Histopathological Study of Skin Lesions in a Tertiary Care Hospital: A Descriptive Cross-sectional Study

ABSTRACT Introduction: Skin diseases are much common in developing countries. The spectrum varies according to geographic distribution, gender, age, and coexisting disorder. We conducted this study to find out the prevalence of different skin lesions and to evaluate their frequency and site of distribution. Methods: A descriptive cross-sectional study was done in the pathology department of Kathmandu Medical college from June 2019 to November 2019 after ethical clearance. The skin biopsies were processed, sectioned and stained with Haematoxylin and eosin and evaluated. A convenience sampling method was used. Data was collected and entry was done in Statistical Packages for Social Services version 20.0, point estimate at 95% Confidence Interval was calculated along with frequency and proportion for binary data. Results: Among 133 skin biopsies examined, noninfectious vesicobullous and vesicopustular disease were found in 42 (46.6%) cases followed by microbial disease in 22 (24.5%) and noninfectious erythematous papular and squamous disease in 21 (23.4%) cases. Spongiotic dermatitis was the most common vesicobullous disease seen in 26 (28.9%) cases. Leprosy was the commonest microbial disease found in 7 (7.8%) cases. The commonest noninfectious erythematous papular and squamous disease was erythema dyschromicum perstans seen in 7 (7.8%) cases. The commonest neoplastic lesion was keratinocytic tumor seen in 12 (32.5%) cases. The commonest tumor of the skin was intradermal nevus seen in 6 (16.3%) cases. Upper extremities were the most frequently involved site by skin lesions. Conclusions: Spongiotic dermatitis is a predominating non-neoplastic and overall skin lesion which was similar to the other studies done. Histopathological examination is the gold standard for the proper diagnosis as histomorphological features distinguish various skin lesions.


INTRODUCTION
Skin diseases affect all age groups and are much common in developing countries. In the field of dermatology, 2000 different skin diseases are well known. 1 The pattern of skin disease varies from country to country and region to region within the same country. Various factors such as racial, environment and social customs influence skin disease. 2 Skin biopsies are often performed as many of the diseases have clinical overlaps which range from simple acne to serious disorder like toxic epidermal necrolysis and neoplastic condition. 1,3 The clinically different skin lesions may show similar histologic findings, therefore, a correlation between clinical presentation and history with histopathological findings improves the diagnostic JNMA I VOL 58 I ISSUE 224 I APRIL 2020 specificity of the skin lesions. 4 This study was done to find out the prevalence of various skin lesions and their frequency as well as site of distribution.

METHODS
This descriptive cross-sectional study was conducted among the patients visiting Kathmandu Medical College Public Limited, Sinamangal, Nepal from June 2019 to November 2019. The ethical approval for the study was taken from the Institutional Review Committee of Kathmandu Medical College Teaching Hospital, with reference number 3105201114. Data was collected from the patients from whom biopsies of skin lesions had been taken. All the patients who were subjected to skin biopsy were included in this study. Inadequate skin biopsies and cystic skin lesions were excluded from the study. The biopsies taken were fixed in 10% formalin and then processed. Four microns thick sections were taken and stained with Haematoxylin and Eosin stain (H&E). Special stains like Ziehl-Neelsen (ZN), Periodic Acid Schiff (PAS) and Fite-Faraco were used whenever required. Convenient sampling was done and sample size was calculated using the following formula.
where, n= sample size p= prevalence of 9.6 % q= 1-p e= margin of error (5%) Z= 1.96 at 95% CI The data was entered in SPSS (Statistical Packages for Social Services) version 20.0. The descriptive statistical analysis was done.

(100)
The most common non-neoplastic histopathological pattern observed was noninfectious vesicobullous and vesicopustular disease comprising of 42 (46.6%) cases followed by microbial disease 22 (24.5%) cases and noninfectious erythematous papular and squamous disease 21 (23.4%) cases. Connective tissue disease was the least commonly seen in 5 (5.5%) cases. The most common vesicopustular disease was spongiotic dermatitis comprising 26 (28.9%) cases followed by lichen simplex chronicus seen in 10 (11.1%) cases. Leprosy was the commonest microbial disease seen in 7 (7.8%) cases followed by verruca in 6 (6.7%) and dermatophytosis seen in 4 (4.5%) cases. Among noninfectious erythematous papular and squamous disease, erythema dyschromicum perstans was the commonest disease seen in 7 (7.8%) cases followed by lichen planus seen in 5 (5.6%) cases ( Table 2). Among neoplastic skin lesions, keratinocytic tumor was most commonly seen in 12 (32.5%) cases followed by melanocytic tumors seen in 9 (24.3%) cases. The prevalence of appendageal tumors and soft tissue tumor was equal. Both seborrheic keratosis and squamous cell carcinoma was a commonest keratinocytic tumor seen in 4 (10.8%) cases respectively. Intradermal nevus was the commonest melanocytic and overall skin tumor observed in 6 (16.3%) cases (Table 3).  (Table 4). a commonest papulosquamous disease found in our study. Leprosy (7.8%) was a commonest infective skin lesion in our study followed by verruca (6.7%) and dermatophytosis (4.5%). Agrawal et al. also found leprosy as a commonest infectious skin disease in their study. 11 In contrast to our study, previous studies done in Nepal by Karn et al. 13 and Walker et al. 14 found dermatophytosis as the commonest infective skin lesion and they concluded that hot and humid climatic conditions in a certain geographic region may be the possible cause for the increase in prevalence in fungal infections.
The common neoplastic lesion observed in our study was keratinocytic tumor (32.5%) followed by the melanocytic tumor (24.3%). However, the overall commonest lesion was intradermal nevus. The skin lesions were commonly seen in the upper and lower extremities in our study. Adhikari et al. in their study also found upper and lower extremities as the commonest site of involvement by skin lesions.1 However, in contrast to our study, Bezbaruah R et al. found eyelid and lip as a frequent site of involvement. 5

CONCLUSIONS
Prevalence of spongiotic dermatitis was higher which was similar to the other studies done. We observed a wide spectrum of skin lesions ranging from dermatitis to malignant neoplasm. The importance of specific histomorphological features lies in distinguishing various skin lesions and play a major role in making the final diagnosis of these diverse skin lesions. This highlights the role of histopathological examination for the proper management of patient.