technetium-tc-99m-sulfur-colloid and Pancreatic-Neoplasms

The interaction between the various noninvasive and invasive imaging modalities used to evaluate the liver, biliary tract, and pancreas is demonstrated in this article. By understanding this interaction and correlating noninvasive studies, the clinician will avoid diagnostic redundancy and the need for invasive testing may be reduced.

Topics: Adenocarcinoma; Biliary Tract Diseases; Biopsy, Needle; Cholangiography; Cholecystectomy; Cholelithiasis; Cholestasis; Diagnosis, Differential; Hepatectomy; Humans; Liver; Liver Diseases; Liver Neoplasms; Pancreatic Diseases; Pancreatic Neoplasms; Pancreatitis; Radionuclide Imaging; Spleen; Technetium Tc 99m Sulfur Colloid; Tomography, X-Ray Computed; Ultrasonography

Although FDG PET is increasingly used for the staging of many types of sarcoma, little has been written regarding the FDG PET imaging characteristics of solitary fibrous tumor. We report a patient undergoing FDG PET/CT surveillance for squamous cell carcinoma of the tongue who was incidentally found to have two soft tissue masses in the retroperitoneum and pancreatic tail. Due to their low degree of FDG avidity, they were followed conservatively for approximately one year as they gradually increased in size. Technetium-99m sulfur colloid SPECT helped confirm that the pancreatic tail mass was not a splenule, after which both lesions were surgically resected and found to be extrathoracic solitary fibrous tumors without malignant features. These findings suggest that, as with other low-grade sarcomas, benign extrathoracic solitary fibrous tumors exhibit relatively little glycolytic metabolism in vivo.

Topics: Carcinoma, Squamous Cell; Fluorodeoxyglucose F18; Humans; Incidental Findings; Male; Middle Aged; Multimodal Imaging; Neoplasms, Multiple Primary; Pancreatic Neoplasms; Positron-Emission Tomography; Radiopharmaceuticals; Retroperitoneal Neoplasms; Solitary Fibrous Tumors; Technetium Tc 99m Sulfur Colloid; Tomography, X-Ray Computed; Tongue Neoplasms

A 99mTc-sulfur colloid (99mTc-SC) scintigraphic study of a patient with pancreatic carcinoma invading the splenic hilum demonstrated a discrete focal defect of the spleen, while computed tomography (CT) showed a normal spleen. The patient underwent splenectomy and no pathology was found in the spleen. The tumor invasion into the splenic hilum may have caused the defect shown in the 99mTC-SC study, reflecting splenic reticuloendothelial (RE) cell dysfunction, while CT might well represent anatomic structures only. This discrepant finding between functional (99mTc-SC) and anatomic (CT) imaging modalities may be explained by the fact that the impairment of the phagocytic function of the spleen apparently was not severe enough to cause structural changes detected by CT or gross and microscope examination.

Topics: Humans; Male; Middle Aged; Pancreatic Neoplasms; Radionuclide Imaging; Spleen; Technetium Tc 99m Sulfur Colloid; Tomography, X-Ray Computed

Relative spleen/liver activity ratio was determined from posterior projection images using a photodensitometric method. Ratios from scans of 22 patients with proven pancreatic carcinoma (12 from rectilinear scans and 10 from scintillation camera images) were determined and compared to studies from patients documented as normal and to randomly selected liver/spleen imaging studies which had been previously interpreted as normal. The mean ratio from the pancreatic carcinoma group was significantly lower than the means of the respective normal groups (p[t] less than .0001 for rectilinear scans and p[t] less than .001 for scintigrams). There was no significant difference between the means of the proven normal and randomly selected normal groups or between the two pancreatic carcinoma groups. Splenic vascular alteration is discussed as a possible reason for decreased splenic distribution of Tc-99m-sulfur colloid in this patient group.

Topics: Adolescent; Adult; Aged; Child; Humans; Liver; Middle Aged; Pancreatic Neoplasms; Radionuclide Imaging; Spleen; Sulfur; Technetium; Technetium Tc 99m Sulfur Colloid