Lymphatic endothelial cell RXRα is critical for 9-cis-retinoic acid-mediated lymphangiogenesis and prevention of secondary lymphedema.

Secondary lymphedema is a debilitating disease characterized by abnormal soft tissue swelling and caused by lymphatic system dysfunction. Despite a high prevalence of secondary lymphedema after cancer treatments, current management is supportive and there are no approved therapeutic agents that can thwart disease progression. We have previously demonstrated that 9-cis-retinoic acid (9-cisRA) has the potential to be repurposed for lymphedema as it mitigates disease by promoting lymphangiogenesis at the site of lymphatic injury. Although the efficacy of 9-cisRA has been demonstrated in previous studies, the mechanism of action is not completely understood. In this study, we demonstrate that when RXRα is specifically deleted in lymphatic endothelial cells, 9-cisRA fails to induce lymphangiogenesis in vitro and prevent pathologic progression of postsurgical lymphedema in vivo. These findings demonstrate that downstream nuclear receptor RXRα plays a critical role in the therapeutic efficacy of 9-cisRA in postsurgical lymphedema.

Low-Grade Papillary Schneiderian Carcinoma in the Nasal Cavity.

Only a limited number of documented low-grade papillary Schneiderian carcinoma (LGPSC) cases have been reported since its initial description in 2015. In this study, the authors present a case report involving a young female patient who presented with this rare condition localized in the nasal cavity. On the basis of histologic examination of a small tumor sample, the initial diagnosis pointed to squamous cell carcinoma. After the surgery, however, the final histologic diagnosis was confirmed as LGPSC. Finally, after surgical intervention, the histologic diagnosis was confirmed as LGPSC. Remarkably, over a period of 22 months, the patient showed no signs of recurrence or metastasis. To achieve an accurate diagnosis and implement appropriate treatment strategies for LGPSC, a comprehensive understanding of both its clinical and histologic characteristics is necessary.