Gastrointestinal stromal tumors (GISTs) are unique neoplasms that occur throughout the gastrointestinal tract, mesentery, omentum, and retroperitoneum. They are the most common mesenchymal neoplasm of the gastrointestinal tract and are defined by their expression of KIT (CD117), a tyrosine kinase growth factor receptor. The expression of KIT is important to distinguish GISTs from other mesenchymal neoplasms such as leiomyomas, leiomyosarcomas, schwannomas, and neurofibromas and to determine the appropriateness of KIT-inhibitor therapy. The series described herein was accumulated over 2 years and includes 64 pathologically proved GISTs (28 gastric, 27 small intestinal, six anorectal, one colonic, one esophageal, and one from the small bowel mesentery). Radiologic features of GISTs vary depending on tumor size and organ of origin. Since most GISTs arise within the muscularis propria of the stomach or intestinal wall, they most commonly have an exophytic growth pattern and manifest as dominant masses outside the organ of origin. Dominant intramural and intraluminal masses are less common radiologic manifestations. GISTs occurring in the gastrointestinal tract and mesentery characteristically have hemorrhage, necrosis, or cyst formation that appears as focal areas of low attenuation on computed tomographic images. Although the radiologic features of GISTs are often distinct from those of epithelial tumors, criteria to separate GISTs radiologically from other nonepithelial tumors have not yet been fully developed.

Gastrointestinal stromal tumors: radiologic features with pathologic correlation.

OBJECTIVE. The purpose of our study was to compare the image quality of tomosynthesis with that of conventional mammography and to estimate the recall rate of screening when tomosynthesis is used in addition to mammography.MATERIALS AND METHODS. Women with an abnormal screening mammography were recruited sequentially. Consenting women underwent tomosynthesis of the affected breast corresponding to the views obtained with diagnostic mammography. The study radiologist compared the image quality, including lesion conspicuity and feature analysis, of tomosynthesis with diagnostic film-screen mammography and assessed the need for recall when tomosynthesis was added to digital screening mammography. Screening recalls were considered unnecessary when tomosynthesis did not show a corresponding abnormality or allowed definitely benign lesion characterization. Fisher's exact test was used to determine the association of equivalence and recall status with mammographic finding type.RESULTS. There were 99 digital scre...

Digital breast tomosynthesis: initial experience in 98 women with abnormal digital screening mammography.

PURPOSE: To investigate and describe the anatomic distribution, imaging features, and pattern of metastatic spread of malignant gastrointestinal stromal tumors (GISTs). MATERIALS AND METHODS: The medical records of all patients at our institution with a histologic diagnosis of GIST were reviewed. Two radiologists with knowledge of the diagnosis reviewed the radiologic findings by means of consensus. Sixty-seven patients underwent computed tomography, and scans of the primary tumor were available in 38 patients. RESULTS: One hundred sixteen patients with malignant GISTs were identified (76 men and 40 women; mean age, 54.6 years ± 13.5 [SD]). The primary tumor locations in descending order of frequency were the small bowel (n = 49), stomach (n = 43), colon (n = 7), rectum (n = 6), other (n = 3), and not specified (n = 8). Mean primary tumor size was 13 cm ± 6. Tumors were typically well defined (31 of 36 [86%]), with a heterogeneous rim of soft tissue with lower signal intensity than that of the contrast ma...

Malignant Gastrointestinal Stromal Tumor: Distribution, Imaging Features, and Pattern of Metastatic Spread

The aim of this study was to define the imaging characteristics of primary and recurrent gastrointestinal stromal tumors (GIST) in computed tomography with respect to the tumor size. Computed tomography was performed in 35 patients with histologically confirmed gastrointestinal stromal tumors and analyzed retrospectively by two experienced and independent radiologist. The following morphologic tumor characteristics of primary ( n=20) and ( n=16) recurrent tumors were evaluated according to tumor size, shape, homogeneity, density compared with liver, contrast enhancement, presence of calcifications, ulcerations, fistula or distant metastases and the anatomical relationship to the intestinal wall, and the infiltration of adjacent visceral organs. Small GIST ( 5-10 cm) demonstrated an irregular shape, inhomogeneous density on unenhanced and contrast-enhanced images, a combined intra- and extraluminal tumor growth with aggressive findings, and infiltration of adjacent organs in 9 primary diagnosed and 2 recurrent tumors. Large GIST (>10 cm), which were observed in 8 primary tumors and 11 recurrent tumors, showed an irregular margin with inhomogeneous density and aggressive findings, and were characterized by signs of malignancy such as distant and peritoneal metastases. Small recurrent tumors had a similar appearance as compared with large primary tumors. Computed tomography gives additional information with respect to the relationship of gastrointestinal stromal tumor to the gastrointestinal wall and surrounding organs, and it detects distant metastasis. Primary and recurrent GIST demonstrate characteristic CT imaging features which are related to tumor size. Aggressive findings and signs of malignancy are found in larger tumors and in recurrent disease. Computed tomography is useful in detection and characterization of primary and recurrent tumors with regard to tumor growth pattern, tumor size, and varied appearances of gastrointestinal stromal tumors, and indirectly gives hints regarding dignity and therefore prognostic outcome.

Computed tomography in gastrointestinal stromal tumors

ObjectivesTo assess computed tomography (CT) findings to assist in the distinction of low- and high-grade gastrointestinal stromal tumors (GISTs) and to estimate their relative risk (RR) for mortality.MethodsSixty-nine patients with clinicopathologically and immunohistochemically proven GISTs, inclu

Gastrointestinal stromal tumor. Correlation of computed tomography findings with tumor grade and mortality.

Neoplasms of the small intestine are very rare. Gastrointestinal stromal tumors (GISTs) are one of the new undifferentiated stromal tumors of the gastrointestinal tract diagnosed by immunohistochemistry. We present a case of a malignant GIST arising from the small intestine and report the radiologic characteristics of the tumor and pathological correlation. CT showed a very large, enhancing mass with extensive central necrosis located on the mesenteric side of the jejunum. A perforation into the jejunal lumen was observed by upper GI series. MRI showed a very large tumor which was hypointense on T2-weighted images. Ultrasound revealed a mixed solid and cystic mass. Grossly, the tumor was solid peripherally with extensive central necrosis. Microscopically, it consisted of spindle and epithelioid cells. Immunohistochemically, the cells stained positive for CD34, which is diagnostic of GIST.

Malignant gastrointestinal stromal tumor of the small intestine: radiologic-pathologic correlation.

The aim of this study was to investigate the frequency of breast tumors and breast cancers with noncontrast spiral chest computed tomography (CT). A clinical study was conducted to evaluate findings in the mammary region of 1008 consecutive patients with no mammary symptoms or signs who underwent noncontrast spiral CT of the chest from April 2003 to March 2006. Six cases of breast abnormality were detected among the 1008 women. Three were primary breast cancers, one was metastatic breast cancer, and two were benign tumors. All four breast cancer patients were over 70 years old. The characteristics of the tumor margins on CT scans corresponded to the mammography and ultrasonography findings. The mammographic background density ranged from inhomogeneous high-density breast to fatty breast. The detection rate of primary breast cancer by noncontrast spiral CT was 0.30%. Noncontrast spiral chest CT occasionally detects nonsymptomatic breast cancers, especially in elderly patients.

Detection of incidental breast tumors by noncontrast spiral computed tomography of the chest.

Background

The prognosis for patients with mucosal malignant melanoma (MMM) of the nasal cavity is very poor because of the radioresistance of melanoma cells.



Methods

We present the first case report of the efficacy of superselective intra-arterial cisplatin (CDDP) infusion concurrent with hypofractionated radiotherapy (RT) for MMM of the nasal cavity.



Results

A pink, polypoid mass, histopathologically diagnosed as an amelanostic melanoma, occupied the right nasal cavity. After the treatment, a nasal tumor disappeared, leaving only a small bulge in the medial wall of the middle turbinate. Histopathologic examination revealed scattered degenerated melanoma cells, remaining only in the small restricted area in the medial surface of the excised middle turbinate. Twelve months after the treatment, the patient has not experienced any local recurrence or regional and distant metastasis.



Conclusions

The superselective intra-arterial CDDP infusion concurrent with hypofractionated RT might be useful for the management of nasal MMM. © 2011 Wiley Periodicals, Inc. Head Neck, 2013

Response to intra‐arterial cisplatin and concurrent radiotherapy in a patient with primary mucosal malignant melanoma of the nasal cavity

Low-grade ductal carcinoma in situ (DCIS) arising in a fibroadenoma of the breast during 5 years follow-up: A case report.

A 32-year-old pregnant woman at 29 gestational weeks suffered from the acute onset of severe headache. Brain CT, MRI, and MR angiography (MRA) showed intraventricular and thalamic hemorrhage, ruptured from a thalamic AVM. Based on these findings, conservative treatment was continued until delivery. After cesarean delivery at 34 gestational weeks, conventional cerebral angiography was performed, followed later by gamma-knife therapy. In pregnant patients with suspected cerebrovascular disorders, MRI and MRA should be the first of choice method to evaluate information on the diseased vessels and associated lesions since there is no radiation risk or side effects of contrast medium.

Hiroko Shojaku

Papers

Malignant gastrointestinal stromal tumor of the small intestine: radiologic-pathologic correlation.

Detection of incidental breast tumors by noncontrast spiral computed tomography of the chest.

Response to intra‐arterial cisplatin and concurrent radiotherapy in a patient with primary mucosal malignant melanoma of the nasal cavity

Low-grade ductal carcinoma in situ (DCIS) arising in a fibroadenoma of the breast during 5 years follow-up: A case report.

Use of MR angiography in a pregnant patient with thalamic AVM.