Endometrial Synovial-like Metaplasia Associated With Levonorgestrel-releasing Intrauterine System:

Whole-exome sequencing reveals novel candidate single nucleotide variations for preventing adverse effects of levonorgestrel implantation

Aim: To identify novel genes associated with adverse effects of levonorgestrel (LNG) implants based on comparative whole-exome sequencing. Materials & methods: A cohort comprising 104 participants, including 52 controls and 52 women with LNG-related adverse effects, was recruited. Seven cases and eight controls were selected for whole-exome sequencing. We verified 13 single nucleotide variations (SNVs) related with integrin-mediated signaling pathway and cell proliferation using the MassARRAY platform. Results: Finally, we screened 49 cases and 52 controls for analyses. Two SNVs (rs7255721 and rs1042522) were located in ADAMTS10 and TP53, respectively, and significantly different between two groups. These two SNVs lead to changes in protein structure and physicochemical parameters. Conclusion: Here, we defined two pathogenic mutations related to adverse LNG effects.

Effects of progestin-only contraceptives on the endometrium

INTRODUCTION

The contraceptive activity of synthetic progestins is mediated through three basic mechanisms: (a) An anti-gonadotrophic action leading to the inhibition of ovulation; (b) Changes in cervical mucus characteristics that inhibit sperm penetration and (c) desynchronization of the endometrial picture necessary for implantation.

AREAS COVERED

Mechanisms involved in the progestin-induced endometrium desynchronization are individually reviewed for each of the routes of administration and, whenever possible, by individual members of the various families of synthetic progestin derivatives.

EXPERT OPINION

For contraceptive purposes, progestins are today administered through several routes: orally, as injections, subdermally and via the vagina or the uterine cavity. Given this variety of modalities, their effects may differ, depending on the route of administration, concentration reached at the level of the endometrium and the duration of use. These are characterized by inactivation of the endometrium. Progestin-only contraception provides a safe and effective control of fertility regulation, although, they are associated with the problem of endometrial break through bleeding that may lead to discontinuation. Unfortunately, in spite of a major research effort over two decades, there is not, as yet, an established long-term intervention available to manage bleeding irregularities, making mandatory a deeper understanding of the mechanisms involved is required.

Benign and Premalignant Lesions of the Endometrium

In this review, we highlight the benign and premalignant lesions of the endometrium that the pathologist may encounter in daily practice. We begin by detailing our current understanding of excess estrogen in the progression of endometrial neoplasia. We outline the currently accepted terminology to be used when evaluating proliferative endometrial lesions, while highlighting their key features. Attention is then turned to the molecular underpinnings of neoplastic progression and how this can be exploited with immunohistochemical stains when appropriate. Finally, we discuss types of metaplasia and their associations, including so-called papillary proliferations of the endometrium.