[Carcinoma of the transverse colon]. / Les tumeurs du côlon transverse.

Carcinoma of the transverse colon accounts for 10% of all colorectal cancer. Diagnosis is often delayed and complicated forms (perforation, fistulization, obstruction) occur in 30-50% of cases. The progression of symptoms is often insidious and tumors may be voluminous by the time of diagnosis. Right sided tumors are typically bulky and late-stage; perforation may lead to abdominal wall or retroperitoneal abscess. Tumor can also extend or fistulize into adjacent organs. Distal transverse cancers may be small annular lesions which are prone to obstruction. Cancers present as T4 lesions in 20-40% of cases. Abdominal CT is the best test to evaluate the loco-regional extension of advanced tumors. Their central location and advanced stage at presentation results in an extensive differential diagnosis. This central location also poses difficult surgical choices for lymph node dissection, extent of resection, and re-establishment of intestinal continuity. Surgical series which focus on transverse colon cancer date from the 1970-80's; they show curative resections in only 50% with morbidity/mortality of 20% and a global five year survival of less than 35%; they were considered to have a particularly poor prognosis.

[Right colon diverticulitis]. / Les diverticulites du côlon droit.

Diverticulitis involving the right colon is uncommon in the Occident; only one case for every 300 cases of appendicitis occurs in Western countries compared to a ratio of 1/40-1/180 in Asia. The preferential localization of diverticula in the right colon among Asiatics is probably due to genetic factors. In Asia as in the West, a right colon diverticulum is more likely to cause hemorrhage than diverticulitis. The peak age of symptoms is 40-45 years and the sex ratio is 1:1. The patient most commonly presents with symptoms suggestive of acute appendicitis, acute localized peritonitis, or, more rarely, a psoas abscess. Clinical exam reveals an inflammatory mass in the right lower quadrant in 30% of cases; diffuse peritonitis, large abscesses, and fistulae are rare. Helical CT scan is the best tool for establishing the diagnosis and also helps to rule out other possible etiologies in the differential diagnosis-particularly a perforated right colon cancer. In noncomplicated cases with convincing evidence for the diagnosis by CT scan, a conservative (non-surgical) treatment with antibiotics is possible; a later stage colonoscopy will rule out other colonic lesions. More commonly, the correct diagnosis is only made after embarking on an appendectomy via a McBurney incision; the surgical strategy thereafter depends on the level of suspicion regarding the diagnosis and the extent and complexity of the diverticulitis. Therapeutic options may be conservative (appendectomy), limited (diverticulectomy, or extensive (ileocecal resection or right hemicolectomy). For complicated disease (abscess, localized perforation), an aggressive surgical approach is warranted. Surgical strategies need to be validated, particularly in the light of the increasing use of the laparoscopic approach for suspected appendicitis.

[Situs invertus, a mirror image]. / Situs invertus, une image en miroir.

INTRODUCTION: Situs inversus is a rare congenital abnormality often revealed in the childhood. In adults with acute abdomen, it's important to know this organs' inversus for diagnosis and surgery. OBSERVATION: A 36 year-old woman presented with symptoms of appendicitis; she had a complete situs inversus diagnosed in the childhood. Abdominal computed tomography showed signs of diverticulitis but after medical therapy, a colonoscopy revealed a sigmoid tumor. A left colectomy was performed by laparotomy without any particular problems; pathologic examination confirmed a colonic adenocarcinoma T3N0. DISCUSSION: Situs inversus is complete, incomplete or ambiguous. It may be associated with other malformations, especially cardiac abnormalities. When this malformation is unknown in the adulthood, this inversion of organs may be responsible of diagnostic difficulties, especially during the physical examination of an acute abdomen. If the patient underwent surgery, the adaptation to this inversion of organs is relatively easy. In the international literature, the association of this abnormality with colonic tumors seems to be fortuitous.

[Castleman disease localized in the mesentery]. / Maladie de Castleman localisée au mésentère.

We report a case of Castleman disease in the mesentery localized to a 58 year-old man. The mass is hypervascular on CT, which can suggest the diagnostic before surgery.