Imaging diagnosis
Case 230
【Progress】
The imaging diagnostic letter was sent to the local clinic.
【Discussion】
In uterus lesions, cervical cancer is the most concern for radiologists to detect on MRI and CT. The most cervical cancer is squamous cell carcinoma.
However, the incidence of adenocarcinoma gradually increases to 15 to 20 % of all cervical cancers (1, 2). Squamous cell cancer and adenocarcinoma are derived from papilloma virus. Meanwhile, mucinous adenocarcinomas such as gastric cancer-type adenocarcinoma, minimal deviation adenocarcinoma (= adenoma malignum) are not arisen from papillomavirus infection (1, 2).
As cervical cystic lesion, Nabothian cyst is first listed. It is believed to arise from occlusion of gland outlet. Next, tunnel cluster is listed. It is believed to be proliferation of cervical gland. These lesions cause no symptoms and are occasionally encountered on pelvic MRI. When patients have symptoms of increasing vaginal discharge whose MRI findings revealed cystic lesion at uterine cervix, adenoma malignum was once recorded for imaging diagnosis. New concept on cervical cystic lesions has emerged since the beginning of 21 century. Based on the pathological findings of no malignancy, lobular endocervical glandular hyperplasia (LEGH) is termed in taking place of adenoma malignum. As benign cystic lesions, Nabothian cyst tunnel cluster and LEGH are listed (1-4).
When early carcinoma arises from LEGH, it is called minimum deviation adenocarcinoma or adenoma malignum (5). Subsequently, it develops to gastric cancer-type adenocarcinoma. Now minimum deviation adenocarcinoma or adenoma malignum, gastric cancer-type adenocarcinoma is a series of mucinous adenocarcinoma. Namely, minimum deviation adenocarcinoma and/or adenoma malignum are highly differentiated mucinous adenocarcinoma.
To summarize, Nabothian cyst is a benign cyst with occlusion of gland outlet, tunnel cluster is proliferation of cervical gland, LEGH is literally hyperplasia of cervical gland, adenoma malignum (minimal deviation adenocarcinoma) is dysplasia or early mucinous carcinoma, gastric-type adenocarcinoma is highly or moderately differentiated mucinous adenocarcinoma.
The characteristic of LEGH is collection of a large cyst and its surrounding small cysts on MRI which is termed as ‘cosmos sign’(1, 3-7). When solid component is included in cosmos sign, malignant potential becomes predominant; adenoma malignum to gastric cancer-type adenocarcinoma which is now believed to be a series of mucinous adenocarcinoma. In our case, a large cyst and its surrounding small cyst without solid component (positive cosmos sign) (Fig 3C) were demonstrated on MRI, indicative of LEGH.
The differences between Nabothian cyst and LEGH followed by malignant potential cystic tumors are patient symptoms of much volume of vaginal discharge rather than MRI findings.
【Summary】
The differences between Nabothian cyst and LEGH followed by malignant potential cystic tumors are patient symptoms of much volume of vaginal discharge rather than MRI findings.
【References】
1.Ohya A, et al. Uterine cervical adenocarcinoma associated with lobular endocervical glandular hyperplasia: Radiologic–pathologic correlation. J Obstetrics and Gynaecology research. 2018; 44: 312-322
2.Nara M, et al. Lobular endocervical glandular hyperplasia as a presumed precursor of cervical adenocarcinoma independent of human papillomavirus infection. Gynecol Oncol 2007; 106: 289– 298.
3.Yamashita Y, et al. Adenoma malignum: MR appearances mimicking nabothian cysts. Am J Roentgenol 1994; 162: 649– 650.
4.Oguri H, et al. MRI of endocervical glandular disorders: Three cases of a deep nabothian cyst and three cases of a minimal‐deviation adenocarcinoma. Magn Reson Imaging 2004; 22: 1333– 1337.
5.Doi T, et al. Adenoma malignum: MR imaging and pathologic study. Radiology 1997; 204: 39– 42.
6.Nucci MR, et al. Lobular endocervical glandular hyperplasia, not otherwise specified: A clinicopathologic analysis of thirteen cases of distinctive pseudoneoplastic lesion and comparison with fourteen cases of adenoma malignum. Am J Surg Pathol 1999; 23: 886– 891.
7.Takatsu A, et al. Preoperative differential diagnosis of minimal deviation adenocarcinoma and lobular endocervical glandular hyperplasia of the uterine cervix: multicenter study of clinicopathology and magnetic resonance imaging findings. Int J Gynecol Obstet 2011; 21: 1287– 1296.
2021.5.12