A Case of a Giant Borderline Phyllodes Tumor Early in Pregnancy Treated with Mastectomy and Immediate Breast Reconstruction.

Breast tumors in pregnancy are often times diagnosed at advanced stages secondary to difficulty distinguishing between pathologic from normal physiologic changes. Often benign, phyllodes tumors are rare fibroepithelial stromal tumors of the breast, most commonly diagnosed in the 4th and 5th decades of life. However, these tumors may be characterized by malignancy with metastases in 10% of cases. In this paper, we report a novel case of a young woman presenting at 8 weeks gestation with a large borderline phyllodes tumor. An exceedingly rare condition, with only nine previously reported cases, phyllodes tumors in pregnancy frequently display more aggressive characteristics with larger median tumor size, more malignant potential, and more rapid growth rate. Here, we describe our experience safely and effectively treating this rare condition in a young gravid women with mastectomy and immediate breast reconstruction in the second trimester.

Epithelioid Myofibroblastoma of the Breast: A Report of Two Cases with Discussion of Diagnostic Pitfalls.

Mesenchymal lesions of the breast are uncommon lesions which present diagnostic dilemmas for even the most experienced pathologists. Here, we present two cases of the epithelioid-variant of myofibroblastoma which were misdiagnosed as malignant lesions. Careful integration of clinical presentation, imaging, and close examination of the gross, histologic, and immunohistochemical findings can assist in differentiating these challenging lesions and avoiding diagnostic pitfalls.

Structured illumination microscopy for cancer identification in diagnostic breast biopsies.

Breast cancer is the second most common cancer diagnosed in women in the US with almost 280,000 new cases anticipated in 2023. Currently, on-site pathology for location guidance is not available during the collection of breast biopsies or during surgical intervention procedures. This shortcoming contributes to repeat biopsy and re-excision procedures, increasing the cost and patient discomfort during the cancer management process. Both procedures could benefit from on-site feedback, but current clinical on-site evaluation techniques are not commonly used on breast tissue because they are destructive and inaccurate. Ex-vivo microscopy is an emerging field aimed at creating histology-analogous images from non- or minimally-processed tissues, and is a promising tool for addressing this pain point in clinical cancer management. We investigated the ability structured illumination microscopy (SIM) to generate images from freshly-obtained breast tissues for structure identification and cancer identification at a speed compatible with potential on-site clinical implementation. We imaged 47 biopsies from patients undergoing a guided breast biopsy procedure using a customized SIM system and a dual-color fluorescent hematoxylin & eosin (H&E) analog. These biopsies had an average size of 0.92 cm2 (minimum 0.1, maximum 4.2) and had an average imaging time of 7:29 (minimum 0:22, maximum 37:44). After imaging, breast biopsies were submitted for standard histopathological processing and review. A board-certified pathologist returned a binary diagnostic accuracy of 96% when compared to diagnoses from gold-standard histology slides, and key tissue features including stroma, vessels, ducts, and lobules were identified from the resulting images.