HighlightsIntestinal obstructions caused by external compression from the appendix are rare.Low-grade appendiceal mucinous neoplasm (LAMN) with torsion is rarer still.LAMN have the potential to lead to pseudomyxoma peritonei.Surgical resection for LAMN is the standard treatment.The appropriate surgical procedure, however, remains controversial.

HighlightsAppendiceal neurofibromas (AN) in Neurofibromatosis type (NF) 1 are rare.AN in NF1 with Low-grade appendiceal mucinous neoplasms (LAMNs) are extremely rare.AN and LAMNs have potential for malignant transformation.Surgical resection is the standard treatment for patients with AN and LAMNs.However, appropriate surgical procedure remains controversial.

HighlightsNon-perforating acute appendicitis with septic DIC is extremely rare.Nowadays, interval appendectomy has become popular.However, judging the limit of conservative treatment for acute appendicitis is a critically important matter.Appendectomy should be performed for non-perforating acute appendicitis with septic DIC.