Background: Basal cell carcinoma (BCC) is a frequently diagnosed skin cancer with variable histopathological types. BCC was not widely studied in Sudan as it is in the Caucasian population. Objectives: To appraise the clinical and histopathological aspects of BCC of the skin in Sudan. Materials and methods: A retrospective descriptive analysis of 84 histologically diagnosed BCC specimens seen at three hospitals in four-year duration were reviewed and classified into histological variants according to the WHO classification 2006. Data were analyzed using Statistical Package for the Social Sciences, version 23.0. Results: The mean age (±SD) of the study participants was 56 (±1.75) years, ranging from 20 to 92 years and 63.1% were females (Female to male ratio 1.7:1). The most common incidence was among the age group 51 - 60 years. The face was the primary tumor site in 89.3% with a predilection for the nasal area (31% of those in the face), followed by the trunk (6%). Out of the total, 54.8% were histologically categorized as nodular/solid, while infiltrative accounts for 11.9% followed by the superficial type (8.3%). Surgical margins were involved in 34.5% of cases and peri-neural invasion was seen in 3.6% of cases, mostly were of the infiltrative variant. Conclusion: BCC in Sudan is commonly present in the head as solid nodular histopathological variant which is correlated with worldwide distribution but has slightly younger age and female predominance; thus further studies are needed to assess risk factors in Sudanese patients and improve approaches for earlier diagnosis and better management.
Basal cell carcinoma (BCC) is a commonly diagnosed skin cancer representing 70% of skin cancers and originating from the basal layer of the epidermis and its appendages [
The greatest proportions of skin cancer are encountered in regions with high quantities of ultra violet (UV) radiation such as South Africa and Australia [
Generally, men are known to be affected twice as often as women. This could be attributed to increased work-related exposure to the sun, though these dissimilarities are becoming less significant with changes in lifestyle. The reported male to female ratio is about 2.1:1 [
BCC has different clinical presentations including shining papules with noticeable subepidermal blood vessels, ulcerative lesion, nodules and pigmented lesion [
Although BCC is seen in people of all ethnicities and skin kinds, dark-skinned persons are rarely affected. It is most often found in light-skinned individuals, yet there are marked ethnic and geographical variability. Genetic predisposition and UV exposure are considered important predisposing factors for BCC [
In Sudan, there is difficulty in estimating incidence of BCC because it is usually not included in cancer registry statistics. There are a few published studies about it recently. BCC represented (14.9%) of superficial skin cancers in Sudan in a remote study done on 1972 [
This study mainly focused on clinical presentation and histopathological patterns of BCC among Sudanese population comparing it with worldwide distribution.
This descriptive cross-sectional study was conducted in three main pathology centers in Khartoum State, Sudan, namely the National Health Laboratory (NHL) which a reference laboratory, Omdurman Teaching Hospital (OTH) (A tertiary hospital) and Soba University Hospital (SUH) that a tertiary hospital belongs to Khartoum University, in four years’ duration (from the first of January 2010 to the 31 of December 2013).
This study included all patients diagnosed histologically as basal cell carcinoma at the Histopathology Departments of (NHL), (OTH) and (SUH) during the study period with adequate records and histological slides or paraffin wax embedded blocks. Cases with deficient records missed request forms or missed histopathology slides or paraffin wax embedded blocks were excluded. All BCC cases diagnosed histologically in the three study areas during the study period were potential subjects to be included in this study (97 cases). Eighty-four of them fulfilled the inclusion criteria.
A predesigned questionnaire was filled by the first author. Variable includes age, gender, site, margins, histological variants and clinical information.
From paraffin embedded blocks thin histological sections were obtained and stained with Hematoxylin and eosin (H & E) stain, then examined under light microscopy by the two authors. BCC cases were classified into histological variants according to WHO classification 2006 [
The collected data were analyzed by Statistical Package for the Social Sciences (SPSS) (IBM, USA) analytical system version 23.0. Descriptive statistics and Chi squire test were used. P value at less than 0.05 was considered significant.
The study was approved by the Ethics Committee of MD Pathology-Khartoum University. Permission to conduct the study was taken from the directors of the three study areas.
During the four years of the study period, the total number of cases diagnosed as basal cell carcinoma in the three centers was 97 cases, of which 13 cases were excluded. Eighty-four cases were included in this study.
In this study, the age of patients ranged from 20 to 92 years with a mean age (±SD) of 56 (±1.75) years. The most common incidence was among the age group 51 - 60 years 40 (46.4%) and 13 (15.5%) were >70 years.
Regarding gender distribution 53 cases (63.1%) were females and 31 cases (36.9%) were males with a female to male ratio 1.7:1.
Total percentage of females <50 years was 21 (39.6%) while males in this age group were 10 (32.3%) (
Distribution of primary sites involved is shown in (
Age Groups | Gender | ||
---|---|---|---|
Male % Count within gender | Female % Count within gender | Total % Count within gender | |
20 - 50 | 10 32.3% | 21 39.6% | 31 36.9% |
51 - 70 | 15 48.4% | 25 47.2% | 40 47.6% |
>70 | 6 19.4% | 7 13.2% | 13 15.5% |
Total | 31 100.0% | 53 100.0% | 84 100.0% |
Concerning histopathological variants (
The histological characteristics of basal cell carcinoma; the peripheral palisading (
Distribution of different histological variants among body sites although statistically insignificant (P-value 0.08) shows that the superficial variant (33.3%), infundibulocystic (25%) and basosquamous (75%) mainly located in the trunk, while in the face all the variants were represented.
About one third of basal cell carcinoma cases were histologically pigmented while 64.3% did not show obvious pigmentation.
The margin was involved in 34.5% while it was free in about 36.9% of the cases. Variable histological variants show difference regarding margin involvement although insignificant (P-value = 0.23); it represented 32% of nodular solid, 55.6% of infiltrative, 50% of morpheaform, 50% of basosquamous and 100% of the micronodular variant. The peri-neural invasion was seen in 3.6% of cases, mostly were of the infiltrative variant. Regarding clinical information 4.8% of cases show the history of recurrence and 2.4% were known cases of Albinism. One case (1.2%) was clinically diagnosed as Xeroderma pigmentosa.
Basal cell carcinoma is the most frequently diagnosed skin cancer globally [
In the present study nearly 37% of all reported cases are below 50 years and the mean age is 56 years indicating that basal cell carcinoma tends to appear in younger age than what is reported in the literature when comparing it with other studies in Sudan, Egypt, Tunisia, Nigeria, South Africa and worldwide studies in Europe and USA [
The frequency of basal cell carcinoma in men and women is different with a female preponderance in this study, unlike other studies which show male predominance [
Basal cell carcinoma occurs mainly in the sun exposed regions predominantly involving the face. The majority (89.3%) of cases were excised from the face in this study with the nose comprising (31%) of those in the face. Other sites include the trunk (6%) and lower limbs (4.8%). This is comparable to what was reported in the literature [
The most common histopathological pattern in this study was the nodular/ solid variant which is correlated with worldwide distribution, while infiltrative represents 11.9%, followed by superficial variant (8.3%) and other variants constitute lesser frequencies. This is comparable to published studies, one in the British Journal of Dermatology showing 78.7% of cases were nodular, 15.1% were superficial and 6.2% were morpheaform [
Many studies classify BCC as a low risk group and high risk according to biologic behavior that is to say; local recurrence, local destruction and peri-neural invasion [
The BCC subgroup of the European Dermatology Forum (EDF)’s Guidelines Committee recognized three major clinical types of BCC (nodular, superficial and morpheaform), four histological subtypes (superficial, nodular, infiltrative and morpheaform), three prognosis groups (high, intermediate and low risk) and proposed therapeutic strategies that guide dermatologist for better individualized management of BCC [
Knowledge of site and margin involvement drives management. For facial lesions, “Mohs” surgery is the treatment of choice. Margin assessment whether with frozen or permanent sections is critical for large and infiltrative lesions. Radiation therapy is also an option for patients reluctant or unable to undergo surgery or in the case of positive margins or extensive peri-neural invasion [
In this study, the peri-neural invasion was associated with aggressive histopathological variants mainly the infiltrative pattern (3.6%); a finding that is comparable with other studies [
For reporting of biopsies, the essential task for the pathologist is to diagnose the presence or absence of a BCC. However, some clinicians may request subtyping of BCC. Knowledge of the subtype may be helpful, for example, for a “Mohs” surgeon to have a visual image of what to expect on frozen sections, especially if the slides of the prior biopsy are available. On shave or cauterization excisions, it is also helpful to comment on the margin status. Otherwise, patients with a small BCC may undergo unnecessary subsequent excisions for tumors which were already completely removed by the initial biopsy [
In the current study, about 35.7% of cases were pigmented while 64.3% did not show obvious pigmentation. Some studies show that microscopic presence of melanin could be present in clinically pigmented and non-pigmented BCC [
Basal cell carcinoma is correlated with certain inheritance or familial diseases and this occurs in a younger age group [
One of the limitations of this study is that supplementary studies such as immunohistochemistry and molecular techniques were not used to confirm the diagnosis of these BCCs. Though the histological diagnosis of BCC is usually straightforward, however, problems can arise from histological overlap with other basaloid epithelial neoplasm and from insufficient histological sampling [
Basal cell carcinomas may collide with a number of epithelial and nonepithelial tumors. Common associations include BCC and seborrheic keratosis or BCC and melanocytic nevus. Immunohistochemistry may occasionally be helpful to differentiate BCC from histological mimics thereof. Basal cell carcinomas are typically immunoreactive for 34BE12, MNF116, and Berep4 which are epithelial markers. They are usually negative with Cam5.2, AE1: AE3, EMA and cytokeratin (CK)7 [
Focal labeling with AE1: AE3 may be seen in the squamatized portion of a BCC. Immunoreactivity with Cam5.2 or anti-CK7 may be found when eccrine ducts are entrapped by BCC or in BCCs with focal eccrine differentiation. Basal cell carcinomas are negative for CK20, but a subset of BCCs is (usually only weakly) positive for chromogranin and/or synaptophysin [
BCC in Sudan is commonly present in the head as solid nodular histopathological variant which is correlated with worldwide distribution but has slightly younger age and female predominance. We noticed that peri-neural invasion is associated with aggressive histopathological variant mainly the infiltrative pattern. Different histopathological types of basal cell carcinoma are important to be included in the report because it reflects variable biological behavior. The clinicopathological correlation and professional assessment of BCC to improve approaches for earlier diagnosis and management are recommended. Further researches regarding BCC and its predisposing factors in Sudan are recommended.
Thanks to all the working staff at the National Health Laboratory, Omdurman Teaching Hospital and Soba University Hospital for facilitating the conduct of this study.
Sulieman, T.M.E. and Husain, N.E. (2017) Clinicopathological Pattern of Basal Cell Carcinoma among Sudanese Patients. Open Journal of Pathology, 7, 67-79. https://doi.org/10.4236/ojpathology.2017.74007