Classic presentation of appendicular neoplasms in early stage includes appendicitis-like symptoms. For mucinous adenocarcinoma, it presents at an average age of 60 years, this is why when they present these symptoms a high index of suspicion must be maintained. Only one case has been reported of an appendiceal neoplasm with a thigh abscess. We present a 65-year-old with a preoperative diagnosis of an appendiceal phlegmon with and iliopsoas and thigh abscess. Percutaneous drainage and thigh drainage were initially performed. Due to persisting fever and increased abdominal symptoms, 48 h postoperative hours, on multidisciplinary discussion, exploratory laparoscopy was decided, finding the iliac abscess and a perforated appendix. Right hemicolectomy was performed, revealing a mucinous appendicular carcinoma. Conservative management of a mass or appendiceal abscess has a high success rate and low complication rate during the initial period but despite this, some patients must undergo emergency surgery. Right hemicolectomy was performed because of the large inflammatory compromise and adhesions of the appendix and caecum and a more conservative approach could not be performed due to the deformation of anatomic structures. This has been a complex case, not only for its different approaches but also because of its singularity of presentation, this is why it has to be taken into account the group age that it has to be dealt with, clinical presentation, anamnesis, etc. There are no guidelines for the management of this disease but it is unquestionable that multidisciplinary management leads to better outcomes. • Only one case has been reported of an appendiceal neoplasm with a thigh abscess. • The classic presentation of appendicular neoplasms includes appendicitis-like symptoms. • We performed a right hemicolectomy and thigh abscess drainage. • No guidelines exist but multidisciplinary management leads to better outcomes.