Unusual lymphoproliferative disorders in nine adults with HIV or AIDS: CT and pathologic findings.

PURPOSE: To identify characteristic computed tomographic (CT) findings in unusual pulmonary lymphoproliferative disorders seen in adults with the human immunodeficiency virus (HIV) or acquired immunodeficiency syndrome (AIDS). MATERIALS AND METHODS: The authors retrospectively reviewed the CT scans and pathologic specimens from nine patients with pulmonary lymphoproliferative disorders. CT scans were evaluated for nodules, reticulation, areas of ground-glass attenuation, consolidation, and bronchial disease. Changes seen in pathologic specimens were classified as consistent with classic lymphocytic interstitial pneumonitis (LIP), mucosa-associated lymphoid tissue lymphoma (MALTOMA), or atypical lymphoproliferative disorder (ALD). Immunopathologic results were reviewed when available. RESULTS: Eight patients had AIDS. Five patients had classic LIP. One patient had MALTOMA, and three patients had ALD. Altogether, 2-4-mm-diameter nodules were the predominant CT finding in eight patients; these were peribronchovascular in four patients. The presence of interstitial nodules correlated with the pathologic finding of nodular disease in seven patients. CONCLUSION: Familiarity with these AIDS-related disorders and their CT appearance should assist in the differential diagnosis.

Observations on the growth of renal neoplasms.

A retrospective review of the imaging results of 11 patients with 13 solid renal parenchymal neoplasms was performed, allowing analysis of the linear growth rates of these tumors. The study sample included seven pathologically proved renal adenocarcinomas and six lesions that were indicative of a neoplasm radiologically (enhancing parenchymal mass on computed tomographic [CT] scans with documented interval growth), which were followed up for 2-7.8 years. Variable interval tumor growth was demonstrated in every case except one and ranged from 0 to 1.6 cm/y, with an overall mean linear growth rate of approximately 0.5 cm/y. Ten of 11 "small renal neoplasms" (less than or equal to 3.0 cm in diameter) displayed interval growth, with five ultimately measuring greater than 3.0 cm (size range, 3.5-7.0 cm). While the results are preliminary and reflect observations on a very small study sample, it was noted that five of the seven pathologically proved adenocarcinomas appeared homogeneous and well marginated, and all were low-grade, low-stage carcinomas. These grew more slowly and were generally smaller at initial presentation than higher-grade lesions, which demonstrated a more heterogeneous appearance on CT scans.

Definitive diagnosis of hepatic hemangiomas: MR imaging versus Tc-99m-labeled red blood cell SPECT.

Thirty-seven patients with 69 suspected hemangiomas found by means of computed tomography (CT) and/or ultrasound were studied with both 0.5-T magnetic resonance (MR) imaging and single photon emission CT (SPECT) with technetium-99m-labeled red blood cells. Using a criterion of "perfusion-blood pool mismatch," SPECT readers diagnosed 50 of 64 hemangiomas and all five "nonhemangiomas" (sensitivity, 78% [95% confidence interval, 0.664 - 0.864]; accuracy, 80% [0.69 - 0.877]). Qualitative analysis of lesion signal intensity on T2-weighted spin-echo MR images allowed readers to diagnose 58 of 64 hemangiomas and four of five nonhemangiomas (sensitivity, 91% [0.814 - 0.96]; accuracy, 90% [0.807 - 0.951]). Because of the significantly higher cost of MR imaging and its inability to categorically differentiate hemangiomas from hypervascular metastases, the authors consider SPECT to be the method of choice for diagnosing hepatic hemangiomas. MR imaging should be reserved for the diagnosis of lesions smaller than 2.0 cm and for those 2.5 cm and smaller adjacent to the heart or major hepatic vessels; in such cases MR imaging was found superior to SPECT.

Magnetic resonance imaging of the kidneys and adrenals.

Renal and adrenal anatomy, both normal and abnormal, are well depicted by MRI. Although MRI is not a sensitive modality for detection of renal cell carcinoma, it has clinical utility for evaluation of vascular involvement or direct extension of neoplasm into adjacent organs when CT findings are equivocal. Use of signal characteristics has not been useful in differentiating simple from complex cystic renal masses or among the various causes of medical renal disease and renal transplant failure. Similarly, signal characteristics are not sufficiently reliable for differentiating benign from malignant adrenal masses. MRI is useful, however, for detection and localization of pheochromocytomas. MRI plays a major role in imaging of children with neuroblastoma and Wilms' tumor and may obviate other, often more invasive, examinations in these cases.

Extrapulmonary Pneumocystis carinii infection in AIDS: CT findings.

Clinical and computed tomographic (CT) findings in three cases of extrapulmonary Pneumocystis carinii infection in patients with acquired immunodeficiency syndrome (AIDS) were reviewed. Proved sites of involvement included the spleen (n = 2), bone marrow (n = 1), liver (n = 1), and peritoneal and pleural fluid (n = 1). CT findings included focal low-attenuation splenic lesions that became progressively calcified in rimlike or punctate fashion; punctate calcifications in the liver, renal cortices, and adrenal glands; calcification of lymph nodes; and pleural and peritoneal effusions with subsequent calcifications of the pleural and peritoneal surfaces. Although rare both before and since the onset of the AIDS epidemic, extrapulmonary P carinii infection in AIDS patients has been reported with increasing frequency in recent years, and more cases with radiologic manifestations should be expected.

Septic pulmonary emboli: CT-radiographic correlation.

Radiographic and CT findings in 15 patients with clinically documented septic pulmonary emboli were compared retrospectively. In most cases, radiographic changes were nonspecific. In comparison, on CT a combination of specific signs could be identified in all patients. These included peripheral nodules with clearly identifiable feeding vessels associated with metastatic lung abscesses (10 [67%] of 15 cases), and subpleural, wedge-shaped densities with and without necrosis caused by septic infarcts (11 [73%] of 15 cases). Ancillary pleural, mediastinal, axillary, and pericardial abnormalities also were more easily identified with CT. We conclude that CT is complementary to other imaging techniques in the recognition of septic pulmonary emboli.

Sonography of the simple and complicated ipsilateral fused kidney.

Anomalies of renal fusion and their sonographic findings can be straightforward or quite complex. Sonograms of eight cases of simple and complicated anomalies of renal fusion in pediatric patients are reviewed to determine characteristic sonographic findings in such cases. The correct diagnosis can be suspected by evaluation of the following parameters: (1) the echoic texture of the renal "mass"; (2) the differential orientation of the renal pelves; (3) the content of the contralateral renal fossa; (4) the size of the ipsilateral kidney; (5) extension of the isthmus medially anterior to the spine; and (6) presence of a deep anteroposterior notch. Utilizing these parameters, a rationale for diagnosis and for selecting the appropriate sequence of further studies is suggested.

The current role of computerized tomography in inflammatory disease of the bowel.

CT has had a major and still evolving role in the diagnosis and management of inflammatory diseases of the bowel. The advantages of CT over conventional contrast examinations in these conditions include direct visualization of the bowel wall, detection of extramural disease, definition of the type and severity of such disease, visualization of all of the abdominal structures in one examination, and the noninvasive nature of the procedure. The current role of CT in diagnosis and management of these disorders varies. In diverticulitis, we believe CT should be used as the primary method of investigation, as well as for evaluation of complications. If surgical resection is not contemplated, the CT diagnosis should be confirmed by CE. In most cases of appendicitis, the diagnosis is still most accurately made clinically; radiographic evaluation should be reserved for cases with atypical clinical presentations. We advocate the use of CT as the first diagnostic procedure in these patients; if CT does not offer conclusive evidence of the diagnosis, contrast enema can be performed. In Crohn's disease, conventional barium studies remain the examinations of choice for diagnosis; CT should be used to evaluate possible complications and as a guide for proper management. Inflammatory colitides other than Crohn's disease primarily affect the mucosa, and are therefore best evaluated by barium enema; CT offers little additional information in these disorders. In all cases, conventional contrast studies and CT should be considered complimentary rather than exclusive procedures. In difficult cases, both examinations may be needed for complete evaluation.

"Supernormal" bone image in a case of Waldenström macroglobulinemia.

A case of Waldenström macroglobulinemia, a rare cause of diffusely increased skeletal uptake and relatively diminished renal uptake of bone seeking radiopharmaceutical, is presented. This pattern has been described in a variety of disorders. An important observation to be made in these cases is the skeletal distribution of the radiopharmaceutical. In diffuse bone metastases from carcinoma, which is the most common cause of these findings, the increased activity is primarily in the axial skeleton. In some of the more uncommon causes, including certain hematologic disorders, however, the increased skeletal uptake is more homogeneous in distribution, with prominent uptake in the skull and distal extremities.

An unusual case of malignant melanoma of the small intestine.

A 42-year-old woman presented with abdominal pain and diarrhea. Small bowel x-rays and endoscopy revealed a diffuse, infiltrating lesion of the small intestine, which on biopsy proved to be melanoma diffusely infiltrating the lamina propria. Because of marked hypoalbuminemia, protein-losing enteropathy was suspected. This is an unusual case, because melanoma of the small intestine usually does not produce diffuse involvement.