Transgender women experience gender dysphoria due to a gender assignment at birth that is incongruent with their gender identity. Transgender people undergo different surgical procedures and receive sex steroids hormones to reduce psychological distress and to induce and maintain desired physical changes. These persons on feminizing hormones represent a unique population to study the hormonal effects on breast development, to evaluate the risk of breast cancer and perhaps to better understand the precise role played by different hormonal components. In MTF (male to female) patients, hormonal treatment usually consists of antiandrogens and estrogens. Exogenous hormones induce breast development with the formation of ducts and lobules and an increase in the deposition of fat. A search of the existing literature dedicated to hormone regimens for MTF patients, their impact on breast tissue (incidence and type of breast lesions) and breast cancer risk provided the available information for this review. The evaluation of breast cancer risk is currently complicated by the heterogeneity of administered treatments and a lack of long-term follow-up in the great majority of studies. Large studies with longer follow-up are required to better evaluate the breast cancer risk and to understand the precise mechanisms on breast development of each exogenous hormone.

Background: MEIS1::NCOA1/2 fusion sarcomas are a recently described molecular entity arising predominantly in the genitourinary and gynecologic tracts. Their clinical presentation is often misleading, and no standardized treatment guidelines currently exist. Methods: A literature review was conducted using PubMed to identify all reported cases of molecularly confirmed MEIS1::NCOA1/2 fusion sarcomas. Clinicopathological, molecular, treatment, and outcome data were extracted for comparative analysis. Case: We report the case of a 38-year-old nulliparous woman who presented with a right vulvar induration clinically consistent with a Bartholin gland cyst. Surgical excision revealed a spindle cell mesenchymal tumor harboring a MEIS1::NCOA2 fusion transcript and a CTNNB1 exon 3 mutation, with probable incomplete resection margins. A local recurrence was documented by MRI and PET–CT at eight months. Surgical re-excision revealed diffuse involvement and complete excision was considered uncertain. Adjuvant external beam radiotherapy followed by an MR-Linac boost was administered. Discussion: This case highlights the diagnostic challenge of Bartholin gland masses. We provide a review of the literature on MEIS1::NCOA1/2 fusion sarcomas and examine the potential aggressiveness of tumors that additionally harbor a CTNNB1 mutation. Given the nonspecific immunophenotype of this entity, this case underscores the indispensable role of RNA-based molecular sequencing in the diagnosis of low-grade spindle cell tumors when immunohistochemistry proves inconclusive. We further discuss the surgical challenges inherent to this anatomical region and explore intention-to-treat radiotherapy as a potential therapeutic option. Conclusions: We report a rare case of a MEIS1::NCOA2 fusion-positive sarcoma arising in the Bartholin gland region, and, to our knowledge, the first case in which radiotherapy with curative intent has been explored for this entity. This observation expands the limited literature on this emerging clinicopathological entity.

The human breast, as mentioned by Gudjonsson and co-authors