequency of tumour and tumour like lesions decreased from face to trunk. Sixty seven percent of total benign tumours and 65% of total malignant tumours occurred in face and scalp. (Table 3).
Basal cell carcinoma was the most common malignant neoplasm in face followed by squamous cell carcinoma and basosquamous carcinoma ( fig.1) . Squamous cell carcinoma was the most ubiquitous which was seen at almost all the locations. Of 20 cases of benign adnexal tumors, 11 were seen in face and tumours with eccrine and apocrine differentiation was the most common.
Out of 238 cases, tumour constituted 185 cases (77.8%) and tumour like lesions constituted 53 cases (22.2%). Intradermal melanocytic naevus was the most common tumour followed by SCC and squamous papilloma. Among the tumour like lesions epidermal cysts was most common type followed by dermoid cysts and trichilemmal cysts. Benign neoplasms were the most common lesions (60%) followed by tumour like lesions (22%) and malignant neoplasms (18%).  Benign soft tissue tumours of dermis were the most common type of benign neoplasms, followed by keratinocytic tumours, melanocytic naevi and adnexal tumours. Out of 50 cases of soft tissue tumour of dermis, vascular tumours were commonest. Out of 20 cases of benign adnexal tumours, pilomatricoma (2.8%) and spiradenoma (2.8%) were the commonest. Benign vascular neoplasms (total 39 cases) constituted 16.3% of total biopsies. They constituted 27.5% of benign neoplasms out of which cavernous hemangioma (36%) was the most common. (Table 5) Malignant tumours constituted 18% (43 cases) of total cases. Keratinocytic tumour was the commonest. Melanoma and adnexal carcinoma constituted three cases each. Squamous cell carcinoma (SCC) was the commonest carcinoma followed by basal cell carcinoma (BCC) Table 6 .
Out of 53 cases (22.3% of total cases) of tumour like lesions, epidermal cysts were the commonest, followed by dermoid cysts and trichilemmal cysts ( fig. 2).

DISCUSSION
Skin biopsy constitutes a simple and inexpensive procedure performed in the dermatology setting which facilitates clinical decisions regarding diagnosis and treatment.
Various studies consider histological confirmation as the standard for the correct diagnosis in dermatology.
In the present study skin biopsies constituted 5.4% of the total surgical pathology specimen which is comparable to the study done by Bari et al 8 where skin biopsies constituted 5.38% of total surgical specimens. Tumours and tumour like lesions of skin constituted 60.2% of the total skin biopsies in this study.
The present study showed male predominance with male to female ratio of 1.3:1. Both benign and malignant tumours were more common in males than females which correlated with the study done by Bari et al. 8 In the present study 55.6% of benign neoplasms and 65.1% of malignant neoplasms were seen in males, whereas 44.3% of benign neoplasms and 34.8% of malignant neoplasms were seen in females. Tumour like lesions were also more common in male (52.8%) than female (47.1%) which correlated with a similar study conducted on tumour like lesions of skin by Bari et al. 9 As in our study, both benign and malignant skin tumours showed male predominance in a study done   In various studies done in Singapore and India, SCC was more common in males than females as in present study. 3,10,11 All six cases of basosquamous carcinoma, were seen in males. In a study done by Martin et al 12 , males (75%) were more commonly affected than females (25%). Out of 18 cases of SCC, 12 cases were seen in males and six cases were seen in females. Hence, the present study showed that frequency of SCC and basosquamous carcinoma in men is higher than in women, which may be attributable to the cumulative effect of sun exposure in males, who work outdoors more commonly than women.
In the present study, benign neoplasms of skin were common in younger age groups (11-30 years) ( In the present study, tumour like lesions were most commonly noted in third decade where as in study done by Bari et al 9 , maximum cases of tumour like lesions occurred in fourth to fifth decade of life. In this study, out of 238 cases, benign tumours were most common followed by tumour like lesions of skin and adnexa and malignant tumours which correlated with study of Bari  Out of 142 cases (60%) of benign neoplasms, soft tissue tumour of dermis were commonest followed by keratinocytic tumours. Benign vascular tumours were the most common type of soft tissue tumour of dermis of which cavernous hemangioma (36%) was commonest. However, in a study done by Margileth and Museles 14 capillary hemangioma (81%) was the most common type of vascular tumour followed by cavernous hemangioma (7%).
Adnexal tumour comprised 10% of total cases, out of which benign adnexal neoplasms (87.0%) were more common than malignant adnexal neoplasm (13.0%). A study by Sharma et al 2 also showed that benign adnexal tumours (80.3%) were more common than malignant adnexal tumours (19.6%). The face (56.5%) was the commonest site of involvement by adnexal tumour followed by scalp (26.1%). A similar study by Nair16 in India also showed face to be the commonest site (76%) followed by scalp (12.1%).
In the present study, tumours with eccrine differentiation (7%) was the commonest benign adnexal neoplasm. Spiradenoma was the commonest eccrine tumour. Tumour malignant keratinocytic tumour were the commonest followed by three cases each of melanoma and malignant adnexal tumour.The finding in this study was similar to four studies done in India by Bari et al, 8 Adinarayan and Krishnamurthy, 10 Gundalli et al, 11 Bhudraja SN et al. 18 However, in a similar study by Hajheydari et al 19 in Iran, BCC (68.4%) exceeded SCC (23%), followed by melanoma (3.3%).The frequencies of different malignant tumours in different studies are compared in Table 8.
In present study, out of total number of cases, six cases of SCC and nine cases of BCC were noted on face. In a similar study done in Iran by Hajheydari 19 , head and neck was the most common site of involvement by SCC (49%) and BCC (93%). The reason for common involvement of face by these tumours could be due to actinic exposure.
Tumour like lesions of skin and adnexa constituted 53 cases of total surgical biopsies (0.7% of total 7275 cases).
with hair follicle differentiation followed the eccrine tumours (Table 5), which is similar to study by Nair 16 where eccrine differentiation constituted the maximum cases (52%) followed by tumours with hair follicle differentiation (36.3%).
In the present study there were three cases of malignant adnexal tumours (6.9% of total malignant tumours), with one case each of apocrine carcinoma ( fig.3), microcystic adnexal carcinoma and sebaceous carcinoma.
In the present study, malignant neoplasm constituted 18% of total cases (43 cases out of total 238 cases), of which

CONCLUSION
Biopsies for tumours and tumour like lesions of skin and adnexa constituted the majority of skin biopsies. Frequency of skin biopsies for tumour and tumour like lesions was at 11-30 year of age groups. Face was the most common location for such lesions. Benign neoplasms outnumbered the malignant neoplasms. Tumour like lesions are clinically diagnosed by their presentation. However, early biopsy would help in rulling out any possibilities of malignancies.