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Biomedical subjects

D G Varma

Publications and source records attributed to D G Varma.

At least 19 recordsLinked to original sources

Chondrosarcoma: MR imaging with pathologic correlation.

Magnetic resonance (MR) images of 21 surgically confirmed chondrosarcomas were retrospectively reviewed in conjunction with plain radiographs and computed tomographic scans and correlated with pathologic findings. The tumors appeared lobulated, and signal intensity, as analyzed visually (intermediate on T1-weighted, high on T2-weighted images), was similar for all lesions, regardless of pathologic type. Size of lesion was not an indicator of grade. The appearances of mesenchymal and dedifferentiated chondrosarcomas mimicked that of conventional chondrosarcoma. Extraskeletal chondrosarcoma was visualized as a lobulated soft-tissue mass. In all cases, MR imaging accurately depicted intraosseous and soft-tissue extent of tumor noted at surgery and pathologic examination. Histologic type or grade of chondrosarcoma generally cannot be characterized on the basis of visual analysis of signal intensity noted on routine MR images. However, MR imaging is excellent for exact delineation of tumor extent.

Bone Neoplasms

Multiple myeloma: spinal MR imaging in patients with untreated newly diagnosed disease.

Spinal magnetic resonance (MR) imaging was performed in 29 patients with newly diagnosed, untreated multiple myeloma. Nineteen (66%) patients were asymptomatic. Sagittal pre- and postcontrast T1-weighted spin-echo images and gradient-recalled-echo images of the thoracic and lumbosacral spine were obtained. Marrow involvement was identified in 20 (69%) patients. There were three MR patterns: focal lesions in nine patients (31%), diffuse involvement in seven (24%), and an inhomogeneous pattern of tiny lesions on a background of normal marrow in four (14%). A statistically significant correlation between MR imaging patterns of marrow involvement and serum hemoglobin values (one-way, P = .0899; Kruskal-Wallis, P = .0620) and between MR imaging patterns and percentage of marrow plasmacytosis (Kruskal-Wallis, P = .0314) was noted, with patterns of diffuse and focal marrow involvement associated with more abnormal values. Spinal MR imaging in patients with early myeloma may reveal marrow involvement in both symptomatic and asymptomatic patients. Some correlation was found between MR imaging patterns and laboratory indexes of disease.

Adult

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.

Abdominal Neoplasms

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.

Anus Neoplasms

Case report 682. Neuroepithelioma of soft tissues of the knee.

Peripheral neuroepitheliomas should be included in the differential diagnosis of a soft-tissue tumor in the extremities or chest wall, especially in young adolescents. MRI provides useful information as to the extent of the tumor and relationship with adjacent structures, although it may not differentiate neuroepitheliomas from other, more common, soft-tissue sarcomas. Together with clinical and histological findings, MRI can assist in the diagnosis and treatment planning of this tumor.

Adolescent

MR appearance of the distended iliopsoas bursa.

The purpose of this essay is to illustrate the MR appearance of the distended iliopsoas bursa. The bursa must be recognized on MR scans to avoid confusing it with malignant neoplasms and other lesions.

Aged

Soft-tissue sarcoma: MR imaging vs sonography for detection of local recurrence after surgery.

To determine the value of MR and sonography in detecting local recurrences of soft-tissue sarcomas after surgery, 26 MR and sonographic studies performed in 21 patients were reviewed retrospectively. Recurrences were confirmed histologically in 12 (46%) of 26 studies. The MR images and sonograms were obtained within 1 month of each other. The findings were classified as recurrence, no recurrence, or indeterminate. Sonography was instrumental in guiding fine-needle aspiration biopsy of impalpable lesions. In two cases, the findings on sonography were indeterminate. In both of these cases, the sonograms had been obtained soon after surgery (at 2 and 4 months). The sensitivity and specificity in the detection of local recurrences were 83% and 93%, respectively, for MR and 100% and 79%, respectively, for sonography. These differences were not statistically significant. We conclude that MR and sonography appear to be equally useful in the detection of local recurrences of soft-tissue sarcomas, sonography can be used for routine follow-up and in guiding needle biopsies, sonography may be more difficult to interpret than MR during the early postoperative period, and MR should be used if sonography is inconclusive.

Adolescent

Computed tomography of gangrenous acute postoperative acalculous cholecystitis.

The computed tomographic findings in a case of complicated acute cholecystitis after surgery unrelated to the biliary tree are described. Postoperative cholecystitis is associated with high morbidity and mortality, and early diagnosis by appropriate imaging modalities and prompt surgical intervention is essential in the successful management of this complication.

Acute Disease

Unusual cause of gastric outlet obstruction: CT findings in Bouveret's syndrome.

We have described an 81-year-old woman with symptoms of gastric outlet obstruction in whom upper gastrointestinal endoscopy showed an extrinsic mass compressing the superior aspect of the postbulbar duodenum. This was confirmed by an upper gastrointestinal series, and CT revealed migration of a known, previously asymptomatic gallstone through the duodenal wall, forming a cholecystoduodenal fistula.

Aged

Computed tomography of infiltrating benign lipoma.

Lipomas are frequently encountered benign tumors of adipose tissue origin. A lipoma generally develops in the superficial subcutaneous tissues but may occasionally be deep seated, growing between or within muscles. Deep-seated lipomas (excluding body cavities and viscera) have been termed infiltrating benign lipomas, of which there are two varieties--lipoma and angiolipoma. We wish to report three cases of infiltrating benign lipomas. Computed tomography scanning is the diagnostic modality of choice in the evaluation of these tumors.

Aged

Pathologic fractures in a patient with renal osteodystrophy. Failure of early detection on bone scans.

A case of false-negative Tc-99m MDP bone scintigrams, taken at one and two weeks for pathologic fractures in a patient with metabolic bone disease and a super-scan appearance, is described. The patient had renal osteodystrophy, and postparathyroidectomy hypocalcemia. Postoperative seizures caused multiple pathologic fractures. Initial scans were negative for focal tracer localization in the presence of a continued super-scan appearance. After months of calcium and vitamin D replacement therapy, fracture sites became positive on Tc-99m MDP imaging. The observations in this case lend credence to the hypothesis of Tc-99m MDP binding by immature collagen in the production of a super scan in metabolic bone disease, as well as that of Tc-99m MDP chemisorption to calcium hydroxyapatite crystal in fracture healing. In addition, aluminum toxicity, common in chronic renal osteodystrophy, may have played a role in the delayed fracture healing.

Adult