Extraosseous multiple myeloma: imaging features.

Multiple myeloma is a disseminated malignant neoplasm usually derived from a single clone of plasma cells. Patients with myeloma have diverse signs such as anemia, hypercalcemia, uremia, pathologic fractures, and recurrent infections. Extraosseous manifestations are found in less than 5% of patients with multiple myeloma. They can arise in any tissue, and their presence has been associated with more aggressive disease. The purpose of this essay is to illustrate the imaging findings of extraosseous myeloma and heighten awareness of this unusual manifestation of multiple myeloma.

Pathways of nodal metastasis in carcinomas of the cecum, ascending colon, and transverse colon: CT demonstration.

The distribution of regional lymph node metastases in carcinomas of the cecum, ascending colon, and transverse colon follows the vascular distribution in the ileocolic mesentery, ascending mesocolon, and transverse mesocolon. The location of these metastatic nodes can be recognized on CT scans when the anatomy of the vessels in the ileocolic mesentery and mesocolon is well understood. This knowledge is important in the preoperative staging of carcinomas of the colon for curative surgery and in the early detection of recurrent nodal disease after curative surgery.

Regional lymph node metastases in carcinoma of the left side of the colon and rectum: CT demonstration.

The distribution of regional lymph node metastases in carcinoma of the left side of the colon, rectum, and anus can be well shown by routine CT of the abdomen and pelvis. Recognition of the location of nodes in the mesocolic, left colic, and IMA nodal groups can help in developing a systematic approach to the detection of nodal metastasis. This can be especially important in preoperative planning for cases in which resection may be curative. In addition, an understanding of the distribution of nodal metastasis will make it possible to recognize early recurrent nodal disease, particularly with an increase in associated increase in levels of carcinoembryonic antigen, and to predict certain clinical sequences such as hydronephrosis of the left kidney associated with left colic nodal metastases.

Primary malignant small round cell tumor of the abdomen: CT findings in five cases.

Malignant small round cell tumor of the abdomen is a newly described clinicopathologic entity. The features of this entity include a predilection for young men, predominant abdominopelvic location, and aggressive behavior. Pathologic analysis demonstrates a small-cell tumor unusually coexpressing desmin and keratin. This study describes CT characteristics in five patients with malignant small round cell tumor of the abdomen. All patients were young white men, 20-36 years old (mean, 28 years). In all five cases, CT scans revealed lobulated masses appearing to arise primarily from peritoneal surfaces and predominantly involving the peritoneal cavity of the abdomen (two cases) and pelvis (two cases); diffuse abdominopelvic involvement was noted in one case. The masses were centrally necrotic and enhanced inhomogeneously after administration of iodinated contrast material. Additional CT features included ascites (one case), calcifications in the dominant mass (one case), omental implants (two cases), hydronephrosis (four cases), anterior diaphragmatic lymphadenopathy (two cases), liver metastases (two cases), and retroperitoneal lymphadenopathy (two cases). CT findings of abdominal malignant small round cell tumor are nonspecific and mimic findings noted in other conditions, such as peritoneal carcinomatosis and leiomyosarcomatosis.