|Year : 2023 | Volume
| Issue : 2 | Page : 102-111
Histopathologic profile of cutaneous cystic lesions in teaching hospital, Nnewi, South-east, Nigeria: a 9-year Review
Ifeoma F Ezejiofor1, Olaniyi O Olaofe2, Ogochukwu I Ezejiofor3, Cornelius O Ukah1, Nnamdi S Ozor1, Adeiza S Enesi1, Chukwuemeka N Osonwa1
1 Department of Anatomic Pathology and Forensic Medicine, Nnamdi Azikiwe University, Awka, Nigeria
2 Department of Morbid Anatomy and Forensic Medicine, Obafemi Awolowo University Teaching Hospitals Complex, Osun State, Nigeria
3 Department of Dermatology, Nnamdi Azikiwe University Teaching Hospital (Nauth), Nnewi, Nigeria
|Date of Submission||23-Aug-2022|
|Date of Decision||04-Jan-2023|
|Date of Acceptance||05-Jan-2023|
|Date of Web Publication||25-Apr-2023|
FMCPath, FWACP, MBBS (Benin) Ifeoma F Ezejiofor
Department of Anatomic Pathology and Forensic Medicine, Nnamdi Azikiwe University, Awka 435101
Source of Support: None, Conflict of Interest: None
Background A cyst is an enclosed space or abnormal sac within a tissue, usually containing fluid or semisolid matter and lined by epithelium.
Aims and objectives To study all the cutaneous cystic lesions with respect to age, sex, anatomic site, and histologic types in a population of Nnewi, South-East Nigerian. It also aimed at highlighting the importance of histology in evaluating and preventing misdiagnoses encountered in cutaneous cystic lesions.
Patients and methods A retrospective review was performed on the histopathology register on all histologically diagnosed cutaneous cysts at the Histopathology Department of Nnamdi Azikiwe University Teaching Hospital (NAUTH), Nnewi, Nigeria from 2011 to 2019.
Results A total of 94 cutaneous cystic lesions, accounting for 1.3% (94/7204) of all surgical biopsy specimens, were included in this study. An overall clinicopathological correlation showed 26.6% (25/94) accuracy, but 73.4% were incorrectly diagnosed, with 7.4% (5/69) of cases misdiagnosed clinically as malignant lesions and one case of malignant cystic lesion diagnosed clinically as benign cyst. There were 49 males and 45 females, giving a slight male predominance, with male to female ratio of 1.1 : 1. The age ranged from 6 weeks to 79 years, with a mean±SD age of 26.5±21.1 years, and a peak age group of 0–10 years, representing 29.8% (28/94). Benign cutaneous cystic lesions were far commoner than malignant ones and included majorly epidermal inclusion cyst [37.2% (35/94)], pilar cyst [17.0% (16/94)], thyroglossal cyst [12.8% (12/94)], and dermoid cyst [8.5% (8/94)]. The only malignant cutaneous cyst was immature cystic teratoma [1.06% (1/94)]. The anatomic site most frequently affected was the head and neck [63.8% (60/94)].
Conclusion Histopathologic evaluation is still the gold standard in eliminating misdiagnosis of these lesions. Epidermal inclusion cysts followed by pilar cysts were commonest cutaneous cystic lesions in our environment and occur more at the third decade and above, whereas cystic hygroma, dermoid cysts, and brachial cyst were predominant at the first decade of life.
Keywords: dermoid cyst, epidermal inclusion cyst, misdiagnosis, pilar cyst, South-East Nigeria, thyroglossal cyst
|How to cite this article:|
Ezejiofor IF, Olaofe OO, Ezejiofor OI, Ukah CO, Ozor NS, Enesi AS, Osonwa CN. Histopathologic profile of cutaneous cystic lesions in teaching hospital, Nnewi, South-east, Nigeria: a 9-year Review. Egypt J Dermatol Venerol 2023;43:102-11
|How to cite this URL:|
Ezejiofor IF, Olaofe OO, Ezejiofor OI, Ukah CO, Ozor NS, Enesi AS, Osonwa CN. Histopathologic profile of cutaneous cystic lesions in teaching hospital, Nnewi, South-east, Nigeria: a 9-year Review. Egypt J Dermatol Venerol [serial online] 2023 [cited 2023 May 31];43:102-11. Available from: http://www.ejdv.eg.net/text.asp?2023/43/2/102/374464
| Introduction|| |
Cutaneous cyst poses cosmetic and psychosocial concerns in individuals presenting with the lesion. Many dermatopathologists classify cutaneous cysts in many different ways but mostly on the basis of their pathogenesis or into true and pseudocyst . True cysts are defined as an enclosed space or abnormal sac within a tissue, usually containing fluid or semisolid matter and lined by epithelium, whereas pseudocysts are less common and are defined as cyst-like structures without an epithelial lining . It can also be classified according to their origin by examining the lining of epithelium histologically ,. True cysts are mostly retention cysts and are derived from the dermal appendages or developmental cysts, which are derived from the persistence of vestigial remnants .
Appendageal cysts include epidermal (infundibular or epidermal inclusion) cyst, HPV-related epidermal cysts, proliferating epithelial cysts, tricholemmal (trichilemmal or isthmus-catagen or pilar) cysts, proliferating and malignant tricholemmal cysts, subungual onycholemmal cysts (benign or malignant), hybrid cyst, hair matrix variant of epidermal cyst, cystic panfolliculoma, pigmented follicular cyst, cutaneous keratocyst associated with nevoid basal cell carcinoma syndrome, eruptive vellus hair cysts, steatocystoma multiplex, milia, comedo/comedonal cyst, eccrine hidrocystomas, and apocrine hidrocystoma .
The developmental cysts include bronchogenic cyst, branchial cleft cyst, thyroglossal cyst, thymic cysts, cutaneous ciliated cyst of the lower limbs, vulval mucinous and ciliated cysts, median raphe cyst, dermoid cysts, cystic teratoma of the skin, and omphalomesenteric duct cysts .
Miscellaneous cysts include parasitic cysts, phaeomycotic cyst, digital mucous cyst, mucous cysts, metaplastic synovial cysts, pseudocyst of the auricle, endometriosis, and cutaneous endosalpingiosis .
Lymphatic cysts are cystic hygroma .
Epidermal cysts have an epithelial wall containing a granular layer with lamellar keratinization, indicating an infundibular origin ,. Tricholemmal cysts have an undulating epithelial wall with no granular layer and a compact keratinization, showing an isthmic origin. In steatocystoma, dermoid cyst, and folliculosebaceous hamartoma, the epithelial lining shows a crenulated appearance, which is seen in the sebaceous duct ,. Hidrocystoma shows the characteristic cuboidal epithelial lining of sweat glands with decapitation secretion in its apocrine forms. The hair matrix cyst wall is composed of basaloid cells maturing to squamoid cells, as seen in the normal hair matrix ,. Dermoid cyst is lined by thin layer of ectodermal squamous epithelium, with presences of skin appendages (true dermoid), containing ectodermal, mesodermal, and ectodermal elements. Milia are small cysts lined by several layers of stratified squamous epithelium with central keratinous material and connected to a vellus hair follicle or commonly to eccrine sweat duct ,.
The various histologic types of cutaneous cysts differ in anatomic distributions, age of the patient, and sex predilections. Cutaneous cysts can occur de novo (congenital) or depending on the predisposing lesion, or following traumatic events ,.
Significantly, there is a dearth of information on these lesions in Nnamdi Azikiwe University Teaching Hospital (NAUTH), Nnewi, Nigeria. This study is thus aimed at determining the frequency and morphological patterns of cutaneous cystic lesions in our institution.
| Patients and methods|| |
Nnamdi Azikiwe University Teaching Hospital is a federal teaching hospital located in Nnewi. Nnewi is a major economic hub with many manufacturing companies and one of the three major cities in Anambra State located in the southern part of the state about 22 km South-East of Onitsha. As a referral center, it provides tertiary level health care for patients within Anambra state as well as neighboring cities and states. Anambra state is one of the five South-Eastern states of Nigeria, with a population of 4 055 048 and population density of 840/km2 according to the 2006 census . Its boundaries are formed by Delta state to the west, Imo and River states to the south, Enugu state to the east. and Kogi state to the north. A written informed consent was taken from patients before enrollment in the study.
Ethical approval: ethical approval was obtained from the Ethics Committee, Nnamdi Azikiwe University Teaching, Hospital, Nnewi, Nigeria.
This was a retrospective study that spanned over a 9-year period and involved 94 cases of cutaneous cystic lesions diagnosed in the Histopathology Department of Nnamdi Azikiwe University Teaching Hospital (NAUTH), Nnewi, Nigeria, from January 2011 to December 2019. Laboratory request forms and duplicate copies of histological reports were retrieved, and relevant clinical information and histological type of the lesions were extracted. Only 94 (96.0%) cases had adequate records for inclusion as cutaneous cystic lesions; four (3.9%) cases were excluded from the study owing to inadequate records ranging from unrepresentative tissue, incomplete clinical details of age, and sex. The tissues were initially fixed in 10% formal saline, processed, and embedded in paraffin wax. They were then sectioned and mounted on a glass slide and stained with regular histochemical stain (hematoxylin and eosin). The slides were reviewed by the authors using a multiheaded light microscope (Carl Zeiss MicroImaging GmbH 37081 Gottingen, Germany).
Data were analyzed using the statistics software Statistical Package for the Social Sciences (SPSS) Incorporated (version 21; Chicago, Illinois, USA). Quantitative continuous variables like age were summarized using mean and SD, whereas categorical variables like sex were summarized using percentage. Results were presented in table and charts. Pearson’s χ2 was used to test the association between two categorical variables, and a P value of less than 0.05 was considered statistically significant.
| Results|| |
A total of 94 cutaneous cystic lesions met the criteria for this study in the period under review, accounting for 1.3% (94/7204) of all surgical biopsy specimens. Overall, 26.6% (25/94) of cases were clinically diagnosed accurately but 73.4% of cases did not correlate with the clinical diagnosis. One malignant lesion was misdiagnosed as benign cutaneous cyst clinically, whereas 7.4% (5/69) of cases were clinically misdiagnosed as malignant lesions. Of 94 cutaneous cystic lesions seen in this study, 52.1% (49 cases) were males and 47.9% (45 cases) females, giving a slight male predominance, with male to female ratio of 1.1 : 1. The age ranged from 0.06 (6 weeks) to 79 years, with a mean±SD age of 26.5±21.1 years. Benign cutaneous cystic lesions were far more common, comprising of 98.9% (93 cases), which included epidermal inclusion cyst in 37.2% (35/94) ([Figure 1]), pilar cyst in 17.0% (16/94) ([Figure 2]), thyroglossal cyst in 12.8% (12/94) ([Figure 3]), and dermoid cyst in 8.5% (8/94). Others were branchial cysts in 5.3% (5/94), cystic hygroma in 4.3% (4/94), endometriosis in 3.2% (3/94) ([Figure 4]), and simple (pseudocyst) cyst and ruptured cyst in 2.1% (2/94) each. Cervical thymic cyst, colloid milia ([Figure 5]), mature cystic teratoma ([Figure 6]), omphalomesenteric duct remnant ([Figure 7]), sebaceous cyst, and steatocystoma ([Figure 8]) were present in 1.1% each. Only one case of neoplastic cutaneous cyst was seen 1.1% (one case), which was immature cystic teratoma ([Figure 9]).
|Figure 1 Epidermal inclusion cyst lined by keratinizing stratified squamous epithelium with a well-developed granular cell layer and contain laminated keratin.|
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|Figure 2 Pilar cyst lined by stratified squamous epithelium devoid of granular cell layer and contain compact homogenous keratin.|
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|Figure 3 Thyroglossal cyst lined by keratinizing stratified squamous epithelium surrounded by fibrous tissue.|
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|Figure 4 Endometriosis characterized by presence of endometrial glands and stroma within the umbilical cutaneous tissue.|
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|Figure 5 Clinical picture of milia characterized by presence of small dermal cyst measuring 1–2 mm in diameter on the thigh of an 11-year-old boy.|
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|Figure 6 A mature cystic teratoma characterized by squamous lining epithelium with skin adnexal structures and mature thyroid follicle.|
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|Figure 7 Omphalomesenteric duct remnant characterized by presence of intestinal mucosa containing numerous glands with goblet cells buried within the skin tissue.|
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|Figure 8 Clinical and histologic pictures of steatocystoma multiplex. (a) Multiple cystic lesions ranging from 0.2 to 0.8 cm in their widest diameters. (b) Histologic section shows stratified squamous epithelium covered by an undulating keratin layer and harbors sebaceous gland on its wall.|
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Epidermal inclusion cystic lesions were by far the most common, accounting for 37.2% (35 cases) and 0.49% of all surgical specimens. There was a male predominance, with male to female ratio of 1.2 : 1. Common age group affected with epidermal inclusion cysts was 21–70 years, with 22/35 (62.9%) cases.
Pilar cystic lesion was the second commonest, accounting for 17.0% (16/94). There was a female predominance, with male to female ratio of 1 : 1.7, whereas thyroglossal cyst was the third commonest lesion, with a male predominance and male to female ratio of 2 : 1. Dermoid cyst was the fourth most common and had equal sex predilection ([Table 1]).
|Table 1 Sex and percentage distribution of different cutaneous cystic lesions|
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Most cases of cutaneous cystic lesions in both sexes were seen within the age group 0–10 years (28 cases, 29.8%), with 17 (60.7%) males and 11 (39.3%) females, followed by 21–30 years (20.2%, 19 cases), and the least cases were seen in the age group above 70 years (two cases, 2.1%). There is a female preponderance in younger age groups between 0 and 30 years, whereas 30 years and above had a male predominance. There were equal sex predilections in age groups 41–50, 61–70, and 71–80 years ([Figure 10]).
|Figure 10 Age groups and sex distribution of patients with cutaneous cystic lesions.|
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The peak age distribution for patients with cystic hygroma, dermoid cysts, mature cystic teratoma, and brachial cyst was at the first decade. Thyroglossal cyst peaked at first and second decades of life, whereas both epidermal inclusion and pilar cysts were common at the third decade and above, with 65.7% (23/35) and 93.8% (15/16), respectively ([Table 2]).
|Table 2 Age groups and percentage distribution of different subtypes of cutaneous cystic lesions|
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The anatomic site affected most frequently was the head and neck in 63.8% (60/94), predominantly the neck in 23.4% (22/94), followed by the scalp in 11.7% (11/94) and periorbital in 6.4% (6/94). Epidermal inclusion cysts were the commonest lesion on the head (15/38) followed by the pilar cysts (9/38) and dermoid cysts (8/38), whereas thyroglossal and branchial cysts were the most frequent lesions on the neck with 45.5% (10/22) and 22.7% (5/22), respectively. Dermoid cyst was the most frequent lesion in the periorbital area [50% (3/6)], whereas pilar cysts were the commonest lesion on the scalp [45.5% (5/11)] followed by epidermal inclusion cyst [36.4% (4/11)]. Epidermal inclusion cyst is the commonest cutaneous cysts on the face [40.7% (11/27)] followed by dermoid cyst [25.9% (7/27)] ([Table 3]).
|Table 3 Head and neck distributions of different histopathologic diagnosis of cutaneous cystic lesions|
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Head and neck were far the most common anatomic sites affected by cutaneous cystic lesions [63.8% (60/94)] followed by male genital [8.5% (8/94)], upper limb [5.3% (5/94)], umbilicus [4.3% (4/94)], female genital [3.2% (3/94)], and breast (chest) and gluteal (2.3% each). Epidermal inclusion cyst were also the commonest cutaneous cystic lesions in the male (penile and scrotum in seven of eight) and female (clitoris in three of three cases) genital organs, with 87.5 and 100%, respectively. The commonest cutaneous cystic lesion in the umbilicus and upper extremities were endometriosis in 75% (three of four cases) and pilar cyst in 40% (two of five cases), respectively. Meanwhile in the breast, both epidermal and pilar cyst were seen, as seen in one of two cases ([Table 4]).
|Table 4 General anatomic distributions of different subtypes of cutaneous cystic lesions|
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| Discussion|| |
Cutaneous cyst causes cosmetic and psychosocial concerns in individuals presenting with these lesions. Google scholar and PubMed show paucity of this research in Nigeria with few studies showing only cutaneous cystic lesions of some parts of the body. This study, however, reviewed all cutaneous cystic lesions of the body, and it constituted 1.3% of all surgical specimens in our institution. An overall clinicopathological correlation in this study showed 26.6% (25/94) accuracy in cutaneous cystic lesions, with 73.4% discordance. One (1.1%) case of malignant and 7.4% cases of benign cystic lesions were misdiagnosed clinically as benign and malignant cystic lesions, respectively. These observations were in tandem with a study by Inbasekaran et al.  in a Medical College Hospital, India, who reported 35.2% accurately with 64.8% of cases not correlating with clinical diagnosis and four malignant lesions misdiagnosed as benign cutaneous cyst clinically. However, Kamyab et al.  in the University of Medical Sciences, Iran, and Singh and Dahiya  in a medical college hospital, Uttar Pradesh, India, reported incongruent results of only 19.6 and 8.11%, respectively. Although their correlations were insignificant, histopathologic evaluation is still very important in making diagnosis of these lesions to eliminate misdiagnosis.
A total of 94 cutaneous cystic lesions met the criteria for this study in the period under review. The mean age was 26.5 years, with age ranging from 6 weeks to 79 years. The peak age of cutaneous cystic lesions was in the 0–10-year age group. There was a slight male predilection, with a male to female ratio of 1.1 : 1. The mean age of the patients agreed with a study in Ibadan, Nigeria (27.99±15.26 years) . However, reports from Sokoto North-west Nigeria, India, Korea, and Iran demonstrated higher mean age of 30.1±11.2, 38.66±19.5, 37.8±16.8, and 42 years, respectively ,,. The sex ratio was similar to observations in Iran, Korea, Ibadan, and Sokoto, with 1.3 : 1, 2.8 : 1, 1.8 : 1, and 3 : 1 respectively ,,,. Nonetheless, Inbasekaran et al.  maintained a higher female predominance in their study, with a male : female ratio of 1 : 1.2. Although the aforementioned reports maintained a marked male preponderance, these ratios are quite high compare with our study. This may be attributed to the fact that our study researched in all cutaneous cystic lesions of the body, whereas other studies were in localized part of the skin. Sokoto and Korea studied only cutaneous cystic lesions in the ear, whereas Ibadan limited its study on oro-facial cutaneous cysts ,. Moreover, studies from Iran and India reviewed all mucocutaneous cystic lesions of the body and had slight sex preponderance, similar to the present study ,.
Head and neck were by far the most common anatomic sites for cutaneous cystic lesions [63.8% (60/94)] in this study followed by perineal area (male genital and female genital) in 11.7% (11/94), upper limb in 5.3% (5/94), and umbilicus in 4.3% (4/94). The other locations appear unusual breast, gluteal, and back. Head and neck is the leading anatomic site in most studies; however, various histologic types of cutaneous cysts differ in anatomic distributions, age of the patient, and sex predilections .
Epidermal inclusion cysts were the most frequent cutaneous cystic lesion in this study and occur most frequently between 21 and 70 years, with a male predominance. It constituted 37.2% (35/94) and 0.49% of all surgical specimens. Mohammed and Abdullahib  in Sokoto, North Western Nigeria, reported similar results and stated 87.5% in their study, with most of cases seen at sixth decade and with a female predilection. Two studies from India had similar reports, with epidermal inclusion cysts ranging from 75.1 to 87.5% ,. Moreover, several other studies from Iran, Jordan, Korea, and Fort Worth Texas had similar observation with epidermal inclusion cyst constituting 47.8, 49, 93.3, and 79%, respectively ,,. Al-Khateeb et al.  in Jordan also reported the third decade of life in both epidermal and pilar cyst. However, Cho and Lee  in Korea showed no significant difference in age, sex, and size according to the location. Epidermal inclusion cysts were commonest on the face, constituting 11.7% (11/94), in this study, followed by perineal areas in 10.6% (10/94) (male genital and female genital), and were rare on the breast, gluteal, and back, with one case each. Most studies showed similar observations, as reported by Vaughan and Wisell  and Al-Khateeb et al.  in Jordan. Nonetheless, Inbasekaran et al.  in India reported upper limb as the commonest site in their study, whereas Johnston  in Weedon skin book reported predilection for the trunk, neck, and face.
Pilar cysts were the second commonest cutaneous cystic lesion in this study and occur most frequently between 21 and 60 years of age, with female preponderance. It constituted 17.0% (16/94) and 0.22% of all surgical specimens. It was most frequent on the scalp (5/11), ear (3/4) and upper limb (2/5), constituting 45.5, 75, and 40%, respectively. Al-Khateeb et al.  in Jordan also reported pilar cyst as the second commonest cutaneous cyst and constituted 27%, with 96% seen on the scalp, similar to our study. Moreover, pilar cyst was the second largest in Iran and Fort Worth Texas and constituted 23.8 and 9%, respectively ,. Johnston  in Weedon skin book reported pilar cyst as commonest on the scalp, with female preponderance, similar to our findings.
Thyroglossal cysts were the third commonest cutaneous cystic lesion and most common developmental cysts in this study and occur most frequently in the second and third decades of life with male preponderance. It constituted 12.7% (12/94) and 0.17% of all surgical specimens. It was most frequent in the anterior neck (10/12) and submental (2/12), constituting 83.3 and 16.7%, respectively. Johnston  in Weedon skin book also reported its predilection on the midline of the neck, as found in this study.
Dermoid cyst formed the fourth commonest cutaneous cysts (8/94, 8.5%), with equal sex predilection (female=male) and most frequent in the first decade of life with higher proportions seen on periorbital region (3/6, 50%). Both studies from India and reviews from Korea and Sokoto, North-west Nigeria, reported it as being frequent in the first decade of life but ranked second commonest cutaneous cystic lesion in their studies ,,,.
Branchial cyst was the fifth commonest cutaneous cystic lesions and the second most common developmental cyst. It occurred solely on the lateral side of the neck, whereas cystic hygroma was the only lymphatic cystic lesion in this study, with equal sex predilection, and both were seen more in the first decade of life. These observations were similar to most studies.
| Conclusion|| |
Appendageal cysts were far more common than developmental cyst with epidermal inclusion cyst followed by pilar cyst, being the commonest in our environment. Histopathologic diagnosis is still the gold standard in it management to avoid misdiagnosis.
Special appreciation to Ezeh Ebere. E for her assistance in the data entry for this work. The authors also acknowledge the histopathology laboratory record staff for their assistance in the provision of all necessary records used in the preparation of this work.
Authors’ contributions: This is to certify that the authors contributed to the conception, data collection, analysis, and intellectual contents of this article.
Data availability: The data used to support the findings of this study are available from histopathology laboratory records and laboratory request forms in the Department of Histopathology Nnamdi Azikiwe University Teaching Hospital, Nnewi.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5], [Figure 6], [Figure 7], [Figure 8], [Figure 9], [Figure 10]
[Table 1], [Table 2], [Table 3], [Table 4]