Purpose or Case Report: A full-term infant presented at day five of life with gagging, desaturations and bilateral neck swelling. On physical exam, the patient was noted to have a hypopigmented patch on the chest. Family history reveals an older sibling with tuberous sclerosis complex (TSC). Genetic testing on the parents was performed after the previous delivery and as per report from the outside hospital was negative. Given the family history, further imaging was performed. Brain MRI revealed multiple cortical and subependymal tubers consistent with TSC, and echocardiography demonstrated intraventricular rhabdomyomas. Genetic testing demonstrated tuberous sclerosis complex. Given the neck swelling, a CT and MRI were performed and suggested a large mass extending from the deep neck into the mediastinum with concerns for a neurogenic tumor. Tracheostomy was required for airway stabilization. The coexistence of typical TSC lesions with an atypical neck and mediastinal neurogenic mass prompted biopsy, which revealed findings consistent with neurofibroma. Whole-genome sequencing confirmed pathogenic variants in both TSC1 and NF1, establishing the exceedingly rare coexistence of dual phakomatoses. Only a handful of such cases have been reported worldwide, with fewer than a dozen molecularly confirmed instances in the literature (1–2). The infant subsequently developed short-gut syndrome after necrotizing enterocolitis and remains TPN-dependent. Targeted therapy with sirolimus (mTOR inhibitor) and trametinib (MEK inhibitor) was initiated for tumor stabilization.