Usefulness of the ‘cosmos pattern’ for differentiating between cervical gastric‐type mucin‐positive lesions and other benign cervical cystic lesions in magnetic resonance images

Abstract

Aim: To evaluate the usefulness of the 'cosmos pattern' (CP) on magnetic resonance (MR) images for differentiating between gastric-type mucin-positive lesions (GMPL) and gastric-type mucin-negative lesions (GMNL). Methods: This study included 131 patients with clinical suspicion of lobular endocervical glandular hyperplasia (LEGH) who underwent pelvic MR imaging and a Pap smear and/or latex agglutination assay. Differences in MR findings, such as cyst and solid component patterns, cervical location and T1-weighted image (T1WI) signal intensity, were compared between GMPL and GMNL. The diagnostic performances of the findings were assessed. Results: The frequencies of CP (63.1%), upper part (UP) lesions (72.3%) and hypointense area compared with the cervical stroma on T1WI (61.3%) were significantly greater in GMPL than in GMNL (P < 0.05). The sensitivity, specificity, positive predictive value, negative predictive value and odds ratio of the CP for diagnosis of GMPL were 63.1%, 87.9%, 83.7%, 70.7% and 12.4, respectively. In GMNL, a 'macrocystic pattern' was observed in 65.2% of patients; an isointense or hyperintense area on T1WI was observed in 86.4% of patients. The sensitivity was highest (90.8%) when one or more of the following were observed: CP, UP lesion, or hypointense area on T1WI. The specificity was highest (95.5%) when the CP was observed as a hypointense area on T1WI. Conclusion: The CP is a highly specific finding for diagnosis of GMPL. If the CP is observed as a hypointense area compared with the cervical stroma on T1WI, GMPL (i.e., LEGH or gastric-type mucinous carcinoma) should be strongly suspected.

Case Report: Gastric-Type Endocervical Adenocarcinoma Mimicking Submucosal Myoma Under Hysteroscopy

“…Pelvic MRI features of “cosmos pattern” (CP), which means some small cysts or solid components are present in the central part of the lesion surrounded by relatively large cysts, can help to distinguish gastric-type mucin-positive lesions (GMPL) such as LEGH and GAS from gastric-type mucin-negative lesions (GMNL) such as cervical Nabothian cyst. If CP is observed as a hypointense area compared with the cervical stroma on T1WI, GMPL should be strongly suspected ( 16 ). A combination of cytology and MRI and an assay for gastric-type mucin have been suggested to be effective for the early detection and preoperative diagnosis of GAS ( 17 ).…”

Biology and management of lobular endocervical glandular hyperplasia

“…Ohya et al also reported the difficulty of diagnosing focal MDA in LEGH by MRI. 46 Recently, Omori et al reported additional MRI finding of LEGH, termed the raspberry pattern, that is, close aggregation of small cysts, lacking surrounding outer larger cysts (Figure 6f). They reported that surgically confirmed LEGH exhibited a raspberry pattern on MRI and was often postmenopausal and associated with AIS.…”

“…MRI is an important diagnostic tool for the cystic disorders of the cervix. 14 , 26 , 42 , 46 , 47 We classified T2‐weighted MRI findings of the abovementioned cervical disorders often presenting with multicystic lesions as follows: (i) solid pattern (a solid component was noted), suggesting malignancy such as MDA/GAS; (ii) invasion pattern (diffuse and solid high T2‐weighted signal with an unclear margin in the cervical stroma), also suggesting malignancy; (iii) cosmos pattern (diffuse or microcystic parts surrounded by medium to large cysts), suggesting LEGH; (iv) microcystic pattern (aggregation of small cysts without peripheral large cysts), suggesting LEGH or malignancy; (v) coarse cystic pattern (irregular aggregation of medium to large cysts without a solid or microcystic component), suggesting a NC (Figure 6c, d, e ). The correct rate of the MRI classification for diagnosing LEGH and MDA/GAS was 85% ~ 90% and 67% ~ 70%, respectively.…”

Human papillomavirus‐independent cervical cancer and its precursor lesions

“…23,26 This cosmos pattern is considered highly specific for gastric-type mucin-producing lesions, especially if the area exhibiting this pattern is hypointense relative to the surrounding cervical stroma. 26 Compared with LEGH, GAC is more likely to exhibit a solid-cystic pattern with inner solid components, deep stromal infiltration, indistinct borders and restricted diffusion on MRI (Figure 2). Presence of adnexal or peritoneal metastases and invasion of parametrium or vagina also raises the suspicion of a malignant lesion on cross-sectional imaging.…”

“…LEGH is usually located at the superior cervix, close to the internal os. The cysts are small (microcystic) and typically have a floret‐like arrangement, appearing as the ‘cosmos pattern.’ 23,26 This cosmos pattern is considered highly specific for gastric‐type mucin‐producing lesions, especially if the area exhibiting this pattern is hypointense relative to the surrounding cervical stroma 26 . Compared with LEGH, GAC is more likely to exhibit a solid‐cystic pattern with inner solid components, deep stromal infiltration, indistinct borders and restricted diffusion on MRI (Figure 2).…”