CT appearance of some colonic villous tumors

Giant villous adenoma of the sigmoid colon: an unusual cause of homogeneous, segmental bowel wall thickening

Colonic adenomas are commonly encountered lesions that are a precursor of colorectal cancer. Of these, villous adenomas are a rarer, more advanced subtype that are larger in size than tubular adenomas and have a higher risk of malignant transformation. We present a patient with a giant villous adenoma of the sigmoid colon identified on CT as homogeneous segmental bowel wall thickening.

Three-dimensional computed tomography rendering of pedunculated colon polyp: new "clapper-bell" sign pedunculated polyp at 3D computed tomography

The incidental detection of a tubulovillous adenoma at a contrast-enhanced computed tomography (CECT) with nondedicated protocol, performed in emergency conditions, is an uncommon finding. We report a case of a woman presenting with a subocclusive episode. A CECT scan was performed, and a pedunculated polyp could be appreciated at 3D-reconstruction images. A particular depiction of pedunculus of the polypoid lesion, resemble a clapper-bell, could help to define the vegetating lesion at the volume-rendering reconstruction images. This case emphasizes the fundamental role of postprocessing in the clinical practice to improve the diagnostic accuracy of abdominal CT scan. In addition, a potential new radiologic sign, the "clapper-bell sign", is proposed, as literature about the appearance of a polyp at CECT, performed without a dedicated protocol for colonoscopy, is poor.

Apple-core lesion of the colon: a case report

Introduction

The appearance of the apple-core lesion of the colon can be caused by several diseases.

Case presentation

A male patient was referred to the surgical clinic with melaena and weight loss. Clinical examination and investigations confirmed an apple-core lesion of the colon. He underwent surgery, but unfortunately, died of a chest infection two weeks after the operation.

Conclusion

This case shows the use of computed tomography in demonstrating the primary cause of iron deficiency anaemia, and at the same time, staging the disease for loco-regional metastasis.

Rectal villous tumours: MR features and correlation with TRUS in the preoperative evaluation

AIM

The aim of this study was to assess the clinical relevance of MR and transrectal ultrasonography (TRUS) imaging of rectal villous tumours to elucidate the correlation between imaging results and specific histopathological tumour features, such as tumour size (T) and lymph node involvement (N), in order to establish the better technique for the pre-surgical patient evaluation.

PATIENTS AND METHODS

23 cases of villous tumours of the rectum were studied with phased-array MR and TRUS. All patients underwent either surgical or endoscopic treatment. Final diagnosis was based on histopathological results. In particular, the following features were characterized by the imaging techniques mentioned above: lesion site, distance between lesion and ano-rectal junction, size, morphology and contrast enhancement of lesions, fluid layer around the lesion, alterations of the deep layers of the rectal wall, sphincter infiltration, presence or absence of mesorectal, iliac and obturatory lymphnode involvement.

RESULTS

Histology established muscular involvement in 7 cases (T2), perirectal fat infiltration in 1 case (T3); in the remaining 15 cases, staging was Tis-T1. In 17/23 cases (73.9%) the lesions were correctly staged with both imaging techniques, whereas in 5/23 cases (21.7%) the lesions were overstaged. No cases were understaged. TRUS concorded with histological exams in 17/23 cases (73.9%). 5/23 cases (21.7%) were overstaged and 1/23 (4%) was understaged. MR and TRUS were in accordance in 20/23 cases (86.9%).

DISCUSSION

Considering the frequent degeneration of villous tumours, correct preoperative identification and precise evaluation of these lesions, such as the detection of rectal wall invasion, is essential in deciding optimal treatment strategy. MRI and TRUS allow the identification of specific features of villous tumours and of malignant degeneration, allowing for a correct local disease staging.