A rare anatomic variant of a markedly enlarged anterior external arcuate fasciculus (AEAF) on the ventral medullary surface is reported and compared to two controls. The hypertrophic AEAF was nine times larger in diameter than normal, whereas the arcuate nucleus (AN) and inferior olivary nucleus (ION) appeared histologically normal in size and neuronal distribution, and morphometric analysis of the AN confirmed that it was within the normal range. Calbindin-2 (calretinin, CALB2) expression was identified in the AN and in the fibers of the normal AEAF. The hypertrophic AEAF did not contain calbindin-2–expressing fibers. CALB2 expression was also present in the ventrolateral portion of the ION, both in the index case and in one of the control cases. The origin of the additional fibers was not identified; however, the potential origin of these fibers and its implications for the development of the AEAF are discussed.

Atypical hemangioma (including sclerosing and/or hyalinizing hemangioma) of the liver is a rare variant of hepatic hemangioma, which is the most common benign hepatic tumor. Atypical hemangioma can be indistinguishable from malignancy, primary, or metastatic, based on imaging characteristics. We describe a case of a 70-year-old man with weight loss, occasional bloody stool, change in caliber of stool, and laboratory abnormalities who was found to have multiple hepatic lesions concerning for metastases. We demonstrate that knowledge of the appearance of atypical hemangioma and its inclusion in the differential diagnosis of hepatic lesions can alter patient management and be important to consider before invasive therapies are planned.

A 15-year-old girl presented with intermittent nausea and vomiting, headache, and vision changes. MR imaging of the brain revealed an avidly enhancing infratemporal dural-based mass arising from the tentorium, with hyperintensity on T2WI and transdural extension into the posterior cranial fossa. The well-encapsulated fibrous tumor was resected en bloc after cauterization of its rich tentorial arterial supply. Histologic examination demonstrated pleomorphic myofibroblastic cells admixed with an inflammatory infiltrate. Spindle cells showed strong, diffusely positive immunostaining for anaplastic lymphoma kinase, and genomic sequencing uncovered a tropomyosin 3 gene and anaplastic lymphoma kinase fusion and an activating mutation in the Kirsten rat sarcoma oncogene. A diagnosis of inflammatory myofibroblastic tumor was made. Primary intracranial involvement of inflammatory myofibroblastic tumor is exceptionally rare, and few cases that feature an anaplastic lymphoma kinase translocation have been described. Inflammatory myofibroblastic tumor‐CNS is an important differential diagnosis for dural-based lesions in children and young adults due to its propensity for recurrence and malignant degeneration.