Cross-Sectional Imaging of Small Bowel Malignancies

CT features of gastrointestinal spindle cell, epithelial, and round cell tumors in 41 dogs

There is sparse published information on computed tomographic (CT) characteristics of canine gastrointestinal tumors. The purposes of this multi-center, retrospective, descriptive study were to describe the CT features of histologically-confirmed canine gastrointestinal spindle cell, epithelial, and round cell tumors and, when available, describe the corresponding ultrasound findings. The inclusion criteria were as follows: availability of pre-and post-contrast CT study, and a histopathological diagnosis of the lesions. Recorded parameters were tumor size, location, gastrointestinal wall layers involvement, lesion's growth and enhancement patterns, tumor margination, presence of stenosis, mineralization, ulcerations, lymphadenopathy, or other lesions in the abdomen/thorax. When available, ultrasound images were evaluated. Forty-one dogs met the inclusion criteria and had the following histological diagnoses: 21/41 (51%) spindle cells (7 leiomyomas, 14 leiomyosarcomas/gastrointestinal stromal tumors (GISTs)), 13/41 (32%) epithelial (adenocarcinoma), and 7/41 (17%) round cell (lymphoma) tumors. The growth pattern was concentric, eccentric, and mixed in epithelial, spindle cell, and round cell tumors, respectively. Spindle cell tumors had the largest main volume and involved the outer gastrointestinal layer with an unaffected inner layer. Leiomyosarcomas/GISTs showed irregular margins compared to leiomyomas. Only lymphomas showed multifocal gastrointestinal involvement. Nine carcinomas and six spindle cell tumors caused partial stenosis with secondary sub-obstruction. Mineralizations were more frequent in spindle cell tumors (10/21) and absent in lymphomas. Lymphadenomegaly was widespread in lymphomas, regional in leiomyosarcomas-GISTs and adenocarcinomas, and absent in leiomyomas. The reported CT features may be useful in prioritizing the differential diagnosis between spindle cell, epithelial, and round cell tumors, similar to those reported on ultrasound.

Preliminary study of CT features of intermediate- and high-grade alimentary lymphoma and adenocarcinoma in cats

CASE SERIES SUMMARY

The ultrasonographic findings of many feline intestinal tumours are similar. This study evaluated the CT features of intermediate- and high-grade alimentary lymphoma and adenocarcinoma in cats. CT was performed on six cats with adenocarcinoma and 14 cats with lymphoma. Comparisons between tumour types were conducted, focusing on CT features, including obstruction (present or absent), growth patterns of lesions (symmetry or asymmetry), layering enhancement (present or absent), location of the lesion, number of lesions (solitary or multiple), lymphadenopathy (present or absent), location of lymphadenopathy, pulmonary metastasis (present or absent) and maximum thickness (mm) of the lesion. The cats with adenocarcinoma (n = 5/6 [83%]) experienced intestinal obstruction significantly more often than cats with lymphoma (n = 0/14 [0%]; P = 0.0004). Layering enhancement was observed significantly more often in cats with adenocarcinoma (n = 6/6 [100%]) than in cats with lymphoma (n = 1/14 [7%]; P = 0.0002). Lymphadenopathy was detected significantly more often in cats with lymphoma (n = 14/14 [100%]) than in cats with adenocarcinoma (n = 2/6 [33%]) (P = 0.003). In cats with lymphoma, the intestine (12.1 ± 3.9 mm) was significantly thicker than that in cats with adenocarcinoma (6.4 ± 2.3 mm; P = 0.005).

RELEVANCE AND NOVEL INFORMATION

To the best of our knowledge, no reports have described the characteristics of feline intestinal tumours using CT. Layering enhancement was observed in cats with intestinal adenocarcinomas. No layering enhancement was observed in alimentary lymphoma in cats, but enlarged regional nodes were noted. Lesions with lymphoma were thicker than those with adenocarcinoma. These findings may help differentiate between adenocarcinomas and lymphomas.

Small Bowel Obstruction Caused by Small Intestinal Metastasis Secondary to Esophageal Carcinoma

Despite the frequent rapid spread of esophageal cancers to other organs, metastases to the small intestine are uncommon. As such, this paper describes a case of a 60-year-old male who developed a small intestinal obstruction due to metastasis from esophageal carcinoma. This patient had received radical esophagectomy for esophageal carcinoma 14 months prior to the diagnosis. Furthermore, the important role of computed tomography scans played in composing the differential diagnosis will be explored. In order to relieve the obstruction, resection of the small intestine was performed, and the patient survived six months postoperatively.

Systemic manifestations - do not forget the small bowel

PURPOSE OF REVIEW

Systemic diseases can afflict the small bowel (SB) but be challenging to diagnose. In this review, we aim to provide a broad overview of these conditions and to summarise their management.

RECENT FINDINGS

Small bowel capsule endoscopy (SBCE) is an important modality to investigate pathology in the SB. SB imaging can be complementary to SBCE for mural and extramural involvement and detection of multiorgan involvement or lymphadenopathy. Device assisted enteroscopy provides a therapeutic arm, to SBCE enabling histology and therapeutics to be carried out.

SUMMARY

SB endoscopy is essential in the diagnosis, management and monitoring of these multi-system conditions. Collaboration across SB centres to combine experience will help to improve the management of some of these rarer SB conditions.

Imaging of the small bowel: a review of current practice

This article summarises radiological imaging of the small bowel, with an emphasis on Crohn's disease. Different imaging techniques are discussed, including the advantages and disadvantages of each modality, and radiological findings for common small bowel pathologies are described, supplemented with pictorial examples.

CT detection of primary and metastatic ileal carcinoid tumor: rates of missed findings and associated delay in clinical diagnosis

PURPOSE

To determine the rate of missed CT findings of ileal carcinoid tumor prior to pathologic diagnosis and the resultant diagnostic delay.

METHODS

Initially, 74 patients with abdominal and pelvic CT prior to pathologically-proven diagnosis of ileal carcinoid were identified. Patients were excluded when the original CT study (n = 6) or report (n = 4) was not available, resulting in a final cohort of 64 patients (mean age, 58.3 years; 29 M/35F); 27 (42%) patients had more than one abdominal CT prior to diagnosis. All available CT studies prior to diagnosis were retrospectively reviewed for the presence of the primary ileal tumor and metastatic disease (mesenteric and hepatic).

RESULTS

Primary ileal tumors were prospectively missed on at least one CT scan in 64% (32/50) of patients with retrospectively identifiable disease. CT findings of mesenteric spread were missed at least once in 46% (25/54) of cases where present in retrospect. By the final pre-operative CT, hepatic metastases and bowel wall thickening were present in 55% (35/64) and 52% (33/64) of cases, respectively. In patients with missed ileal and/or mesenteric findings resulting in diagnostic delay, mean delay was 40 months (range 4-98 months).

CONCLUSION

Initial presentation of ileal carcinoid tumor, even with mesenteric involvement, is often missed prospectively at abdominal CT, leading to delay in diagnosis until bowel or mesenteric findings become more obvious, or hepatic metastatic disease manifests. Radiologists should make a concerted effort to evaluate the bowel and mesentery in patients with long-standing vague abdominal symptoms.

An Overt, Obscure Gastrointestinal Bleed Caused by a Primary Small Bowel Fibroblastic Reticular Cell Sarcoma

Small bowel bleeding should be considered in patients who continue to bleed despite a negative upper endoscopy and colonoscopy. The differential diagnosis of small bowel bleeding can include infection, inflammatory conditions, vascular malformations, and, rarely, malignancy. This report demonstrates a rare, primary, small bowel, reticular cell sarcoma presenting as an overt gastrointestinal bleed. These tumors are difficult to diagnose because they are rarely seen on traditional cross-sectional imaging and can present with multiple synchronous lesions throughout the intestinal tract.

Multidetector CT enterography of focal small bowel lesions: a radiological-pathological correlation

Focal small bowel lesions present a diagnostic challenge for both the radiologist and gastroenterologist. Both the detection and characterization of small bowel masses have greatly improved with the advent of multidetector CT enterography (MD-CTE). As such, MD-CTE is increasingly utilized in the workup of occult gastrointestinal bleeding. In this article, we review the spectrum of focal small bowel masses with pathologic correlation. Adenocarcinoma, the most common primary small bowel malignancy, presents as a focal irregular mass occasionally with circumferential extension leading to obstruction. Small bowel carcinoid tumors most commonly arise in the ileum and are characterized by avid enhancement and marked desmoplastic response of metastatic lesions. Aneurysmal dilatation of small bowel is pathognomonic for lymphoma and secondary findings of lymphadenopathy and splenomegaly should be sought. Benign small bowel masses such as leiomyoma and adenoma may be responsible for occult gastrointestinal bleeding. However, primary vascular lesions of the small bowel remain the most common cause for occult small bowel gastrointestinal bleeding. The arterial phase of contrast obtained with CTE aids in recognition of the vascular nature of these lesions. Systemic conditions such as Peutz-Jeghers syndrome and Crohn's disease may be suggested by the presence of multiple small bowel lesions. Lastly, potential pitfalls such as ingested material should be considered when faced with focal small bowel masses.

Transcatheter Arterial Embolization for Gastrointestinal Bleeding Secondary to Gastrointestinal Lymphoma

PURPOSE

To evaluate the effectiveness of transcatheter arterial embolization (TAE) for gastrointestinal (GI) bleeding caused by GI lymphoma.

MATERIALS AND METHODS

The medical records of 11 patients who underwent TAE for GI bleeding caused by GI lymphoma between 2001 and 2015 were reviewed retrospectively.

RESULTS

A total of 20 TAE procedures were performed. On angiography, contrast extravasation, and both contrast extravasation and tumor staining were seen in 95 % (19/20) and 5 % (1/20) of the procedures, respectively. The most frequently embolized arteries were jejunal (n = 13) and ileal (n = 5) branches. Technical and clinical success rates were 100 % (20/20) and 27 % (3/11), respectively. The causes of clinical failure in eight patients were rebleeding at new sites. In four patients who underwent repeat angiography, the bleeding focus was new each time. Three patients underwent small bowel resection due to rebleeding after one (n = 2) or four (n = 1) times of TAEs. Another two patients underwent small bowel resection due to small bowel ischemia/perforation after three or four times of TAEs. The 30-day mortality rate was 18 % due to hypovolemic shock (n = 1) and multiorgan failure (n = 1).

CONCLUSION

Angiogram with TAE shows limited therapeutic efficacy to manage GI lymphoma-related bleeding due to high rebleeding at new sites. Although TAE can be an initial hemostatic measure, surgery should be considered for rebleeding due to possible bowel ischemic complication after repeated TAE procedures.

Imaging of primary gastrointestinal lymphoma

Primary gastrointestinal (GI) lymphoma most often arises from stomach, small bowel, or colon. The 2 most common subtypes of primary GI lymphoma include low-grade mucosa-associated lymphoid tissue lymphoma, strongly associated with Helicobacter pylori infection, and high-grade diffuse, large B-cell lymphoma. Primary GI lymphoma demonstrates a myriad of imaging manifestations that can commonly mimic other pathologies. Timely and accurate diagnosis remains important because treatment and prognosis of primary GI lymphoma differ significantly from other GI malignancies and even lymphoma of other primary sites.