Multiple Occipital Bone Lytic Lesions Containing Ectopic Cerebellar Parenchyma Mimicking Neoplasia

Background Nonlethal neural tube defects are developmental malformations with complex pathogenesis usually manifested at birth or in childhood. Case description We report the case of a 61-year-old woman without significant previous clinical history presenting for neck pain and stiffness. An extensive workup detected multiple lytic lesions within the occipital bone and cervical vertebrae, suspicious for multiple myeloma or metastatic disease. Surgical resection of the occipital bone lesions revealed ectopic cerebellar tissue, some containing folia with mature cortical lamination, and no evidence of malignancy. Conclusions To our knowledge, this study describes the oldest individual presenting with ectopic cerebellar tissue and the only instance in which oncologic workup for malignancy was carried out prior to resection. It also proposes surgical resection as a diagnostic and curative approach for this complex basicranium and neural developmental defect, and discusses retinoic acid toxicity as a possible cause of its occurrence.