Imaging Findings of Abdominal Extraosseous Plasma Cell Neoplasm

PURPOSE: To evaluate the imaging findings of abdominal extraosseous plasma cell neoplasm. MATERIALS AND METHODS: From April 2000 to January 2005, eight patients (four men, four women; mean age, 50.6 years) with pathologically proved, extraosseous plasma cell neoplasm involving the abdominal organs were included in this study. The diagnoses were based on consensus agreement between two radiologists who retrospectively reviewed CT, ultrasonography, and enteroclysis findings. We evaluated the findings by focusing on the location, size, margin, and enhancement pattern of the lesion, and lymphadenopathy on each image. RESULTS: There were multiple myeloma in four patients and extramedullary plasmacytoma in the remaining four. Involved abdominal organs were the liver (n = 4), spleen (n = 4), lymph node (n = 3), stomach (n = 1), small bowel (n = 1), and colon (n = 1). The hepatic involvement of plasma cell neoplasm presented as a homogeneous, well-defined, solitary mass (n = 1), multiple nodules (n = 1), and hepatomegaly (n = 2). Its involvement of the spleen and lymph node appeared as splenomegaly and lymphadenopathy, respectively. Its involvement of the gastrointestinal tract including the stomach, small bowel, and colon, presented as a homogeneous, diffuse wall thickening or mass in the gastrointestinal tract. CONCLUSION: Abdominal extraosseous plasma cell neoplasm involves occasionally the liver, spleen, and lymph node, and rarely the gastrointestinal tract. When we encounter a well-defined, homogeneous lesion of the abdominal organs in patients diagnosed or suspected as having plasma cell neoplasm, we should consider its involvement of the abdominal organs.

CT Findings of Endometrioma: Differential Points from Other Benign Complex Cystic Adnexal Masses

PURPOSE: To evaluate whether CT scanning is useful in differentiating the between endometriomas and other benign complex cystic adnexal masses, and in determining the method of treatment for each mass lesion. MATERIALS AND METHODS: In 54 cases (47 patients), we retrospectively analysed the CT findings of 20 pathologically-proven twenty endometriomas (bilateral in four cases), eight hemorrhagic functional cysts, two tubal ectopic pregnancies, eight tubo-ovarian abscesses (bilateral in two cases), ten serous cystadenomas (bilateral in one case), and six mucinous cystadenomas. Internal attenuation, the hyperdense portion, adhesion, and cul-de-sac obliteration were evaluated by CT scanning. RESULTS: Fourteen endometriomas (70%) showed a hyperdense portion, and in only two of these (10%), was a focal nodular hyperdense portion seen on pre-contrast CT scan (10% sensitivity, 100% specificity). Partial or complete cul-de-sac obliteration was identified in 11 patients (75%), while hemorrhagic functional cysts showed a hyperdense portion in four cases (50%) and were accompanied by partial cul-de-sac obliteration in two (25%). Two unruptured tubal ectopic pregnancies showed CT findings of unilateral hyperdense cystic masses of more than 60 HU. In all cases, tubo-ovarian abscesses were accompanied by thickening of the uterosacral ligament and deviation of thickened mesosalpinx (anterior deviation in 87.5% of patients). Serous and mucinous cystadenomas showed CT findings of hypodense masses (less than 20 HU) without adhesion or cul-de-sac obliteration, and this was helpful in differentiating cystadenomas from other benign cystic adnexal masses, including endometriomas. CONCLUSION: The evaluation by CT scanning of benign complex cystic adnexal masses with respect to the hyperdense portion and the presence or absence of cul-de-sac obliteration was usful in differentiating endometriomas from other lesions, and might be helpful in determining the method of treatment for each mass lesion.

Differential Diagnosis of Vertebral Lesions with paraspinal Mass with MRI

PURPOSE: To assess the characteristic features of MR findings which would be useful for the differentiation of various spinal diseases involving paraspinal soft tissue mass. MATERIALS AND METHODS: We retrospectively reviewed MR findings in 31 cases(M:F=20:11) of spinal disease in which paraspinal mass was involved. The breakdown of cases was as follows : spinal tuberculosis, 12; spinal metastasis, 13; multiple myeloma, 3; pyogenic spondylitis, 2; spinal aspergillosis; 1. RESULTS: The pattern of bone marrow invasion in spinal metastasis, multiple myeloma, spinal tuberculosis and aspergillosis was mixed ; focal, homogeneously diffuse and inhomogeneously patterns were seen. Pyogenic spondylitis showed inhomogeneously diffuse invasion; an intravertebral abscess was seen in the only five cases of spinal tuberculosis. Vertebral posterior compartment invasion was observed in seven cases of spinal tuberculosis, two of multiple myeloma, the one case of spinal aspergillosis and in all 13 cases of spinal metastasis. This and multiple myeloma showed no disc space invasion, in any case, but all cases of infectious spondylitis showed such invasion. Peripheral rim-enhancement in the paravertebral mass was seen in 11 cases of spinal tuberculosis, one case of pyogenic spondylitis and the case of aspergillosis. Bilobate anterior epidural mass was noted in 60% of spinal tuberculosis cases, 36% of spinal metastasis and one case of pyogenic spondylitis. CONCLUSION: MR findings of spinal disease involving a paraspinal soft tissue mass were useful for differentiation.

CT Findings in Differential Diagnosis of Benign and Malignant Parotid Tumors

PURPOSE: To evaluate CT findings which may help differentiate benign from malignant parotid tumors. MATERIALS AND METHODS: The CT findings of seventy-one cases with surgically-proven parotid tumors were retrospectively analysed for size, location, margin, internal density, adjacent tissue plane and lymphadenopathy. RESULTS: The margin of the mass was smooth and sharp in most benign tumors (89.5%), and irregular or indistinct in twelve which were malignant (75%, p<0.01). With regard to internal density, 70.2% of benign tumors were homogeneous (similar to muscle) and 81.3% of malignant tumors were heterogeneous (p<0.01). When analysing low density patterns within the mass, focal low densities in benign tumors (11/17) and diffuse or scattered multifocal low densities in those which were maligant (8/13) were frequently seen. Three malignant tumors invaded adjacent muscles, the parapharyngeal space, and bones, each in one case, and twelve malignant and one benign tumor infiltrated the adjacent fascia or subcutaneous fat layer. In five patients with a malignant tumor, obliteration by the mass of the fat plane between the mastoid tip and styloid process was noted, suggesting facial nerve invasion, while in three cases of malignancy, lymphadenopathy greater than 1cm was seen. CONCLUSION: In differentiating malignant and benign parotid tumors, the presence of irregular or indistinct margin of the mass, and invasion of adjacent structures, are important. Lymph node enlargement greater than 1cm and diffuse internal low densities, which may suggest necrosis or cystic change were also helpful in differential diagnosis.