A newly identified allelic mutation c.110C>T in the CTNNB1 gene in diffuse adenomyosis among young women-a report of two cases.

BACKGROUND

Adenomyosis (AM) is a common benign gynecological disease, defined by the presence of endometrial glands and stroma deep within the myometrium, which is associated with hypertrophy and hyperplasia of the adjacent myometrium. It mainly occurs in women of reproductive age and rarely exhibits invasive growth patterns in young women. This study presents two rare cases of diffuse AM in two young females, with the same CTNNB1 mutation site that has not been reported before.

CASE DESCRIPTION: Case one, a 29-year-old female, G0P0, the patient experiences repeated contact bleeding, increased menstrual flow, and abdominal pain. Ultrasound examination revealed a weak echo area in the uterine cavity, and subsequent surgical intervention revealed extensive necrotic tissue resembling rotten fish in the uterine cavity, extending to more than half of the muscle layer. Case two, a 26-year-old female, G0P0, the menstrual flow increased for 4 years without any other symptoms. Computed tomography (CT) imaging demonstrated a space-occupying lesion within the uterine cavity, with uneven density and enhancement, and an ill-defined border with the anterior uterine wall muscle. During the procedure, a block of tissue approximately 8cm in diameter was observed on the right uterine wall, accompanied by several small polypoid protrusions nearby. Histopathological examination of two cases revealed multiple endometrial polyps, characterized by widespread distribution of endometrial glands and stroma within the uterine muscle wall, with some glands showing dilation and a dense increase in spiral arterioles within the stroma. The deepest lesions are all close to the uterine serosa. The final diagnosis was extensive AM. Next-generation sequencing revealed a CTNNB1 (EX3 c.110C>T p.S37F) gene mutation at the same site. Immunohistochemical detection of β-catenin revealed cell membrane staining, and immunofluorescence also confirmed that β-catenin staining was localized to the cell-membrane. The surgery alleviated their symptoms and improved their quality of life. Up to now, no other adverse symptoms have been observed during follow-up.

CONCLUSIONS

The study first identified a mutation of CTNNB1 gene in diffuse AM among young women. The new discovery is expected to provide a new perspective for the pathogenesis and molecular pathology research of AM.