Primary appendiceal mucinous adenocarcinoma alongside with situs inversus totalis: a unique clinical case

INTRODUCTION: Mucinous adenocarcinoma is a rare neoplasm of the gastrointestinal tract and one of the three major histological subtypes of the primary appendiceal adenocarcinoma. The most common type of presentation is that of acute appendicitis and the diagnosis is usually occurred after appendectomy. The accurate preoperative diagnosis and management of the above condition represents a real challenge when uncommon anatomic anomalies such intestinal malrotation and situs inversus take place. Situs inversus totalis with an incidence of 0.01% is an uncommon condition caused by a single autosomal recessive gene of incomplete penetration in which the major visceral organs are mirrored from their normal positions. CASE PRESENTATION: We present an unusual case of a 59 years old, previously healthy man presented with a left lower quadrant abdominal pain, accompanied with low fever, leukocytosis, anorexia and constipation. A chest radiograph demonstrated dextrocardia with a right side positioned stomach bubble. Both preoperative US and CT scan of the abdomen and pelvis declared situs inversus, with a characteristic thickening in its wall, appendix situated in the left lower quadrant of the abdomen. These findings reached to the diagnosis of acute appendicitis with situs inversus and a standard appendicectomy was performed. Pathologic evaluation established primary mucinous adenocarcinoma of the appendix and three months afterwards the patient underwent a subsequent extended left hemicolectomy. CONCLUSION: In conclusion, the occurrence of primary appendiceal mucinous adenocarcinoma along with situs inversus, definitely accounts as a unique clinical case. Even synchronous manifestation of primary mucinous adenocarcinoma of the appendix and situs inversus totalis represents an unusual anatomo-pathological entity, all physicians should be familiar having the knowledge to make an appropriate and accurate diagnosis that will lead to prompt and correct treatment.