Objective: Lymphatic malformations (LMs) are challenging to manage, particularly those involving the cervicofacial region and airway. Traditional therapy is sclerotherapy and/or resection. We aim to establish the emerging therapeutic role of sirolimus.

Kaposiform lymphangiomatosis is an uncommon generalized lymphatic anomaly with distinctive clinical, radiologic, histopathologic, and molecular findings. Herein, we document the pathology in 43 patients evaluated by the Boston Children's Hospital Vascular Anomalies Center from 1999 to 2020. The most frequent presentations were respiratory difficulty, hemostatic abnormalities, and a soft tissue mass. Imaging commonly revealed involvement of some combination of mediastinal, pulmonary, pleural, and pericardial compartments and most often included spleen and skeleton. Histopathology was characterized by dilated, redundant, and abnormally configured lymphatic channels typically accompanied by dispersed clusters of variably canalized, and often hemosiderotic, spindled lymphatic endothelial cells that were immunopositive for D2-40, PROX1, and CD31. An activating lesional NRAS variant was documented in 9 of 10 patients. The clinical course was typically aggressive, marked by hemorrhage, thrombocytopenia, diminished fibrinogen levels, and a mortality rate of 21%.

Sirolimus is a mammalian target of rapamycin (mTOR) inhibitor that blocks signals from the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT) pathway, which coordinates cell proliferation and survival central to the development of vascular anomalies. 1,2 Oral sirolimus is widely used to treat varied vascular anomalies and is associated with diverse adverse events (AEs), including leukopenia, gastrointestinal symptoms, infectious complications, and dyslipidemia. 1,2 Limited data exist regarding dermatologic AEs in populations with vascular anomalies.

This was an open, single centre study, to evaluate the safety and efficacy of ondansetron in the treatment of co-trimoxazole associated nausea and vomiting in AIDS patients. Sixteen patients presenting with their first episode of HIV-associated Pneumocystis carinii pneumonia (PCP) on high dose co-trimoxazole were given ondansetron 8 mg orally, every 8 h. Measurements were made from data recorded by each patient on diary cards. In this study 11 out of 16 (69%) patients on ondansetron experienced good control of emesis (2 or less emetic episodes) on their 'worst day' of therapy and 8 out of 16 (50%) of patients demonstrated good control of emesis throughout their treatment with co-trimoxazole. Good control of nausea (mild or none) was achieved in 7 out of 16 (47%) patients. A total of 7 patients were able to complete the full course of co-trimoxazole whilst on ondansetron. One serious adverse event (Stevens-Johnson syndrome) was reported and felt to be unrelated to ondansetron. If conventional anti-emetics fail to achieve control of symptoms or have unacceptable side effects, ondansetron may represent a possible alternative.