Cervical endometriosis mimicking cervical adenocarcinoma: A case report

A 41-year-old woman (gravida 2, para 1) presented with abnormal genital bleeding. Pelvic MRI at her local clinic revealed a 3-cm cervical mass, raising the suspicion of cervical cancer, and she was referred to a tertiary institution. On speculum examination, a polypoid mass protruding into the endocervical canal was observed and a firm mass was palpable in the posterior cervical wall ( Fig. 1 ). Transvaginal ultrasonography revealed a solid hypoechoic mass (44 × 22 mm). MRI demonstrated a poorly demarcated, T2-hyperintense lesion with minute multicystic areas and a focal high T1 signal suggestive of hemorrhage, located in the upper lateral portion of cervical canal, without parametrial or vaginal invasion ( Fig. 2 ). The possibility of solid components within the minute multicystic areas was also considered, which was more suggestive of gastric-type cervical adenocarcinoma than lobular endocervical glandular hyperplasia (LEGH), a benign multicystic lesion typically lined by gastric-type mucinous epithelium. Thickening of the junction zone or pelvic endometriosis was not observed. Diffusion-weighted imaging (DWI) revealed a high signal but no significant apparent diffusion coefficient (ADC) reduction. Positron emission tomography–computed tomography (PET-CT) revealed fluorodeoxyglucose (FDG) uptake in the lesion. Fig. 1 A pelvic examination image. Fig. 1 Fig. 2 Preoperative examination images. Pelvic MRI revealing a poorly defined, T2-hyperintense cervical lesion with minute cystic components and focal high T1 signal suggestive of hemorrhage. No evidence of parametrial or vaginal invasion was observed. DWI showing high signal intensity without significant ADC reduction. PET-CT demonstrating FDG uptake in the lesion. (A-E) MRI images: cervical mass (arrow) (A) T2-weighted sagittal image (B) T1-weighted sagittal image (C) T2-weighted axial image (D) DWI (E) ADC (F) PET-CT image. Fig. 2 A pelvic examination image. Preoperative examination images. Pelvic MRI revealing a poorly defined, T2-hyperintense cervical lesion with minute cystic components and focal high T1 signal suggestive of hemorrhage. No evidence of parametrial or vaginal invasion was observed. DWI showing high signal intensity without significant ADC reduction. PET-CT demonstrating FDG uptake in the lesion. (A-E) MRI images: cervical mass (arrow) (A) T2-weighted sagittal image (B) T1-weighted sagittal image (C) T2-weighted axial image (D) DWI (E) ADC (F) PET-CT image. Cervical cytology and multiple biopsies, including conization and needle biopsy, showed no malignancy or endometriosis. Owing to persistent concerns regarding malignancy, robot-assisted simple hysterectomy was performed. Intraoperatively, the mass was found to have adhered to the right ureter and it extended into the parametrium. Conversion to open surgery was performed due to difficulty in dissecting the right ureter from the mass. The frozen sections of the lesions revealed endometriosis. Accordingly, a hysterectomy was performed, with a portion of the mass left in situ owing to its tight adherence to the ureter. Grossly, a firm, yellowish-white solid mass (approximately 5 cm) with ill-defined margins was located in the right posterior cervix. Histopathology confirmed widespread endometrial glands and stroma within the cervical stroma, consistent with cervical endometriosis, with minimal extension into the lower uterine segment ( Fig. 3 ). Fig. 3 Pathological findings. (A) Gross findings: a firm, yellowish-white solid mass (∼5 cm) with ill-defined margins is located in the right posterior cervix. (B) Hematoxylin and Eosin (HE) staining revealing widespread endometrial glands and stroma within the cervical myometrium, consistent with a diagnosis of cervical endometriosis. Fig. 3 Pathological findings. (A) Gross findings: a firm, yellowish-white solid mass (∼5 cm) with ill-defined margins is located in the right posterior cervix. (B) Hematoxylin and Eosin (HE) staining revealing widespread endometrial glands and stroma within the cervical myometrium, consistent with a diagnosis of cervical endometriosis. The patient recovered uneventfully and was discharged on postoperative day 7. Postoperative oral progesterone therapy was initiated to prevent the progression of endometriosis.

This work did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.

Written informed consent was obtained from the patient for publication of this case report and the accompanying images.

Cervical endometriosis is an uncommon and often underrecognized form of endometriosis typically diagnosed incidentally or after surgical intervention for suspected malignancy [ 1 , 2 ]. It may present with a variety of symptoms, including abnormal genital bleeding, mucoid discharge, or pelvic pain. However, it can also be asymptomatic and discovered during evaluation for other gynecologic conditions. In the present case, endometriosis was not suspected preoperatively. Owing to the imaging findings and clinical course, cervical adenocarcinoma of the gastric type was strongly suspected, and hysterectomy was performed for both diagnostic and therapeutic purposes. However, histopathological examination revealed cervical endometriosis. This suggests that, had the correct diagnosis been established preoperatively, the lesion might have been managed with less invasive medical therapy, such as oral progestins, thereby avoiding the need for extensive surgical intervention. Cervical endometriosis may present as nodular, cystic, or polypoid lesions, occasionally containing hemorrhagic components that exhibit high signal intensity on T1-weighted images, typically surrounded by hypointense cervical stroma on T2-weighted images [ 2 ]. A primary diagnostic concern was the possibility of gastric-type cervical adenocarcinoma. Cervical endometriosis and gastric-type cervical adenocarcinoma can both appear as multicystic cervical masses on MRI, making radiologic differentiation challenging. While gastric-type cervical adenocarcinoma often shows solid components and diffusion restriction, cervical endometriosis typically lacks these features and may present as hemorrhagic cysts with a high T1 signal and elevated ADC values [ [3] , [4] , [5] ]. Histologically, cervical endometriosis is characterized by ectopic endometrial glands and stroma within the cervical smooth muscle, without cytologic atypia or destructive invasion. Although some reports have suggested that needle biopsy may aid in the diagnosis of cervical endometriosis [ 6 , 7 ], a definitive diagnosis was not achieved in the present case despite multiple pathological assessments, including cervical cytology, endocervical curettage, needle biopsy, and even conization. Since the lesion was primarily located in the upper lateral portion of the cervical canal, it is possible that it was not reached by conization or needle biopsy. As the diagnosis of endometriosis requires the identification of both endometrial glands and stroma, it is important to recognize that limited tissue sampling may yield false-negative results, and biopsy alone may be insufficient for diagnosis in certain cases. In conclusion, cervical endometriosis should be included in the differential diagnosis of a cervical mass, particularly when imaging reveals a solid lesion with cystic components and no overt invasive features. However, the overlap in radiologic and clinical characteristics with cervical malignancies underscores the potential need for surgical excision in selected cases, for both definitive diagnosis and appropriate management. This case emphasizes the importance of heightened clinical awareness of this rare condition to avoid misdiagnosis and unnecessary overtreatment.

This article was not commissioned and was peer reviewed.

Kohei Sakabe contributed to patient care, conception of the case report, acquiring and interpreting the data, undertaking the literature review and drafting the manuscript. Masumi Sunada contributed to patient care, conception of the case report, acquiring and interpreting the data, undertaking the literature review and drafting the manuscript. Mana Taki contributed to conception of the case report, acquiring and interpreting the data, undertaking the literature review, drafting the manuscript and revising it critically for important intellectual content. Taito Miyamoto contributed to drafting the manuscript and revising the manuscript for important intellectual content. Rin Mizuno contributed to drafting the manuscript and revising the manuscript for important intellectual content. Koji Yamanoi contributed to drafting the manuscript and revising the manuscript for important intellectual content. Ryusuke Murakami contributed to patient care, conception of the case report and drafting the manuscript. Hiroaki Ito contributed to patient care, drafting the manuscript and revising the manuscript for important intellectual content. Masaki Mandai contributed to drafting the manuscript and revising the manuscript for important intellectual content. All authors approved the final submitted manuscript.

Cervical endometriosis is a rare, benign gynecological condition characterized by ectopic endometrial glands and stroma within the cervix [ 1 , 2 ]. It typically affects women of reproductive age and may be asymptomatic or present with abnormal bleeding, pelvic pain, or mucoid vaginal discharge. Magnetic resonance imaging (MRI) often reveals a well-circumscribed multicystic mass; however, owing to overlapping clinical and radiological features, distinguishing it from cervical adenocarcinoma can be challenging. While cervical adenocarcinoma generally presents as a solid, infiltrative lesion, cervical endometriosis tends to show a cystic pattern with preservation of cervical architecture. Histopathological examination is essential for a definitive diagnosis. This report concerns a case of cervical endometriosis in which repeated biopsies failed to establish a definitive diagnosis, and hysterectomy was ultimately performed because of the persistent suspicion of malignancy. The diagnostic process and clinical management are described in detail.

The authors declare that they have no competing interest regarding the publication of this case report.