[Cellular dynamics of pathogenesis induced by bovine leukemia virus]

Bovine leukemia virus (BLV) is the etiological agent of a lymphoproliferative disease in cattle. This retrovirus can also be experimentally transmitted to sheep, in which the pathology is more rapid and more frequent. This review summarizes the current knowledge on the BLV virus and more particularly on its role in lymphocyte homeostasis and induction of pathogenesis. This system has been informative for understanding pathogenesis induced by human T-lymphotropic virus type I (HTLV-1).

Comparison of metabolic activity in mantle cell lymphoma at biospy site and other tumor sites using 18F-FDG PET

18529

Background: Mantle cell lymphoma (MCL) is a mature B-cell non-Hodgkin’s lymphoma (NHL) with a variable clinical course ranging from indolent to aggressive. Treatment for MCL is complicated by this variability, as systemic chemotherapy for NHL is directed by the aggressiveness of the lymphoma. Previous attempts have been made to correlate clinical outcome in MCL with histologic features. More recently, measurement of metabolic activity using 18F-fluorodeoxyglucose-positron emission tomography (FDG-PET) was found to be highly correlative with the aggressiveness of NHL. Given the clinical heterogeneity of MCL, the search for the true metabolic status in MCL is important in prognostication and management. We propose to study the metabolic activity in MCL by comparing the maximum SUV at the site of biopsy with the highest SUV in other MCL areas of the body. Methods: 12 patients with newly diagnosed MCL and having staging by FDG-PET were identified. PET(CT) body scans were obtained in the usual fashion. The SUVs, defined as tumor activity divided by dose injected per lean body mass, from the PET and PET-CT cameras were cross validated to produce the same value in a given phantom and patient. Maximum biopsy SUV was measured by searching the maximum value within a volume of interest over the known biopsy site, and highest body SUV was similarly searched in known tumor sites in other body areas. Results: One patient was excluded because the tumor at the biopsy site had been completely resected. The remaining 11 patients (M:F=8:3, age=63±8 yrs) were analyzed. The SUV at biopsy sites ranged from 2.1 to 9.8 (mean=5.2±2.3). The SUV in other tumor sites ranged from 4.8 to 18.6 (mean=8.9±4.1), which was significantly higher when compared to the respective biopsy site (p=0.0036). Conclusions: As the SUV of MCL at the biopsy site may not represent the highest SUV, it is important to search other tumor sites in the body for the highest SUV to help in grading, managing, and subsequent monitoring of MCL. Perhaps FDG-PET can direct biopsies to tumor sites with the highest SUV and subsequently provide useful histologic detail for predicting clinical course. Future study is needed to correlate the maximal SUV of MCL with histology and clinical course.

No significant financial relationships to disclose.

Patterns of abnormal FDG uptake by various histological types of non-small cell lung cancer at initial staging by PET

The aim of this study was to identify useful patterns of abnormal fluorine-18 fluorodeoxyglucose (FDG) uptake by different types of non-small cell (NSC) lung cancer and to assess their clinical implications. One hundred and three sequential patients with newly diagnosed, pathology-proven NSC lung cancer were included. FDG positron emission tomography (PET) images were acquired using a dedicated PET scanner. There were 35 squamous cell carcinomas (SQC), 17 large cell cancers (LGC), 38 adenocarcinomas (ADC), 1 bronchioloalveolar carcinoma (BAC) and 12 non-classified NSC cancers. PET images were categorized into detectable patterns of necrotic center in the primary tumor, satellite lesions (T4), hilar lymph nodes (N1), and N2, N3, and M1 lesions by visual interpretation of PET images for SQC, LGC, and ADC (n=90; BAC and non-classified NSC cancers were excluded). The PET lesions were correlated with surgical pathology and with CT findings in inoperable cases. Necrosis was more commonly present in the primary tumors of LGC (53%) and SQC (43%) than in those of ADC (26%) (P<0.0001 and <0.01, respectively). The frequencies of nodal uptake in ADC, SQC and LGC were similar (71%, 60%, and 59%, respectively). However, M1 lesions were present significantly more often in LGC (41%) and ADC (34%) than in SQC (3%) (both P<0.0001). Significantly more surgically inoperable cases were found by PET (T4, N3, M1) in ADC (50%) and LGC (41%) than in SQC (26%) (P<0.001 and <0.02, respectively). Our results suggest a wide variation of PET findings for different types of NSC lung cancer. Identification of these patterns is useful in clinical PET interpretation, in that knowledge of the most probable association between the PET patterns and the histological types will facilitate initial staging and planning of management.

A clear cell variant of follicular carcinoma presenting as an autonomously functioning thyroid nodule

We report a case of an autonomously functioning thyroid nodule (AFTN) that proved to be almost exclusively a clear cell variant of follicular carcinoma. AFTNs are generally felt to be benign lesions with exceptions forming the basis of case reports. Likewise, clear cell tumors of the thyroid are rare. To our knowledge, this combination of two unusual thyroid conditions has not been previously reported. The initial scans of this patient were so characteristic for a degenerating AFTN that attention was first directed toward a very large contralateral lobe. While it is debatable whether all AFTNs should be biopsied, on the basis of this and other cases, it is recommended that AFTNs that contain a central photopenic area on scan be biopsied to be sure that cystic degeneration, a commonly seen phenomenon in larger AFTNs, is indeed present rather than a malignancy.

The sensitivity of renal scintigraphy and sonography in detecting nonobstructive acute pyelonephritis

Recently it has been demonstrated that any child with proved acute pyelonephritis may be at risk for parenchymal scarring, whether or not reflux is present. Since cortical renal scintigraphy has been shown to detect accurately renal inflammation, we compared cortical scintigraphy with renal sonography in 46 children with documented acute pyelonephritis to determine which modality is best to detect patients at risk for renal injury. Cortical scintigraphy was abnormal in 36 children (78%) and renal ultrasonography was abnormal in 5 (11%). Reflux was demonstrated in only 20 cases (43%). We conclude that cortical scintigraphy is the preferred imaging technique for diagnosing renal inflammation, and it should be used routinely in every child with suspected acute pyelonephritis. A new imaging protocol is proposed.

Morphine-augmented cholescintigraphy: its efficacy in detecting acute cholecystitis

Cholescintigrams were performed in 158 patients suspected of having acute cholecystitis after administration of 185 Mbq (5 mCi) of 99mTc-mebrofenin or disofenin. Morphine sulfate, 0.04 mg/kg was given intravenously if there was nonvisualization of the gallbladder at 40-60 min provided that radiotracer was seen within the small bowel. Acute cholecystitis was deemed present if there was nonvisualization of the gallbladder 30 min post-morphine administration; no cystic duct obstruction was present if the gallbladder was demonstrated pre- or post-morphine administration. A final diagnosis was estimated in 51 postoperative patients histologically, the remainder having their final diagnosis gleaned from their medical records. The sensitivity, specificity, positive and negative predictive value of morphine-augmented cholescintigraphy in detecting acute cholecystitis was 94.6, 99.1, 97.2, and 98.3%, respectively. These findings indicate that morphine-augmented cholescintigraphy detects acute cholecystitis with as high a degree of accuracy as conventional hepatobiliary scintigraphy, yet requires only 1.5 hr to establish the diagnosis.