Cholecystocolonic fistula (CCF) is a rare complication of gallstone disease with a variable clinical presentation. It is difficult to diagnose CCF pre-operatively despite modern diagnostic and imaging modalities as they are often asymptomatic or incidentally discovered, often peri-operatively. However, management of this uncommon yet important finding is not very well described in the literature. The most common fistula is the cholecystoduodenal fistula, followed by the cholecystocolonic fistula; the cholecystogastric fistula is reportedly the least commonly reported. We report our experience with three cases of cholecystocolonic fistula discovered on imaging which were subsequently confirmed through surgery.

Glioblastoma is an aggressive primary central nervous system tumour that usually has a poor prognosis. Generally, the typical imaging features are easily recognisable, but the behaviour of glioblastoma multiforme (GBM) can often be unusual. Several variations and heterogeneity in GBM appearance have been known to occur. In this pictorial essay, we present cases of pathologically confirmed GBM that illustrate unusual locations and atypical features on neuroimaging, and review the relevant literature. Even innocuous-looking foci, cystic lesions, meningeal-based pathology, intraventricular and infra-tentorial masses, multifocal/multicentric lesions and spinal cord abnormalities may represent GBM. We aim to highlight the atypical characteristics of glioblastoma, clarify their importance and list the potential mimickers. Although a definitive diagnosis in these rare cases of GBM warrants histopathological confirmation, an overview of the many imaging aspects may help make an early diagnosis.

Wandering spleen is a rare entity that results from the absence or maldevelopment of the ligaments that support the spleen in its normal location. As a result, the spleen is hypermobile and may be predisposed to hilar torsion and subsequent infarction, making it a potentially fatal abdominal emergency. We present a case of a 36-year-old Afghan female who presented with an acute abdomen, and was radiologically and surgically confirmed to have a wandering spleen with torsion and complete infarction. Knowledge of this condition and its radiological findings can play a crucial role in making a correct and timely diagnosis.

Epidermoid cyst of the presacral space is a rare congenital lesion of ectodermal origin. Presacral epidermoid cysts have been previously reported in women, however are extremely rare in males. We report a case of presacral epidermoid cyst in a 55-year-old male who presented to our emergency department with acute urinary retention and history of chronic constipation. A non-contrast computed tomography scan was performed with suspicion of urolithiasis, which revealed a well circumscribed low attenuation presacral mass. Magnetic resonance imaging (MRI) of the pelvis was subsequently performed to further characterize the lesion. The mass was returning hypointense T1 and hyperintense T2 signals with few foci of T2 hypointensities. There was no post-contrast enhancement; however the lesion was showing diffusion restriction, appearing hyperintense on diffusion weighted imaging (DWI) and hypointense on the corresponding apparent diffusion coefficient map. These imaging features were consistent with an epidermoid cyst. Laparotomy with complete surgical excision of the cyst and preservation of the adjacent structures was performed. The histopathology confirmed the diagnosis. This case highlights the importance of MRI with additional sequences of diffusion weighted imaging which can be helpful to differentiate, to a good degree of confidence, among different pelvic tumors, therefore obviating the need of biopsy before surgery.

We present a rare case of histologically proven neurofibromatosis of the liver, hepatic hilum, retroperitoneum, and mesentery. An adult male who had been diagnosed with neurofibromatosis (NF) type 1 underwent a computed tomography (CT) scan for abdominal pain and vomiting. The CT scan showed a large low-attenuating lesion in the region of porta hepatis which was infiltrating along portal tracts into the liver, encasing the major vessels, and extending into the retroperitoneum and mesentery. Based on the radiological findings, a differential diagnosis of plexiform neurofibroma was given, although sarcomatous transformation could not have been entirely excluded from imaging alone. The tumor was subsequently biopsied, and the histopathological analysis confirmed the diagnosis of neurofibroma. This case highlights the importance and diagnostic dilemmas in the presence of this tumor at atypical locations in this disease spectrum.