Non-Syndromic Ganglioneuromatosis of the Gallbladder, an Extremely Rare Condition: Case Report and Literature Review

<b>Background and Clinical Significance</b>: Ganglioneuromatosis is a benign proliferation of mature ganglion cells, Schwann cells, and nerve fibers within the enteric or autonomic nervous system. According to the WHO classification, it encompasses a spectrum range from solitary ganglioneuroma to ganglioneuromatous polyposis and diffuse mural involvement. It is most commonly encountered in the colon and small bowel and is strongly associated with hereditary syndromes such as neurofibromatosis type 1 (NF1), multiple endocrine neoplasia type 2B (MEN2B), and Cowden syndrome. The involvement of the gallbladder is exceptional and only isolated cases have been documented. <b>Case Presentation</b>: We present the case of 64-year-old man admitted with longstanding right hypochondrium and epigastric pain, accompanied by intermittent nausea and occasional bilious vomiting. A cholecystectomy was performed and the histology result showed hypertrophic nerve fibers with interspersed mature ganglion cells within the fibromuscular layer. Immunohistochemistry supported neural origin and glial differentiations, consistent with ganglioneuromatosis of the gallbladder. The patient has no clinical evidence of NF1, MEN2B, or Cowden syndrome, adding a non-syndromic adult case to the very limited literature on this entity. <b>Conclusions:</b> This is a rare, non-syndromic adult case of gallbladder ganglioneuromatosis, contributing to the very limited literature on this entity.