Nigerian Journal of Basic and Clinical Sciences

ORIGINAL ARTICLE
Year
: 2020  |  Volume : 17  |  Issue : 1  |  Page : 7--10

Morphological spectrum of excised conjunctival lesions in a tertiary hospital in North-Western Nigeria


Sadiq Hassan1, Saudat Garba Habib1, Imam Ibrahim Muhammad2, Philip Ifeanyichukwu Ebisike3, Abdu Lawan1,  
1 Department of Ophthalmology, Aminu Kano Teaching Hospital and Bayero University, Kano, Nigeria
2 Department of Histopathology, Aminu Kano Teaching Hospital and Bayero University, Kano, Nigeria
3 Department of Optometry, Aminu Kano Teaching Hospital and Bayero University, Kano, Nigeria

Correspondence Address:
Dr. Saudat Garba Habib
Department of Ophthalmology, Aminu Kano Teaching Hospital and Bayero University, Kano
Nigeria

Abstract

Context: Conjunctiva is a transparent membrane lining the inner surface of the eyelids and the globe up to the corneoscleral limbus. It is a common site for the growth of lesions in the eye. Depending on their origin, conjunctival lesions could be non-neoplastic and neoplastic. The neoplastic lesions are either benign or malignant. These lesions can be distinguished based on the patient's history, clinical presentation and histopathological features. Aims: In this study, the pattern of excised conjunctival lesions was determined. Methods and Material: This was a 6-year (2010–2015) retrospective study of all excised conjunctival lesions diagnosed at the Pathology Laboratory of Aminu Kano Teaching Hospital. Statistical analysis used: Data were analysed with Statistical Package for Social Sciences (version 20.0; SPSS, Chicago, IL, USA). Results: A total of 198 conjunctival lesions were diagnosed during the period. The male patients were 136 (68.70%), whereas the females were 62 (31.30%) with male-to-female ratio of 2.2:1, with a mean age ± standard deviation of 37.69 ± 16.39 years. The neoplastic nature of the lesions was as follows: 54 (27.3%) were malignant, 61 (30.8%) were pre-malignant and 83 (41.9%) were benign. The most common lesions observed were conjunctival squamous cell carcinoma, dysplasia and squamous papilloma with frequencies of 50 (25.30%), 46 (23.20%) and 24 (12.10%), respectively. Conclusions: Benign lesions are the most common conjunctival lesions, whereas squamous papilloma and squamous cell carcinoma are the most common benign and malignant lesions, respectively.



How to cite this article:
Hassan S, Habib SG, Muhammad II, Ebisike PI, Lawan A. Morphological spectrum of excised conjunctival lesions in a tertiary hospital in North-Western Nigeria.Niger J Basic Clin Sci 2020;17:7-10


How to cite this URL:
Hassan S, Habib SG, Muhammad II, Ebisike PI, Lawan A. Morphological spectrum of excised conjunctival lesions in a tertiary hospital in North-Western Nigeria. Niger J Basic Clin Sci [serial online] 2020 [cited 2020 Aug 14 ];17:7-10
Available from: http://www.njbcs.net/text.asp?2020/17/1/7/285466


Full Text



 Introduction



Conjunctiva is a transparent membrane lining the inner surface of the eyelids and the globe up to the corneoscleral limbus and has a dense lymphatic supply.[1] Part of the conjunctiva is visible and hence exposed to sunlight; lesions in this area tend to the present early.[2] Tumours could originate from the eye or structures in the orbit such as the lacrimal gland and nerves. They could also be metastatic originating from other structures distant from the orbit.

Depending on the melanin elaboration, conjunctival lesions could be melanocytic or non-melanocytic.[3] In general, conjunctival lesions could be classified as neoplastic or non-neoplastic, such as pinguecula and pterygium, whereas neoplastic lesions can be further divided into benign-like papilloma and malignant-like squamous cell carcinoma. Pre-malignant lesions include dysplasia and carcinoma insitu. These lesions can be distinguished based on the patient's history, clinical presentation and histopathological features.[4]

Conjunctiva is a common site for the growth of lesions in the eye. A study in Thailand [5] found conjunctival lesions to be the most common lesions in the eye and adnexa. Another study in Lagos showed that conjunctival lesions are the most common of all orbito-ocular lesions, with conjunctival squamous cell carcinoma as the most common malignant conjunctival lesion.[6] Ocular surface squamous neoplasia (OSSN) is a term that involves pre-malignant and malignant conjunctival lesions, ranging from dysplasia to invasive tumour that could lead to intraorbital or intracranial extension.[7] With the advent of the human immunodeficiency virus (HIV)/AIDS pandemic, there was an increased incidence of OSSN.[7] A study in Nigeria found OSSN to account for 12% of all eye lesions.[8] The increase in the incidence of OSSN may be a result of interplay of some risk factors such as-HIV infection, co-infection with human papillomavirus (HPV) and exposure to sunlight (ultraviolent radiation).[7]

The aim of this study was to determine the pattern of excised of conjunctival lesions over a 6-year period.

 Materials and Methods



This was a 6-year (2010–2015) hospital-based retrospective study, involving the retrieval of records, paraffin blocks, and glass slides of all histologically diagnosed conjunctival lesions at the pathology department of our hospital which is a referral centre.

The Pathology Laboratory of Aminu Kano Teaching Hospital receives biopsy specimens from the tertiary eye facilities and general hospitals from Kano and neighbouring states. Histology sections were made from biopsies fixed in formalin and embedded in paraffin, which were then stained with haematoxylin and eosin stains.

 Results



A total of 198 conjunctival lesions were diagnosed in the histopathology laboratory during the study. This includes local and referred cases from other hospitals.

There were 136 (68.70%) male and 62 (31.30%) female patients with male-to-female ratio of 2.2:1. Their ages ranged from 1 to 87 years. The mean age was 37.69 ± 16.39 years; while the mean ages of the males and females were 39.91 ± 15.88 and 32.85 ± 16.59 years, respectively. About 92 (46.50%) and 62 (31.30%) of the conjunctival lesions were within the age groups of 21–40 and 41–60 years, respectively [Table 1].{Table 1}

Frequencies of the 19 different conjunctival lesions diagnosed during the study are shown in [Table 2]. The most common lesions observed were conjunctival squamous cell carcinoma 50 (25.30%), dysplasia 46 (23.20%) and squamous papilloma 24 (12.10%) [Figure 1], [Figure 2], [Figure 3]. OSSN comprises about 55.6% of the lesions.{Table 2}{Figure 1}{Figure 2}{Figure 3}

The conjunctival lesions were also diagnosed based on the neoplastic nature, which was classified into malignant, pre-malignant and benign lesions; with 54 (27.3%) being malignant, 61 (30.8%) pre-malignant and 83 (41.9%) benign. Compared with age grouping, majority of the malignant, pre-malignant and benign lesions occurred more within the age groups of 41–60 and 21–40 years, respectively. Benign lesions are more in both gender 81 (41.9%) [Table 3] and [Figure 4].{Table 3}{Figure 4}

There was no statistically significant correlation between the type of conjunctival lesions and age and sex with the Pearson's Chi-square test (P > 0.029 and P > 0.010). There was no statistically significant relationship between neoplastic nature (malignant, pre-malignant and benign lesions) and gender (P > 0.928). However, there is a statistically significant correlation between neoplastic nature and age (P < 0.003).

 Discussion



Conjunctival lesions are frequently seen in the eye clinic because the conjunctiva is a lining of the eye and hence visible; patients notice any change or growth in this area early.

Conjunctival lesions are among the most important causes of ocular morbidity for which early detection and pathological diagnosis are crucial for proper management and hence outcomes. Conjunctival neoplasms could arise primarily from the conjunctiva or spread from contiguous anatomic structures such as paranasal sinuses and nasopharynx or metastases from distant structures. The histopathologic characteristics of these tumours are crucial to their biologic behaviour and the line of management.

There was a male preponderance in this study (the males have almost doubled the females), which is in keeping with studies from Jos and another study on ocular tumours in the same area.[9],[10] This may be a reflection of the health-seeking behaviour in the community. Most of the lesions occurred during the (adult life) active stage of life, this may be due to constant exposure or interaction of the conjunctiva with some environmental factors such as ultraviolet radiation depending on the geographical location and the occupation of an individual during his/her lifetime. Other risk factors may have preponderance in this age group such as infection with HIV and HPV.

Studies have documented that decrease ultraviolet radiation is associated with an increase in latitude. A study by Newton et al. found that the incidence of OSSN decreased by 49% for each 10° increase in latitude (P< 0.0001) from >12 cases/million/year in Uganda (latitude 0°) to <0.2 cases/million/year in the United Kingdom at latitude >50°.[11] Another study documented a 29% decrease in the incidence of conjunctival squamous cell carcinoma per unit reduction in ultraviolet exposure (P[7]

A study in Nigeria noted OSSN to be 12% of conjunctival lesions which is much lower than that noted in our study, which may be attributable to environmental factors.[8] Similar prevalence is noted in a study conducted in Zimbabwe.[12] A study in the sub-Saharan Africa reported that OSSN is seen in 4%–8% of patients with HIV infection.[13] The increasing incidence of OSSN in sub-Saharan Africa was thought to be due to some associated risk factors, namely HIV and HPV infection and exposure to the UV radiation.

There is a preponderance of benign lesions in this study which is comparable with studies by Bastola et al. and Ud-Din et al,[14],[15] but in contrast to a study in the same area, which found a preponderance of malignant lesions.[16] This contradiction may be due to patients increased awareness on the importance of histology of excised lesions. There is a statistically significant association between sex and neoplastic nature.

The most common benign lesion was squamous papilloma which is most common in adults which is in keeping with studies done by Farabi [17] and Umar et al[16] from the same area; this may be because patients are predisposed to similar environmental conditions and hence risk factors. This is in contrast to a study in Jos [9] which documented pterygium to be the most common benign excised conjunctival lesion, this contradiction may be because our study is carried on excised specimens, and most pterygia excision is carried by paramedical staff and hence not taken to the histology laboratory. The most common malignant conjunctival lesion is conjunctival squamous cell carcinoma, which is comparable to studies in the same area.[10],[16]

The strength of the study is the long duration with a big sample size, hence the results being more reliable. The major limitation of this study is being a hospital-based study, and hence, inferences cannot be generalized to the public.

This study is an eye-opener on the importance of counselling patients for histology because what may seem to be a benign lesion could turn out to be otherwise which will change the outcome of management. There is a need for more research in the future that will correlate clinical findings, investigation results with histological diagnoses of conjunctival lesions. Another aspect that can be looked into is the association of HPV/HIV infection with conjunctival lesions in this environment.

Depending on the presumptive diagnosis, size and extent of the conjunctival lesion, management can consist of serial observation, incisional biopsy, excisional biopsy, cryotherapy, chemotherapy, radiotherapy, modified enucleation, orbital exenteration or various combinations of these methods.

 Conclusion



Conjunctival lesions are more prevalent among males and statistically correlated with age. Benign lesions are the most common conjunctival lesions, whereas squamous papilloma and squamous cell carcinoma are the most common benign and malignant lesions, respectively.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

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