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Type:
Educational Exhibit
Keywords:
Cancer, Staging, MR, Pelvis, Genital / Reproductive system female
Authors:
T. Koyama1, Y. Mikami2, A. Kido3, K. Notohara1, K. Togashi3; 1Kurashiki, Okayama/JP, 2Kumamoto/JP, 3Kyoto/JP
DOI:
10.1594/ecr2015/C-1341
Background
1) The histologic spectrum of the entity
Endocervical glandular lesions showing gastric differentiation are an emerging entity,
which is characterized by the immune reactivity for gastric markers such as HIK1083 and MUC6[1].
This entity consists of a spectrum of lesions,
ranging from benign condition represented by lobular endocervical glandular hyperplasia (LEGH) to adenocarcinomas.
Adenocarcinomas with gastric differentiation consist of gastric-type mucinous adenocarcinoma (GAS) and minimal deviation adenocarcinoma (MDA),
which was previously called adenoma malignum (Fig. 1 .
MDA is now conceptually included in GAS as an extremely well-differentiated form in updated WHO classification in 2014 [2].
When the tumor shows non-well differentiated area,
it should be classified as GAS.
The incidence of GAS in Japan is estimated as one-fifth to one-fourth of all endocervical adenocarcinoma [1; 3],
whereas that of MDA is estimated as approximately 1%.
2) Historical backgrounds
The initial recognition of endocervical glandular lesion showing gastric differentiation was yielded in 1998 by the demonstration of the immunoreactivity of HIK1083 in MDA[4],
which is extremely differentiated form of mucinous endocervical adenocarcinoma and identical to previously called adenoma malignum.
In the following year,
pseudoneoplastic condition of cervical glandular lesion was described as LEGH by Nucci et al [5].
Almost simultaneously,
intestinal and pyloric gland metaplasia was described in endocervical glandular hyperplasia exhibiting similar histology to LEGH by Mikami et al [6].
Although these conditions were initially considered as benign,
accumulated case reports suggested that some of these conditions had premalignant characters associated with atypical histologic features or carcinoma in situ.
Moreover,
some of the cases were complicated by mucinous adenocarcinomas,
including MDA and endocervical carcinomas other than MDA [7; 8].
Consequently,
the concept of gastric-type adenocarcinomas (GAS) was proposed as the entity to include MDA and other adenocarcinomas showing gastric morphology [3; 8],
and these tumors were classified as a distinct subtype of mucinous cervical adenocarcinomas in WHO classification updated in 2014 [2].
3) The significance and the purpose of this review
Apart from pathologic findings,
the optimal management of the patients is determined according to the information provided by the imaging studies,
especially MR imaging.
Although only several radiologic studies have reported imaging features of these endocervical glandular lesions,
MRI features of endocervical glandular lesion showing gastric differentiation are hardly known in general radiologists,
and the distinction between benign and malignant lesions still remains controversial.
The main purpose of this exhibit is to review the characteristics of clinical,
pathologic and MRI features in these endocervical glandular lesions of gastric phenotype in correlation with pathologic findings,
and to clarify the findings for differentiating benign and malignant conditions,
along with the optical management of the patients.