Cytology Services Utilisation Pattern in North-Central Nigeria

Context: Cytology is a simple, fast, low cost, minimally invasive and sensitive technique for evaluating cells sampled from lesions in the body. It is an aspect of pathology service at its fledgling stage in most institutions in sub-Saharan respectively. The sites of other less commonly requested cytology samples in this study included the liver, nose, eyes, testes, urine and peritoneal fluids. The patients’ age ranged from 14 months to 80 years. Conclusions: This study shows a still very low utilisation of cytology services in management of patients. There remains the need of developing diagnostic cytology services in Nigeria, taking advantage of its low cost, accuracy and timeliness as a simple, yet highly useful diagnostic tool in a resource deficient environment.


INTRODUCTION
Cytology is a simple investigative technique for direct visualisation of morphological changes in cells at high magnifications. The accuracy, sensitivity and specificity of this technique is established in medical literature [1]. Cytology also has the peculiar advantages of minimal invasiveness, low cost and speed [2]. The specimen consist of excoriated or passively exfoliated cells, fine needle aspiration smears and lesion imprints [1,3].
The first full-length publication on the use of cytology in Nigeria was written by Bhursnamath et al in 1986 and since then many institutions have adopted it as a component of pathology practice [4,5]. However, cytology practice has been restricted mainly to the tertiary institutions [2]. This present study aimed to explore the scope of employment of cytology in the management of patients in our institution based on the pattern of the requests and samples received in the pathology laboratory.

MATERIALS AND METHODS
This is a retrospective study and the materials consisted of the archival records and slides of the cytology specimens obtained in the histopathology laboratory of the Benue State University Teaching Hospital, Markurdi, Nigeria, from January 2013 to December 2015 inclusive. The hospital has a 350 -bed capacity and serves the communities around Makurdi, including referrals from distant parts of the north -central region of Nigeria. The records and glass slides of cytology specimens reported during the study period were retrieved and analysed. In some instances, faded glass slides were re-stained, evaluated and re-classified using current classification schemes. Cervical cytology specimen samples were collected from the uterine cervix of female patients using Rovers Cervix brush (Rovers Medical Devices B.V., Netherlands), preserved in Specimen Preservative (LGM International Inc, Melbourne, USA), subjected to liquid based processing and the smears obtained were stained using the standard Papanicolaou staining procedure. Fine needle aspiration was performed by passing a small bore needle (21G or 22G) into a swelling or site of the lesion and tissue fluid containing cells were drawn in the hub of the needle using negative pressure created by using a 5ml or 10 ml syringe. A smear was made on a clean glass slide from the aspirate and immediately fixed in 95% ethanol. The fine needle aspirates, fluids obtained from body cavities and exfoliated cell sample smears were stained with Papanicolau or hematoxylin and eosin stains routinely.
Only specimens that met standard adequacy criteria for cytology were included. Such criteria included adequate cellularity; and blood cells, dirt or inflammatory cells not significantly obscuring epithelial cells. All those with incomplete or defective records and those in which a diagnosis could not be rendered because of technical defects, poor quality or evaluation errors, were excluded from the analysis. The local research ethics committee of the institution granted ethical clearance for this work. In addition, the data were analyzed with the Microsoft Excel 2007 edition statistical package.

RESULTS
Cytology samples consisted of 775 (27.5%) out of a total 2,823 specimens accessioned during the three years period giving a histology-tocytology ratio of 2.6:1. Table 1 shows the temporal trends of both cytology and tissue histology specimens during the study period. The overall cytology requests declined as opposed to a rise in histology (Table 1) during this time. A drop of 47.3% in the cytology samples followed an initial 35.6% increase from 273 to a peak of 299 samples. The nature of specimen and organ site distribution of the cytology specimens show that most of the samples were cervical smears constituting 56.3% and with an annual rate of 218 samples per year. There were 291 (37.5%) fine needle aspiration (FNA) biopsies with a rate of 97 cases per year, and 48 (6.2%) exfoliative cytology specimens (pleural fluid, urine, sputum, etc) with a case rate of 16 per year. Further analysis showed 134 (17.3%), 48 (6.2%), 40 (5.2%) and 37 (4.8%) breast, lymph node, soft tissue and thyroid FNAs respectively (Table 2).

DISCUSSION
A total number of 2,823 samples in the three years period attest to the fledgling phase of growth of pathology service in this region. The cytology specimens made up less than one third (775, 27.5%) while histology constituted the bulk (2048, 72.5%). Repeated industrial strike action by health care workers with attendant interruptions of clinical services and some other local factors are some of the reasons probably responsible for the 47.3% drop in the cytology samples observed during the period under review.
Cervical smear samples for screening of uterine cervix cancer screening constituted the bulk (56.3%, 436) of the samples received. Utoo et al (2013) surveyed 172 women in Makurdi and found that only seven percent (12) has had cervical cancer screening [6]. Thus, even though cervical smear constituted the bulk of the specimens, the awareness and utilisation of this diagnostic modality is still below expectations. The "Pap" uterine cervix cancer-screening test is simple to perform and does not require elaborate equipment. A spatula or brush is used to scrape cells off the surface of the uterine cervix, a smear is made on a glass slide, and stained with the Papanicolaou stain [7]. The reasons adduced for the very low utilisation of the Pap test include ignorance, absence of screening centres and physicians' non-recommendation [8]. Cytologic screening programs have led to a large decline in cervical cancer incidence and mortality in developed countries [9]. However, the scourge of this malignancy remains largely high in sub-Sahara Africa communities because of ineffective or absent screening [10]. The literature is fraught with several papers written on this subject [6,8,11].
The rate of 97 fine needle aspiration biopsies per year we observed in this analysis is much below the average 307 FNA per year in most institutions reported by Malami (2008) in a nationwide survey of FNA practice in Nigeria [12]. Fine needle aspiration (FNA) of palpable breast lesions is one of the components of the "triple" test; the other components consisting of palpation and mammography. In our study, fine needle aspiration (FNA) biopsy of the breast was the second commonly requested cytology test, constituting 17.3% (134) and an annual rate of 67 cases per year (Table 2). This is comparable to the 78.5 breast FNAs per year reported by Mohammed et al (2005) in Kano [13]. In Kano, the rate of utilisation of FNA services in patient management steadily grew over the years. Less than ten years later, another author, Yusuf et al (2015), observed a 196% increase to 232. 4 FNAs per year [14]. This figure is over 245% higher than our present findings in Makurdi. Kachewar (2015) recorded an annual rate of 112.5 FNA cases in a rural general hospital in India, a figure almost twice what we obtained in this study [15]. The higher rate of cytology requests in Kano and other places is probably because of increased awareness among surgeons and other clinicians, of the diagnostic usefulness of fine needle aspiration as a quick, cheap, less traumatic and accurate technique. The literature shows that the use of fine needle aspiration to investigate palpable breast lesions has proved over time to be profound with overall sensitivity ranging from 80 -100% and specificity of over 90%. On this basis, unnecessary surgical procedures, sometimes, may be avoided when cytology is quickly employed to confirm clinically suspected cancers [16]. Quite often, the surgeon has to decide whether to request for fine needle aspiration or perform a needle core biopsy. On the side of the pathologist, a high frequency of grey zone diagnosis such as "atypical" or "indeterminate" undermines the usefulness of this test. Correlation of fine needle aspiration with follow-up tissue histology is expected to improve experience of the pathologist, confidence of the surgeons on the cytology reports delivered and judicious selection of the tests to request [2].
Fine needle aspiration of lymph nodes has also been found useful in ascertaining the cause of lymph node enlargements [17,18,19]. Aspiration FNAs per year. FNA is has also been found to be especially useful for quickly investigating other superficial swellings due to conditions such as Burkitt lymphoma and rhabdomyosarcoma in children [20,21].
The thyroid gland is one of the most easily accessible superficial organs. This study recorded 18.5 thyroid FNAs per year (Table 2). This is very low when compared to 163.5 and 63.5 thyroid FNA cases per year in Islamabad and Karachi respectively, both in Pakistan [22,23]; and 194 cases per year in India [24].
Pleural effusions, ascitic fluid, and urine consisted of 4%, 0.5% and 0.5% respectively, of the specimens received. Cytological observations of cells exfoliated in urine grants a reliable diagnostic modality for primary diagnosis and follow-up of patients with neoplastic lesions of the urinary tract [25,26]. There were three buccal smear cytology requests as part of the investigations of sex differentiation anomalies.
Cytology is cheap and highly recommended in resource deficient climes such as obtains in most of sub-Saharan Africa. In Nigeria, the cost of fine needle aspiration biopsy is much less than that of an open or needle core biopsy although variations exist across institutions [27,28]. The procedure is simple and requires no sophisticated equipment except where image guidance is required. The only instrument peculiar to FNA biopsy procedure, for instance, is probably the syringe holder or gun. And although this may enhance the physical convenience of the operator, the use of this instrument has not even been shown to contribute significantly to the yield or accuracy of results [29].
The practice of cytology as a sub-specialty of pathology is still in its early developmental stage in Nigeria. Increasing awareness of its usefulness amongst clinicians, an institutional will to establish dedicated cytology clinics, a structured cytopathology training and increasing experience by pathologists are factors which will engender a key transformative paradigm shift in the practice of cytology in Nigeria [21].

CONCLUSION
In the north -central region of Nigeria, cytology is still grossly under-utilized as a diagnostic tool in the management of patients. Although mostly employed in routine cervical cancer screening, other patients need to benefit more from this simple, minimally invasive, cheap, highly sensitive and accurate investigative modality.

CONSENT
It is not applicable.