Collecting duct carcinoma of the kidney: are imaging findings suggestive of the diagnosis?

OBJECTIVE: Collecting duct carcinoma derives from the renal medulla and has an infiltrative growth pattern at pathologic examination. The purpose of our study was to characterize the imaging features of this aggressive malignancy and determine whether the diagnosis can be reliably suggested from imaging findings. MATERIALS AND METHODS: Radiologic studies from 17 patients with pathologically proven collecting duct carcinoma were analyzed by two reviewers. RESULTS: The tumors varied in size from 1.5 to 19 cm (mean, 7.7 cm). Medullary involvement was present on CT in 16 (94%) of 17 cases, but cortical involvement or an exophytic component was also present in 15 cases (88%) and 10 cases (59%), respectively. The reniform contour of the kidney was preserved in seven cases (41%) and correlated with a smaller tumor size (p<0.01). Tumors showed an infiltrative appearance on CT in 11 cases (65%), but an expansile component was also present in eight of these cases. A cystic component was present on CT in six (35%) of 17 cases. On sonography, the solid tumor component was hyperechoic to normal renal parenchyma in six of seven cases and isoechoic in the other. On MR imaging, all tumors (4/4) were hypointense on T2-weighted imaging. On urography, all lesions (5/5) distorted the intrarenal collecting system. On angiography, all tumors (3/3) were hypovascular. CONCLUSION: Medullary involvement and an infiltrative appearance are common findings on cross-sectional imaging and may suggest the diagnosis of collecting duct carcinoma. In large tumors, however, these features are frequently overshadowed by an exophytic or expansile component that cannot be distinguished from the more common cortical renal cell carcinoma.

Value of barium studies for predicting primary versus secondary non-Hodgkin's gastrointestinal lymphoma.

BACKGROUND: To determine the predictive value of a single lesion versus multifocal disease for differentiating primary and secondary gastrointestinal (GI) lymphoma on barium studies. METHODS: Our study group consisted of 90 cases of non-Hodgkin's GI lymphoma from the radiologic archives of the Armed Forces Institute of Pathology in which barium studies had been performed. Each of those studies was reviewed jointly by two of the authors to determine in a blinded fashion whether the patients had a single lesion or multifocal disease (defined as two or more discrete lesions). Medical and pathologic records were then reviewed to determine whether these patients had primary (defined as lymphoma arising in the GI tract) or secondary (defined as disseminated lymphoma with associated GI tract involvement) GI lymphoma. The final clinical diagnosis was then correlated with the radiographic findings to test the hypothesis that a single lesion is more likely to be associated with primary GI lymphoma and that multifocal disease is more likely to be associated with secondary GI lymphoma. RESULTS: Sixty-eight patients had a single lesion in the GI tract on barium studies; 52 (76%) of these patients had primary GI lymphoma and 16 (24%) had secondary GI lymphoma. Another 22 patients had multifocal disease on barium studies; 20 (91%) of these patients had secondary GI lymphoma and two (9%) had primary GI lymphoma. CONCLUSION: The predictive value of a single lesion for primary GI lymphoma on barium studies was 76%, and the predictive value of multifocal disease for secondary GI lymphoma was 91%. Thus, our data suggest that it is often possible to differentiate these two forms of GI lymphoma on the basis of the radiographic findings.

CT features of Castleman disease of the abdomen and pelvis.

OBJECTIVE: The purpose of this study was to describe the CT features of Castleman disease in the abdomen and pelvis. CONCLUSION: The most frequent appearance of abdominal or pelvic Castleman disease is of a single, well-defined enhancing mass. Smaller tumors (<5 cm) display homogeneous contrast enhancement; larger tumors (>5 cm) show heterogeneous enhancement and attenuation when correlated with central necrosis and degeneration. Calcification was seen in 31% of the cases. Castleman disease may be considered in the differential diagnosis of a discrete enhancing mass in the abdomen or pelvis.

Fibrolamellar carcinoma of the liver: radiologic-pathologic correlation.

Fibrolamellar carcinoma is a malignant hepatocellular tumor with distinct clinical and pathologic differences from hepatocellular carcinoma. It differs from hepatocellular carcinoma in demographics, condition of the affected liver, tumor markers, and prognosis. Fibrolamellar carcinoma characteristically manifests as a large hepatic mass in adolescents or young adults (without gender predominance). Cirrhosis; elevated alpha-fetoprotein levels; and typical risk factors for hepatocellular carcinoma such as viral hepatitis, alcohol abuse, and metabolic disease are typically absent. Fibrolamellar carcinoma is characterized pathologically by cords of tumor cells surrounded by abundant collagenous fibrous tissue arranged in a parallel or lamellar distribution. Fibrotic lamellae often coalesce to form a central scar. Fibrolamellar carcinoma characteristically appears on radiologic images as a lobulated heterogeneous mass with a central scar in an otherwise normal liver. Radiologic evidence of cirrhosis, vascular invasion, or multifocal disease--findings typical of hepatocellular carcinoma--is uncommon in fibrolamellar carcinoma. Imaging features of fibrolamellar carcinoma overlap with those of other scar-producing lesions including focal nodular hyperplasia (FNH), hepatocellular adenoma and carcinoma, hemangioma, metastases, and cholangiocarcinoma. FNH, in particular, may simulate fibrolamellar carcinoma, since both have similar demographic and clinical characteristics. Because some believe that radiologic diagnosis of FNH is possible, it is important to understand the imaging appearance of fibrolamellar carcinoma to avoid misdiagnosing this malignant tumor as a FNH.

Sex cord-stromal and steroid cell tumors of the ovary.

Gonadal cell types that derive from the coelomic epithelium (sex cords) or mesenchymal cells of the embryonic gonads include granulosa cells, theca cells, fibroblasts, Leydig cells, and Sertoli cells. Ovarian tumors of these cell types are called sex cord-stromal tumors. This group of tumors represents approximately 8% of ovarian neoplasms and affects all age groups. The more common types are granulosa cell tumors (GCTs), fibrothecomas, and Sertoli-Leydig cell tumors. Sex cord-stromal tumors are of interest partly because of their hormonal effects, which are rare for other ovarian neoplasms. These effects include estrogenic effects (pseudoprecocious puberty, endometrial bleeding, endometrial hyperplasia and carcinoma) and virilization. The variety of gross appearances of these tumors, ranging from large multicystic masses to small solid masses, would appear to preclude a specific radiologic diagnosis. However, in many patients, both clinical and radiologic clues can suggest the diagnosis, including predominantly fibrous content at ultrasound or magnetic resonance imaging (fibrothecoma), large hemorrhagic multicystic mass in a child with pseudoprecocious puberty (juvenile GCT), and associated syndromes such as Peutz-Jeghers syndrome (sex cord tumor with annular tubules) or Ollier disease and Maffucci syndrome (juvenile GCT).

Primary malignant melanoma of the esophagus: radiographic findings in seven patients.

PURPOSE: To evaluate the radiographic findings in a series of patients with primary malignant melanoma of the esophagus. MATERIALS AND METHODS: Seven cases of primary esophageal melanoma were collected from the Hospital of the University of Pennsylvania and the radiologic archives of the Armed Forces Institute of Pathology. All patients underwent esophagography (double-contrast esophagograms in four patients, single-contrast esophagograms in three patients). Medical, endoscopic, and pathology reports were also reviewed. RESULTS: Six patients presented with dysphagia (average duration, 5 months). The remaining patient had recent onset of melena. In all patients, barium studies revealed bulky, polypoid intraluminal masses that focally expanded the esophagus without causing obstruction. The tumors were located in the distal third of the thoracic esophagus in four patients, the middle third in two, and the proximal third in one. Tumor pigmentation was noted at endoscopy in only one patient. All patients underwent extensive esophageal resection. Of four patients with clinical follow-up findings, two were alive and well 2 and 6 months after surgery; the other two had metastases to the lung and liver within 2 months of surgery. CONCLUSION: Primary esophageal melanomas have strikingly similar barium study findings, appearing as bulky, polypoid intraluminal masses that focally expand the esophagus without causing obstruction. Despite its rarity, primary esophageal melanoma should be considered when characteristic findings are present on barium studies.