Colorectal carcinoma is a common lethal disease with signs and symptoms that may be nonspecific. Computed tomography (CT) of the abdomen and pelvis with or without contrast is frequently performed for various general abdominal complaints, but unlike CT colonography, the large bowel may not be optimally prepared for evaluation. As such, careful and diligent assessment of the non-prepared colon in all CT images of the abdomen and pelvis is important, as it ensures that incidental colorectal malignancy is not missed, especially in older patients. This article gives an overview of multidetector CT imaging signs and subtle clues to aid in the diagnosis of colorectal carcinoma, as well as their pitfalls.
Colonic Polyps ; pathology ; Colonography, Computed Tomographic ; Colorectal Neoplasms ; diagnosis ; diagnostic imaging ; Diagnosis, Differential ; Humans ; Incidental Findings ; Pelvis ; diagnostic imaging ; Radiography, Abdominal ; Tomography, X-Ray Computed

Colonic wall thickening is frequently encountered in various conditions, from acute or chronic inflammatory disease to colorectal carcinoma. Colonic wall thickening may be accompanied by calcifications in mucinous adenocarcinoma of the colon, leiomyosarcoma of the colon, schistosomiasis japonica, and phlebosclerotic colitis. Phlebosclerotic colitis is a rare entity of chronic ischemic colitis associated with sclerosis and fibrosis of mesenteric veins. Although its development is usually insidious, and, thus its diagnosis can be delayed, characteristic findings in phlebosclerotic colitis are calcifications of mesenteric veins as well as colonic wall thickening with calcifications. We report on a 71-year-old woman who presented with chronic diarrhea and intermittent hematochezia, who was first misdiagnosed as mucinous adenocarcinoma of the colon, but finally diagnosed as a rare entity of chronic ischemic colitis, phlebosclerotic colitis. Differential points of phlebosclerotic colitis from other diseases, including leiomyosarcoma and schistosomiasis japonica, are also described.
Adenocarcinoma, Mucinous/diagnosis ; Calcinosis/pathology ; Chronic Disease ; Colitis, Ischemic/*diagnosis ; Colonic Neoplasms/diagnosis ; Colonoscopy ; Diagnosis, Differential ; Female ; Humans ; Intestinal Mucosa/pathology ; Mesenteric Veins/pathology ; Radiography, Abdominal ; Sclerosis ; Tomography, X-Ray Computed

Metastasis to the primary thyroid carcinoma is extremely rare. We report here a case of colonic adenocarcinoma metastasis to medullary thyroid carcinoma in a 53-yr old man with a history of colon cancer. He showed a nodular lesion, suggesting malignancy in the thyroid gland, in a follow-up examination after colon cancer surgery. Fine needle aspiration biopsy (FNAB) of the thyroid gland showed tumor cell clusters, which was suspected to be medullary thyroid carcinoma (MTC). The patient underwent a total thyroidectomy. Using several specific immunohistochemical stains, the patient was diagnosed with colonic adenocarcinoma metastasis to MTC. To the best of our knowledge, the present patient is the first case of colonic adenocarcinoma metastasizing to MTC. Although tumor-tumor metastasis to primary thyroid carcinoma is very rare, we still should consider metastasis to the thyroid gland, when a patient with a history of other malignancy presents with a new thyroid finding.
Adenocarcinoma/pathology/surgery ; Biopsy, Fine-Needle ; Carcinoma, Medullary/diagnosis/radiography/*secondary ; Colonic Neoplasms/*pathology/surgery ; Humans ; Male ; Middle Aged ; Neoplasms, Second Primary/*diagnosis ; Thyroid Gland/pathology ; Thyroid Neoplasms/diagnosis/radiography/*secondary ; Thyroid Nodule/diagnosis

BACKGROUND/AIMS: Incidentally detected focal 18F-fluorodeoxyglucose (FDG) uptake was compared with colonoscopy. We investigated the characteristics of colon adenomas which were revealed on PET/CT. Then we identified whether additional colonoscopy was necessary in patients with lesions which were revealed on PET/CT but had no matched lesions on colonoscopy. METHODS: We retrospectively reviewed 95 patients who underwent colonoscopy within a 6 month interval after they had focal FDG uptake from January 2010 to May 2012 at National Police Hospital in Korea. Also, we analyzed 30 patients who underwent additional colonoscopy within 2 years after they had no matched lesions on primary colonoscopy. RESULTS: PET/CT depicted 54.6% (41/75) of adenomas and adenocarcinomas. The PET visibility of colon adenoma was significantly associated with degree of dysplasia (p=0.027), histologic type (p=0.040), and the size (p=0.038). The positivity rate was increased with higher degree of dysplasia (low-grade dysplasia, 47%; high-grade dysplasia, 78%; adenocarcinoma, 100%) and villous patterns of histologic type (tubular, 46.8%; tubulovillous, 87.5%; villous, 100%). Patients with adenomas larger than 10 mm (87.5%) had higher detection rate compared to those with adenomas smaller than 10 mm (49.0%). Among the 30 patients who underwent additional colonoscopy, only one patient had a 6 mm sized tubular adenoma (low-grade dysplasia). CONCLUSIONS: Incidental focal colonic uptake may indicate advanced adenoma or adenocarcinoma. Thus, it justifies performing colonoscopy for identifying the presence of colon neoplasms. However, in case of unmatched lesions between PET/CT and colonoscopy, there was little evidence that additional colonoscopy would yield benefits.
Adenocarcinoma/pathology/radiography/radionuclide imaging ; Adenoma/pathology/radiography/radionuclide imaging ; Adult ; Aged ; Colonic Neoplasms/pathology/*radiography/*radionuclide imaging ; Colonic Polyps/pathology ; Colonoscopy ; Female ; Fluorodeoxyglucose F18/diagnostic use ; Humans ; Male ; Middle Aged ; Multimodal Imaging ; Positron-Emission Tomography ; Radiopharmaceuticals/diagnostic use ; Retrospective Studies ; Tomography, X-Ray Computed

Colorectal cancer is the second most common cancer in males and the fourth most common in females in Korea. Since the most of colorectal cancer occur through the prolonged transformation of adenomas into carcinomas, early detection and removal of colorectal adenomas are one of the most effective methods to prevent colorectal cancer. Considering the increasing incidence of colorectal cancer and polyps in Korea, it is very important to establish Korean guideline for colorectal cancer screening and polyp detection. Korean Multi-Society Take Force developed the guidelines with evidence-based methods. Parts of the statements drawn by systematic reviews and meta-analyses. Herein we discussed the epidemiology of colorectal cancers and adenomas in Korea, optimal screening methods for colorectal cancer, and detection for adenomas including fecal occult blood tests, radiologic tests, and endoscopic examinations.
Adenoma/*diagnosis/epidemiology/radiography ; Age Factors ; Colonic Polyps/pathology ; Colonoscopy ; Colorectal Neoplasms/*diagnosis/epidemiology/radiography ; Databases, Factual ; Early Detection of Cancer ; Female ; Humans ; Immunohistochemistry ; Male ; Occult Blood ; Republic of Korea ; Tomography, X-Ray Computed

Colonic Neoplasms ; pathology ; Colonic Polyps ; pathology ; Fluorodeoxyglucose F18 ; Humans ; Lymphatic Metastasis ; diagnostic imaging ; Male ; Middle Aged ; Positron-Emission Tomography ; Radiography

Neuroendocrine carcinoma of the colon can be classified into small cell carcinoma and large cell neuroendocrine carcinoma. The incidence of neuroendocrine carcinoma is so low that the guideline for the treatment of large cell neuroendocrine carcinoma of the colon are not established. The prognosis of large cell neuroendocrine carcinoma of the colon is worse than that of conventional adenocarcinoma of the colon. We report a case of large cell neuroendocrine carcinoma of the colon that treated with right hemicolectomy and 6th sequential combination chemotherapy of 5-fluorouracil and cisplatin. There has been no evidence of the recurrence or metastasis of tumor for 6 months.
Adult ; Carcinoma, Large Cell/*diagnosis/pathology/radiography ; Carcinoma, Neuroendocrine/*diagnosis/pathology/radiography ; Colonic Neoplasms/*diagnosis/pathology/radiography ; Colonoscopy ; Humans ; Male ; Tomography, X-Ray Computed

Multiple primary malignancy was reported firstly by Billroth in 1889. Recently, multiple primary malignancies are considered to increase due to improved survival rate of cancer patients, advanced diagnostic tools, and increased use of chemotherapy and radiotherapy. In Korea, several cases of triple primary malignancies were reported. However, four primary malignancies in gastro-intestinal tract was rarely reported. Recently, we experienced a 70 year-old male who was diagnosed with metachronous four primary malignancies in rectum, ascending colon, stomach, and ampulla of Vater. We report this rare case of metachronous four primary malignancies with a review of literature.
Adenocarcinoma/*diagnosis/pathology/surgery ; Adenocarcinoma, Mucinous/diagnosis/surgery ; Aged ; Ampulla of Vater/*pathology ; Colonic Neoplasms/diagnosis/surgery ; Common Bile Duct Neoplasms/*diagnosis/pathology/surgery ; Gastrointestinal Neoplasms/*diagnosis/pathology/radiography ; Humans ; Male ; Neoplasms, Second Primary/*diagnosis/pathology ; Rectal Neoplasms/diagnosis/surgery ; Stomach Neoplasms/diagnosis/pathology/surgery ; Tomography, X-Ray Computed

A 70-year-old man with past history of hemicolectomy due to colon cancer underwent a follow-up abdominal/pelvic CT scan. CT revealed a right adrenal metastasis and then he underwent FDG-PET/CT study to search for other possible tumor recurrence. In PET images, other than right adrenal gland, there was an unexpected intense FDG uptake at right inguinal region and at first, it was considered to be an inguinal metastasis. However, correlation of PET images to concurrent CT data revealed it to be a bladder herniation. This case provides an example that analysis of PET images without corresponding CT images can lead to an insufficient interpretation or false positive diagnosis. Hence, radiologists should be aware of the importance of a combined analysis of PET and CT data in the interpretation of integrated PET/CT and rare but intriguing conditions, such as bladder herniation, during the evaluation of PET scans in colon cancer patients.
Abdominal Neoplasms/radionuclide imaging/secondary ; Aged ; Colonic Neoplasms/pathology/radiography/radionuclide imaging ; Diagnosis, Differential ; False Positive Reactions ; Fluorodeoxyglucose F18/*diagnostic use ; Hernia, Inguinal/radiography/*radionuclide imaging ; Humans ; Male ; *Positron-Emission Tomography ; Radiopharmaceuticals/*diagnostic use ; Tomography, X-Ray Computed ; Urinary Bladder Diseases/radiography/*radionuclide imaging

Primary adenosquamous carcinoma of the liver is generally considered as an extremely rare subtype of cholangiocarcinoma. It has been reported mostly in a form of case studies. As far as we know, there was only one case report on tumor related with biliary fistula. Recently, we experienced a case of primary adenosquamous carcinoma of liver with a formation of tumor-colonic fistula. A 54-year-old man was transferred to our hospital due to liver mass detected by abdominal ultrasonogram. Dynamic computed tomogram of liver showed a large irregular hypodense mass without rim enhancement in right lobe of liver and also suggested a fistula formation between the tumor and hepatic flexure of right colon. Colonoscopic examination showed a large colonic wall defect in hepatic flexure and a friable, nodular mucosa around the defected colonic wall. Extended right lobectomy and right hemicolectomy were done. Microscopically, the tumor was composed of squamous cell carcinoma mainly with foci of the adenocarcinoma component.
Carcinoma, Adenosquamous/*pathology/radiography/surgery ; Colonic Diseases/*pathology ; Colonoscopy ; Humans ; Intestinal Fistula/*pathology ; Liver Neoplasms/*pathology/radiography/surgery ; Male ; Middle Aged ; Tomography, X-Ray Computed