David H. Stephens

Renal Cell Carcinoma Metastatic to the Pancreas: Clinical and Radiological Features

OBJECTIVE To review the clinical features, computed tomographic (CT) appearance, and treatment outcomes in a case series of patients with renal cell carcinoma (RCC) metastatic to the pancreas. PATIENTS AND METHODS We retrospectively reviewed the records of 23 patients (15 men and 8 women) with RCC metastatic to the pancreas, detected by CT examination between 1986 and 1996. All patients had undergone a previous nephrectomy for RCC. RESULTS Isolated mild elevation in liver function test results (in 5 patients) or in serum amylase level (in 8 patients) was observed. New-onset diabetes was detected in 3 patients. The CT characteristics of the pancreatic metastases generally resembled those of primary RCC with well-defined margins and greater enhancement than normal pancreas with a central area of low attenuation. The mean interval between resection of the primary RCC and detection of the pancreatic metastases was 116 months (range, 1-295 months). In 18 patients (78%), the pancreatic metastases were diagnosed more than 5 years after nephrectomy. The pancreas was the initial metastatic site in 12 patients (52%). Survival was shortened with higher tumor grade (mean survival time of 41 months and 10 months in patients with grade 2 and 3, respectively). Surgical resection was carried out in 11 patients (7 distal and 3 total pancreatectomies and 1 distal pancreatectomy followed 4 years later by total pancreatectomy), with 8 patients alive at a mean follow-up of 4 years, 6 of whom remained free of recurrence. Overall, 12 patients (52%) were alive at a mean of 42 months after diagnosis of metastatic disease. CONCLUSIONS The appearance of metastatic RCC lesions in the pancreas closely resembles the appearance of primary RCC on CT images. Pancreatic metastases from RCC are frequently detected many years after nephrectomy. Patient survival correlates with tumor grade. Histologic analysis of pancreatic masses in patients with a history of resected primary RCC is important since the prognosis for RCC metastatic to the pancreas is much better than that for primary pancreatic adenocarcinoma.

Mosaic pattern of hepatocellular carcinoma : Histologic basis for a characteristic CT appearance

PURPOSE The mosaic pattern is a characteristic CT appearance for hepatocellular carcinoma (HCC). This study was designed to assess the tissue composition responsible for the CT mosaic pattern. METHOD Gross and whole-mount histologic sections of 10 HCC tumors from eight patients were prepared at identical levels as preoperative CT sections. CT features of the mosaic tumor pattern were spatially registered with the corresponding pathologic sections. RESULTS CT of mosaic HCC demonstrated enhancing nodules (9/10), low attenuation areas (9/10), and internal septa (3/10). Spatial registration of CT and microscopic sections showed that enhancing tissue was viable tumor in nine of nine. Low attenuation areas were either necrotic (4/9) or of mixed tissue (5/9), including areas of necrosis, fibrosis, and hemorrhage. CONCLUSION The variable tissue composition of HCC accounts for the mosaic CT pattern. In most patients, enhancing nodules indicate viable tumor cells, and low attenuation areas represent necrosis, fibrosis, or hemorrhage.

Performance Evaluation and Quality Assurance of Computed Tomography Scanners, with Illustrations from the EMI, ACTA, and Delta Scanners

Performance evaluation of equipment for computed tomography (CT) involves the integration of: (a) establishing performance criteria; (b) designing and implementing test procedures; and (c) reconciling test results in terms of desired performance. Precision (noise), contrast scale, linearity, accuracy, spatial independence, spatial resolution, artifacts, reproducible performance, and patient exposure are several parameters discussed, as are problems of measurement with regard to non-water bath scanners. Performance and quality control tests for the ACTA, Delta, and EMI scanners are outlined. Guidance for the prospective purchaser of CT equipment is presented as a summary of the ideas discussed.

CT appearance of primary pancreatic lymphoma

Primary lymphoma of the pancreas is a rare neoplasm that may resemble pancreatic carcinoma on CT scans. Two cases with CT findings are presented.

Computed tomography of the abdomen. Early experience with the EMI body scanner.

Normal and pathological anatomy of the abdomen is accurately displayed by computed tomography using the first system capable of completing a scan within a time brief enough to allow the patient to suspend respiration.

Ultrasonography and computed tomography in focal fatty liver: Report of two cases with special emphasis on changing appearances over time

The features of focal fatty infiltration of the liver are described in 2 patients. In 1 patient, hepatic malignancy was initially suspected, and the true nature of the lesion was not appreciated until months later. The nondiagnostic features on ultrasonography and the characteristic features on computed tomography are described. Additional diagnostic information was obtained by guided liver biopsy and from repeat computed tomography months later, when partial or total resolution of the lesions was observed.

Computed tomography of the adrenal gland

A VARIETY of imaging modalities have been employed over the past decade for detection of adrenal tumors. In our institution, these modalities have included excretory urography with tomography, bolus nephrotomography, arteriography, venography, scintigraphy, ultrasonography, and CT. Since 1976, CT scanning of the adrenals has gradually replaced all of the other modalities as the primary method of imaging the adrenal glands. Angiography is employed occasionally to evalute the vascularity of a large mass whose organ of origin remains obscure after CT scanning. Venous sampling is used rarely in selected patients with suspected primary aldosteronism or pheochromocytoma. Ultrasound is used to confirm the fluid nature of an adrenal cyst. lodocholesterol scintigraphy also may be employed in complicated diagnostic problems in some patients with aldosteronism and Cushing syndrome following adrenalectomy. Through January 1980, approximately 15,000 body CT scans were performed in the Department of Diagnostic Radiology with an evolving CT technology. The majority of scans were done with an 18-set scanner. Since December 1979, many of the adrenal scans were performed on a 3-set high resolution CT unit. Approximately 3% of the 15,000 patients referred for CT body scans over a period of 5 yr had suspected adrenal pathology. Of these, slightly more than half had a positive CT scan and showed a spectrum of adrenal pathology (Table I). In 45% of the patients, the adrenal glands were normal on CT, and in a third of

Chemotherapy-related hepatotoxicity causing imaging findings resembling cirrhosis.

In this article, we describe three women in whom changes in the liver resembling cirrhosis occurred during systemic chemotherapy for metastatic breast carcinoma. All three patients were treated with tamoxifen as part of their chemotherapeutic regimen. Abnormalities of biochemical liver tests were associated with the development of a cirrhosis-like appearance of the liver on computed tomography. In two of the patients, hepatic metastases were proved at biopsy. The third patient had no radiologic evidence of metastatic disease. Chemotherapy for metastatic breast carcinoma may cause striking morphologic changes in the liver that resemble cirrhosis. Of importance, these changes should not be mistaken for the development or progression of liver metastases. Alternatively, because of the changes produced by chemotherapeutic agents, detection of metastases on computed tomography alone may be more difficult. Supplementary magnetic resonance imaging may be helpful in selected cases.

MRI of pancreatic islet cell carcinoma.

Objective The purpose of this study is to report the spectrum of MR findings of pancreatic islet cell carcinoma. Materials and Methods The MR scans of 33 patients with islet cell carcinoma were retrospectively reviewed. Magnetic resonance detected the primary tumor in 21 of 27 patients (78%) who had not had prior resection of their primary tumor. Mean tumor diameter was 7.1 cm (range 3.5–13.0 cm). Results In all patients, the primary tumor on T1-weighted images (TR/TE = 250/15) was of signal intensity equal to or lower than that of the adjacent normal pancreas. The primary tumor on T2-weighted images (TR/TE = 2,000/

Computed tomography of liver specimens.

100) was of signal intensity the same as or higher than fat in 18 of 21 patients (86%) and had mixed signal intensity in the other 3 (14%). Hepatic metastases were found in 28 of 33 patients (85%). Liver metastases were categorized as “usual‘’ (variably circumscribed, homogeneous lesions of medium signal intensity on T2-weighted images) in 19 of 28 patients (68%), necrotic in 8 of 28 (29%), hemorrhagic in 3 of 28 (11%), and calcified in 1 of 28 (4%). Extrahepatic metastases were found in 18 of 33 patients (55%). Conclusion We conclude that MRI is an excellent modality for the diagnosis and routine follow-up of patients with islet cell carcinoma.