Gingival metastasis of angiosarcoma of the breast as a first manifestation of spreading disease: Case report and review of the literature.

BACKGROUND: Angiosarcoma is an aggressive malignant neoplasm of vascular origin. Oral metastases of angiosarcoma are rare and have a non-specific clinical presentation, thus the diagnosis may be challenging. CASE REPORT: Herein we report a case of a 34-year-old female patient after treatment of a high-grade angiosarcoma of the breast, who presented an asymptomatic bleeding purplish nodule in the maxillary interdental papilla between the first and second premolar. A biopsy was performed, and the histological examination revealed infiltration by malignant neoplasm of epithelioid and fusocellular pattern. Immunohistochemical analysis demonstrated that neoplastic cells were positive for ERG and CD31, and negative for cytokeratins AE1/AE3, confirming the diagnosis of metastatic angiosarcoma. After investigation, multiple metastases were discovered. The patient is under management with chemotherapy and palliative radiotherapy for the bone lesions. CONCLUSION: Metastases should be considered in the differential diagnosis of oral lesions in patients with a previous history of cancer. Due to the morphology of angiosarcomas, the metastatic lesions may resemble benign vascular lesions, therefore, biopsy is mandatory to exclude malignancy.

Uterine Sarcoma With EML4::NTRK3 Fusion: A Spectrum of Mesenchymal Neoplasms Harboring Actionable Gene Fusions.

NTRK gene fusions are part of a paradigm shift in oncology, arising as one of the main genomic alterations with actionability in the so-called "agnostic setting." In gynecologic pathology, the recent description of uterine sarcoma resembling fibrosarcoma and with NTRK rearrangements ( NTRK -rearranged uterine sarcoma) highlights the importance of recognizing clinicopathological cues that can lead to genomic profiling. Herein, we report the case of a 43-year-old woman presenting with vaginal bleeding and pelvic mass. Histopathology of the tumor showed moderately atypical spindle cells arranged in long fascicles reminiscent of fibrosarcoma, along with immunohistochemical positivity for S100, CD34, and pan-tropomyosin receptor kinase. This prompted RNA-sequencing and the finding of a rare EML4::NTRK3 fusion. Clinical, histologic, and molecular findings are described, in addition to discussions regarding differential diagnoses and possible implications of the findings in clinical practice.