Histomorphological evaluation of non-neoplastic cutaneous disorders

Skin, the largest organ of the body functions as a protective covering to internal viscera; provides a passive protective barrier to fluid loss and mechanical damage; has a sensory contribution and endocrine role of vitamin D synthesis. A spectrum of conditions varying from wrinkles and hair loss, blisters, and rashes to life-threatening malignancies may be consequences of imbalances in factors that maintain the homeostasis amongst skin cells.1 Most skin conditions are diagnosed based on the patient’s history, anatomical distribution, and clinical appearance of the Original Article


INTRODUCTION
Skin, the largest organ of the body functions as a protective covering to internal viscera; provides a passive protective barrier to fluid loss and mechanical damage; has a sensory contribution and endocrine role of vitamin D synthesis. A spectrum of conditions varying from wrinkles and hair loss, blisters, and rashes to life-threatening malignancies may be consequences of imbalances in factors that maintain the homeostasis amongst skin cells. 1 Most skin conditions are diagnosed based on the patient's history, anatomical distribution, and clinical appearance of the lesion. However, the restriction of clinical presentation to limited changes for a wide gamut of cutaneous pathology causes diagnostic challenges. In such scenarios, a skin biopsy can contribute by providing a definitive answer appropriate to the patient's clinical context or by ruling out important pathology even though an exact diagnosis cannot be made and thus guides further management. 2 Special stains, immunohistochemistry, immunofluorescence, and molecular techniques are additional modalities that may aid in reaching a diagnostic conclusion.
The current study aims to find the prevalence of various non-neoplastic skin diseases according to its diagnostic categories and determine its age and gender-wise distribution over a study period of three years. This study could help us gain an insight into the spectrum of non-neoplastic diseases existing in the Nepalese population.

MATERIALS AND METHODS
This is a retrospective descriptive hospital-based study performed at the Department of Pathology at Patan Academy of Health Sciences. This study was conducted over three years, from April 2017 to March 2020. The study included skin biopsies that were received at histopathology laboratory and diagnosed as non-neoplastic skin diseases. The material is comprised of punch, incisional, and excisional biopsy specimens. Neoplastic lesions, skin biopsies with descriptive reports, and those without definitive diagnostic opinions were excluded from the study. All the relevant data were retrieved from the archived reports from the histopathology database and entered and coded in an Excel sheet. The data variables were histopathology number, age, gender, anatomical site, and diagnosis of the lesions. Analysis of the data was performed using SPSS version 17.0. The variables were summarized using mean, percentage, and range, and the data was represented with tables and figures.

RESULTS
During the study period, we received 565 skin biopsies at our institution. Among them, non-neoplastic lesions constituted 180 cases (31.86%) and were included in our study. Non-neoplastic skin lesions were present in all DOI : 10    Molluscum contagiosum ( Figure 2) 3 8.9 Verruca plana 1 2.9 Verruca vulgaris 5 14.7 Fungal Sporotrichosis 2 5.9 Protozoan & Parasitic Cutaneous leishmaniasis ( Figure 3) 4 11.8 Arthropod bite reaction 3 8.9 Total 34 100 age groups. The age ranged from 5 months, a male child diagnosed with urticaria pigmentosa to 95 years male with borderline tuberculoid leprosy. The mean age of the patients with non-neoplastic lesions was 36 years. The maximum number of patients was found in 31-40 years followed by 11-20 years of age group. There was no overall particular gender predilection with a male to female ratio of 1.02:1. However, significant gender preferences were noted in various diagnostic categories as shown in Figure 1. Microbial diseases, inflammatory disease of hair follicles, sweat glands, and cartilage and vascular diseases had male preponderance whereas connective tissue diseases and noninfectious erythematous, papular, and squamous diseases were more common in females. Lichen planus followed by urticaria was the most frequently encountered lesions in non-infectious erythematous, papular, and squamous diseases ( Table 2). Leprosy was the commonest microbial disease (Table 3). In the noninfectious vesiculobullous and vesiculopustular category, spongiotic dermatitis was most prevalent (Table 4). Overall, spongiotic dermatitis followed by lichen planus, leprosy, and calcinosis cutis were the commonest non-neoplastic disorders.

DISCUSSION
The existing pattern of dermatological diseases is influenced  by numerous factors like environment, economy, literacy, racial, and social customs. It varies amongst different countries as well as within various geographical regions of a country. 3 We received 565 skin biopsies at our institution and this represented 5.7% of all the histopathology specimens submitted to the laboratory over the study period. Among them, 294 (52.04%) were neoplastic lesions comprising of 253 (44.78%) benign and 41 (7.26%) malignant neoplasms. Non-neoplastic lesions constituted 180 cases (31.86%) and were included in our study. Thus, neoplastic lesions were more common than non-neoplastic ones. This could be attributed to the possibility that many non-neoplastic lesions are not subjected to biopsy as they are diagnosed clinically and managed accordingly. The ratio of benign to malignant neoplasm was 6.1:1. The remaining 91 cases (16.1%) showed either a descriptive report or was inconclusive for a definitive diagnostic conclusion.
Non-neoplastic skin lesions were present in all age groups.
The age ranged from 5 months, a male child diagnosed with urticaria pigmentosa to 95 years male with borderline tuberculoid leprosy. The mean age of the patients with non-neoplastic lesions was 36 years. The age distribution pattern revealed that the maximum number of patients was found in 31-40 years. This finding is comparable to studies performed in Nepal by Adhikari et al 4 and in neighboring country India by D' Costa et al 5 and Gupta et al. 6 In contrast, the maximum number of patients were present in a younger age range of 21-30 years in a study conducted by Veldurthy et al. 7 There was no overall particular gender predilection with male to female ratio of 1.02:1 which is in accordance with numerous studies. 4,8,9 Some studies 10 showed female preponderance whereas male predominance was observed in other studies. 7,11 However, we noted significant gender preferences in individual diagnostic categories. Microbial diseases, inflammatory disease of hair follicles, sweat glands, and cartilage and vascular diseases had male preponderance whereas connective tissue diseases and non-infectious   cutis were the commonest diseases in these categories respectively. The residual categories each comprised less than 3.5% of the total cases. Overall, spongiotic dermatitis followed by lichen planus, leprosy, and calcinosis cutis were the commonest non-neoplastic disorders. Spongiotic dermatitis followed by Erythema dyschromicum perstans was commonest in a study by Adhikari et al 4 and leprosy followed by lichen planus was most prevalent in studies by Gupta et al 6 as well as Kumar et al 10 .

CONCLUSIONS
Amongst the diagnostic categories, the prevalence of noninfectious erythematous, papular, and squamous diseases was highest followed by microbial diseases and non-infectious vesiculobullous and vesiculopustular diseases. Overall, in this histopathological study, spongiotic dermatitis followed by lichen planus, leprosy, and calcinosis cutis were the commonest non-neoplastic disorder.