Cutaneous ciliated cyst was described as a painless cyst occurring on the lower limbs of women between the ages of 15 and 30 years. The cysts are typically lined by ciliated cuboidal to columnar epithelium with pseudostratified areas and focal squamous metaplasia is occasionally present. Immunohistochemical studies have demonstrated that the cysts are PR and ER positive, similar to the epithelia of the fallopian tubes. However, outliers of cutaneous ciliated cysts, including those in male patients and in unexpected locations such as the scalp, finger, and scapular area, have been reported. Thus, some hypotheses have been proposed including the Mullerian heterotopias, ciliated metaplasia of eccrine sweat glands, and embryonic remnants of the cloacal membrane. We report a rare case of cutaneous ciliated cyst on the left shoulder of a 7-year-old boy and this is the eighth case of cutaneous ciliated cyst in male patients. Moreover, through reviewing the articles, we try to propose the classification of the cutaneous ciliated cysts into the cutaneous Mullerian cysts and the ciliated cutaneous eccrine cysts.
Cutaneous ciliated cysts are rare benign lesions and are typically lined by a cuboidal to columnar ciliated epithelium, with some areas of pseudostratified ciliated epithelium [
We report a case of a cutaneous ciliated cyst on the shoulder of a 7-year-old boy and propose the classification based on a review of articles describing cutaneous ciliated cysts.
A 7-year-old boy had a 3-year history of a subcutaneous cystic nodule on his left posterior neck area. The lesion was a solitary, painless, soft, and nontender subcutaneous nodule measuring approximately 1 cm in diameter (Figure
Clinical photography of a lesion shows a solitary cyst in the left posterior neck region, 1 cm diameter.
The gross appearance of the lesion indicates a unilocular cyst with brown mucinous contents.
The specimen was stained with hematoxylin-eosin, alcian blue, and periodic acid-Schiff (PAS). Immunohistochemical studies were performed using antibodies to carcinoembryonic antigen (CEA), S-100 protein, ER, PR, epithelial membrane antigen (EMA), and cytokeratins 7 (CK 7) and 20 (CK 20). Microscopically, the cyst wall was lined by stratified columnar epithelia with mucin vacuoles and squamous metaplasia (Figure
The cyst is covered by ciliated columnar epithelium with mucin vacuoles under low-power magnification (40x). (a) Mucin vacuoles are observed with ciliated columnar epithelium (dark blue arrows); hematoxylin and eosin (400x). (b) The inset shows cilia on both the top portion (blue arrow) and the lateral borders (red arrow) of the columnar cells (400x). (c) Squamous metaplasia (400x).
The mucin vacuoles are positive for the periodic acid-Schiff (PAS) and alcian blue stains. (a) Positivity to PAS. (b) Positivity to alcian blue (400x).
(a) The cytokeratin 7 staining is positive in columnar cells but negative for basal cells and squamous metaplastic cells (400x). (b) The immunohistochemical result of carcinoembryonic antigen (CEA) is the opposite (400x).
Cutaneous ciliated cysts are unusual benign lesions. In 1890, Hess first reported a case on the lower back of a 15-year-old girl. Farmer and Helwig later proposed the term cutaneous ciliated cyst for this entity after studying 11 cases in 1978 [
Based on these findings, the Mullerian heterotopia hypothesis was proposed [ Almost all cases arise in female patients. Cutaneous ciliated cysts become apparent after puberty or during pregnancy. Almost all of them are located on the lower limbs. There is no histologic association with adnexal structures in female cases. There are some reports of analogous noncutaneous lesions that are believed to have arisen from Mullerian rest cells. The immunohistochemical staining profiles, including positive staining for ER and PR, are characteristic of the fallopian tube epithelium. Ultrastructurally, the cilia show a 9 + 2 arrangement equal to normal human cilia.
However, outliers of cutaneous ciliated cysts, including those in male patients [
There have been only 8 reported male patients in the 35 reports of cutaneous ciliated cysts. One case occurred on the scrotal skin of a 15-year-old male patient with a history of right cryptorchidism and orchiopexy [
Summary of the reported cutaneous ciliated cysts in male patients. The empty columns mean that the results are not reported.
Age | Site | PAS | SMA | Mucin | S100 | CEA | EMA | ER/PR | CK | Others | |
---|---|---|---|---|---|---|---|---|---|---|---|
Leonforte [ |
42 | Lt. heel | + | − | |||||||
Trotter et al. [ |
28 | Lt. foot | − | − | + | + | |||||
Ashton [ |
25 | Rt. sole | − | − | − | − | + | + | |||
Sidoni and Bucciarelli [ |
60 | Perineal | + | + | + | + | Desmin+ | ||||
Ohba et al. [ |
53 | Rt. cheek | + | + | + | − | + | − | + | Desmin and vimentin− | |
Santos and Mendelsohn [ |
53 | Perineal | + | − | + | − | − | + | + | Vimentin+ | |
Lee et al. [ |
56 | Rt. inguinal | + | + | − | − | + | + | |||
Pérez-Valcárcel et al. [ |
15 | Scrotum | + | + | Cryptorchidism | ||||||
Present case | 7 | Lt. shoulder | + | + | + | − | − | + | − | + |
Our case has some special characteristics compared to the other reported cutaneous ciliated cysts in male patients. The previous male cases were observed in patients from their late 20s to 60s, and no adolescent patients have been reported. Additionally, this is the first male case occurring on the shoulder area and the youngest case. Only one case in a female patient has been reported in the shoulder area [
Some authors have noted that the term cutaneous ciliated cyst is inaccurate and confusing, and they have suggested that cutaneous Mullerian cyst is more preferable [
Written informed consent was obtained from the parents of patient for publication of this case report and any accompanying images. A copy of the written consent is available for review.
The authors declare that there is no conflict of interests regarding the publication of this paper.
Youngjoon Kim analyzed and interpreted the patient data regarding the subcutaneous cyst and the surgical treatment and was a major contributor in writing the paper. Hyunjung Kim performed the histological examination of the cyst and was a major contributor in writing the figure legend and arranging the photos. All authors read and approved the final paper.