Ciliated vulvar cyst in the labia majora: A case report

INTRODUCTION

Vulvar cysts are a unique entity. They can have significant implications for the mental health and well-being of young patients. They require special attention due to their anatomical and physiological characteristics.^1,2 The exact etiology of these vulvar cysts with cilia is yet to be understood. Current research suggests that the most probable origin of these cysts is from the epithelial remnants of the Mullerian ducts. It is widely believed that these result from incomplete involution or fusion abnormalities of the Mullerian ducts during embryogenesis. This incomplete regression can lead to the formation of cystic structures, typically located in the vulvar region.^3,4 Furthermore, hormonal influences also play a role in developing these vulvar ciliary cysts. Changes in hormone levels can also affect the growth and maintenance of these cystic structures. This is especially relevant in young patients, where fluctuations in hormonal levels are common.^5,6

CASE REPORT

We discuss the case of a 21-year-old female who came with a complaint of a moderate-sized cystic swelling localized to the right labia majora [Figure 1a and b]. It was 5-6 cm long and filled with liquid content. The cystic swelling was connected to the skin of the labia majora with a narrow stalk. According to the patient’s history, the cystic swelling appeared 2 years ago and gradually increased in size without causing any particular symptoms. However, due to apprehension, she did not divulge this information to her family. After marriage, she came to the hospital for aesthetic reasons. Her menarche started at the age of 12 years, and she had regular menstrual cycles. On clinical examination, the inguinal region was free of any hernia. Surgical excision was indicated, and she was scheduled for elective removal of the lesion. The patient underwent surgery under spinal anesthesia. She was placed in a lithotomy position, and Foleys catheterization of the bladder was done. A vertical incision was made on the cyst after infiltration of saline below the skin, and the entire cyst was excised up to the level of the stalk-skin attachment. Right labial skin edges were sutured with continuous interlocking suture with 2-0 Vicryl [Figure 2] after excising the extra redundant skin. The patient responded well to the procedure without any complications. The intact cyst was sent for histopathological examination. The cut section of the specimen revealed a unilocular cyst filled with serous fluid. The cyst wall was 2 mm thick. The wall of the cyst was lined by ciliated columnar epthelium [Figure 3]. The final impression showed features of a benign Mullerian cyst. Immunohistochemical (IHC) analysis showed that the ciliated cells were positive for estrogen receptor (ER), progesterone receptor (PR), cytokeratin 7(CK7), PAX8, and WT1, which confirmed the Mullerian origin. No complications were observed postoperatively, and at the 4-week follow-up visit, the patient was in good clinical condition. She was very satisfied with the aesthetic outcome and was psychologically relieved.

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Figure 1: (a) A 5-6 cm long cystic swelling filled with liquid content (blue arrow). (b) This image showed a narrow stalk of cyst (black arrow).

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Figure 2: Postoperative image after cyst excision and suturing shows that normal anatomy is reconstructed.

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Figure 3: (a) H&E stained - low power slide showed cyst lined by ciliated columnar epithelium with underlying fibro-collagenous stroma, (black arrow) (magnification 100x). (b) H&E stained - High power view showed well formed apical cillia and basally located nuclei without atypia, (blue arrow)(magnification 40x), H&E: Hematoxylin and eosin.

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DISCUSSION

Vulvar inclusion cysts are quite ordinary and mostly benign. These consist of Bartholin gland cysts, Canal of Nuck cysts, inclusion cysts of epidermis, mucous-containing cysts, cysts filled with sebaceous material, and noncystic masses like inguinal hernias. However, benign ciliated cysts of the vulva are uncommon and remarkably rare, with only about 10 cases being documented to date.^3,6,7 These ciliated cysts of the vulva are usually discovered by chance in females in their 30s and 40s. This is one of the distinguishing features of this cyst and can be linked to pregnancy or external progesterone use.⁷ The pathogenesis of these types of cysts, is still not clearly understood. Several explanations have been suggested, including Mullerian heterotopy, origin from the urogenital sinus, and ongoing inflammation of the vulvar vestibule.¹

Sima et al.⁸ in 2024 reported a case report of a 13-year-old female who presented with a large, elongated cystic formation, localized on the right labia majora. It was 20 cm long. A cystectomy was performed. Histopathology showed that the cyst was fluid-filled and the cyst wall was lined by a layer of pseudostratified ciliated epithelium. IHC showed that the cells were positive for ERs and PR, cytokeratin 7, PAX8, and WT1, which confirmed Mullerian origin.⁸ The IHC findings were similar to our study, while histopathology report in our study showed ciliated columnar epithelium.

In 2024, Chang S, and Adeyemi-Fowode⁹ reported a 12-year-old female who had recently started menstruating and approached the clinic with a recurrent cyst on the left vulva, which reappeared 20 months after it was removed in another hospital. The cyst was cut along with the attached lateral skin to ensure complete resection without rupture. Pathology revealed that the cyst was lined by nonmucinous ciliated cuboidal and low columnar cells.⁹ The HPR showed similar findings in our case.

In 2020, Ghosh et al.² mentioned a 12-year-old female who attained puberty earlier than the usual age of menarche. She presented with a swelling arising from the labia majora and was diagnosed with a Bartholin cyst. The cyst was excised, but the histopathology reported a ciliated vulvar cyst. To confirm the diagnosis, the cyst lining was subjected to IHC, which showed ER and PR positivity. They concluded that ciliated cysts of the vulva are rare in children but are benign and can be successfully treated.²

Beland et al.¹ in 2018 reported a case of an 11-year-old female who visited a pediatric urologist with a very large cystic structure distorting the introitus, arising under the left labia. Ultrasonographic studies did not demonstrate communication of the cyst with the pelvis. The cyst was excised, and histopathology confirmed a simple ciliated cyst of the vulva.¹ The finding was similar to our case report.

Our case differs from other cases mainly in terms of age.

The treatment of ciliated vulvar cysts is surgical excision, which should be curative and, most importantly, should improve the labial appearance and prevent recurrence. The accurate diagnosis is crucial for prognosis and can be easily confirmed by histopathological examination. In this present case, the tissue showed ciliated columnar epithelium similar to normal Mullerian epithelium, confirming it as a benign ciliated vulvar cyst. Surgical removal of the cyst was both curative and cosmetically restored the appearance of the external genitalia.

CONCLUSION

The most widely accepted idea is that of Mullerian heterotopy, in which paramesonephric duct tissue is misplaced during embryogenesis. It is hormonally sensitive, which could explain the interrelation between ciliogenesis with pregnancy or external progesterone use. The IHC of the vulvar cyst’s lining reveals key clues about where these tissues originate.