Okoshi Kae, Mizumoto Masaki, Kinoshita Koichi
Department of Surgery, The Japan Baptist Hospital, 47 Yamanomoto-cho, Kitashirakawa, Sakyo-ku, Kyoto, 606-8273, Japan.
J Med Case Rep. 2017 Dec 21;11(1):354. doi: 10.1186/s13256-017-1522-x.
The canal of Nuck is an embryological vestige of the processus vaginalis, and presents a potential site for endometriosis seeding. Hydroceles in this region are a rare cause of inguinal swelling in females. In addition, endometriosis localized to the canal of Nuck is exceedingly rare.
A 44-year-old Japanese woman presented with a painful mass overlying her right pubis. She underwent surgery to completely excise the mass. During surgery, division of the external oblique aponeurosis revealed a cyst that occupied the inguinal canal and it adhered to the transverse fascia, inguinal ligament, and pubic bone. The cyst was dissected from the round ligament, and the defect in the internal inguinal ring was repaired and reinforced with mesh. On macroscopic examination, the cyst had a heterogeneous fibrous aspect with dark brown inclusions. Microscopic examination revealed that the cyst was tortuous, lined by mesothelial-like cells, and accompanied by partial subcapsular hemorrhage. Endometrium-like tissue was observed in the cystic wall. Immunohistochemical staining for podoplanin confirmed the mesothelial origin of the cyst-lining cells. The epithelial cells and stromal cells were positive for estrogen receptors.
In this case of an endometriosis-associated hydrocele of the canal of Nuck, the mesothelial origin of the cyst-lining cells and endometriosis were confirmed by positive immunohistochemical staining for podoplanin and estrogen receptors, respectively. We determined that hydrocele resection and reinforcement of the anterior inguinal canal wall (if necessary) are appropriate treatments for this condition.
Nuck管是鞘突的胚胎遗迹，是子宫内膜异位症种植的潜在部位。该区域的鞘膜积液是女性腹股沟肿胀的罕见原因。此外，局限于Nuck管的子宫内膜异位症极为罕见。
一名44岁日本女性，右耻骨上方出现疼痛性肿块。她接受了手术以完全切除肿块。手术过程中，切开腹外斜肌腱膜后发现一个囊肿占据腹股沟管，且与腹横筋膜、腹股沟韧带和耻骨粘连。将囊肿从圆韧带分离，并用补片修复和加强腹股沟内环的缺损。大体检查显示，囊肿呈异质性纤维外观，伴有深褐色内含物。显微镜检查发现囊肿呈迂曲状，内衬间皮样细胞，伴有部分包膜下出血。囊壁可见子宫内膜样组织。对足板蛋白进行免疫组织化学染色证实囊肿内衬细胞来源于间皮。上皮细胞和基质细胞雌激素受体呈阳性。
在本例Nuck管子宫内膜异位症相关鞘膜积液中，分别通过对足板蛋白和雌激素受体进行免疫组织化学染色阳性，证实了囊肿内衬细胞的间皮来源和子宫内膜异位症。我们确定鞘膜积液切除术和腹股沟管前壁加强术（如有必要）是治疗这种情况的合适方法。
