Periurethral mass in women is an uncommon diagnosis, which is a challenge to the medical professionals due to the nonspecific clinical presentation and a broad differential diagnosis. Urethral diverticulum is the most common pathology (84%), whereas vaginal cyst (6%) and leiomyoma (7%) comprise the majority of the remaining pathologies [1]. Most of the periurethral lesions are benign and malignant lesions are extremely rare. Although the risk of malignancy is small, differentiating between benign and malignant lesions is important for management and surveillance. Imaging techniques including MRI and CT can provide useful information to aid diagnosis [5]. when a preliminary diagnosis cannot be made based on physical examination and radiologic studies, biopsy should be performed.

Intestinal-type adenocarcinomas are aggressive malignancies which are most frequently localized in in the sinonasal tract. To our knowledge, this is the first reported case of intestinal-type adenocarcinoma arising in the periurethral region. In present case, immunohistochemical stains showed positive reaction for CK20 and CDX2, supporting the diagnosis of intestinal-type adenocarcinoma. As the tumor mimic the appearances of carcinomas or adenomas of intestinal origin, extensive research including gastrointestinal tract fiberscope, cystoscopy and CT scan should be performed to rule out the primary colorectal adenocarcinoma.

Due to the rarity of this tumor, there is no data in literature regarding strategy for their optimal treatment. As Intestinal-type adenocarcinomas behave as high-grade malignancies [4], radical cystourethrectomy with a wide resection of the paraurethral tissue and anterior vaginal wall, may offer superior local control. In this case, the patient refused radical cystourethrectomy and received surgical resection of the periurethral mass with entire urethra and part of the anterior vagina wall. Since the distal end of the mass is firmly adjacent to the vaginal wall, transperineal approach may be necessary for the complete excision of the mass. For patients with locally advanced disease, a multimodal therapeutic approach is required. In this case, the palliative chemotherapy was administered to our patient because of positive surgical margin. The inclusion of systemic therapy may offer improvement of local control and reduction of distant metastasis.

In conclusion, we have reported the first case of the primary periurethral adenocarcinoma of intestinal type. There are currently no standardized protocols for the diagnosis, clinical course, and treatment of this rare tumor. This case study can aid decision-making regarding the diagnosis and treatment of this tumor.