Francesco Ferrozzi

Mesenchymal tumors of the pancreas: CT findings.

This article reviews the CT imaging features of the most frequent mesenchymal tumors of the pancreas and stresses important distinctive patterns that may help distinguish specific entities. Various neoplasms (lymphangioma, lipoma, teratoma, pancreatoblastoma, schwannoma, neurofibroma, lymphoma, and sarcoma) are reviewed, with key differential points (structure, fatty and water densities, calcification, pattern of contrast enhancement, vascularization, and necrotic or regressive changes) emphasized. In addition, epithelial tumors are considered in the differential diagnosis.

Pancreatic metastases: CT assessment

Abstract We report the CT appearance of pancreatic metastases and describe their features in relation to the originating primary tumor. We also discuss some limitations in their differential diagnosis and report some theories explaining the pathogenesis of their occurrence. A total of 20 cases (9 males and 11 females) of pancreatic metastases were diagnosed at staging or follow-up of oncologic patients. All patients were evaluated with CT before and after contrast medium administration and had subsequent pathologic confirmation. In 1 case metastases were located solely in the pancreas; in 6 there was only another metastatic location, and in the remaining 13 there was diffuse spread throughout the body. Two of our patients exhibited a multinodular metastatic involvement of the pancreas, 11 had a solitary nodule or mass, and the remaining 7 had a diffusely enlarged pancreas, without any signs of focal disease. All but one of the solitary lesions measured more than 4 cm. In 2 cases a metachronous malignancy was detected at follow-up. Primary malignancies were located: 6 in the lungs, 2 on the skin (melanomas), 3 in breasts, 2 in the ovaries, 3 in the colon, 1 in the stomach, 2 in the kidney, and 1 the thyroid. Our findings confirm the existence of three patterns of metastatization to the pancreas: large solitary masses, multinodular lesions, and diffuse enlargement of the pancreas without focal signs at CT. In contrast to other studies, the large solitary lesion was our most frequent encounter, therefore making differential diagnosis vs primary cancer difficult. Metastases tended to repeat the imaging pattern of the primary. Nevertheless, we wrongly diagnosed pancreatitis due to a small nondetected metastasis, pseudo-cystic mass as a mucinous cystadenocarcinoma, conglomerate of peripancreatic lymph nodes, and a solitary pancreatic mass diagnosed as primary pancreatic cancer. Thus, when faced with a solitary pancreatic lesion at follow-up, histologic diagnosis is strongly recommended. In 2 cases changes in aspect and size were related to therapy.

Central nervous system atypical teratoid/rhabdoid tumour of infancy: CT And mr findings

In 1995, as a result of the observation of Rhabdoid elements among the other components of a Teratoid/Rhabdoid tumor (TRT), a new nomenclature was introduced, Atypical Teratoid/Rhabdoid Tumor (ATRT) of infancy and childhood. We report the clinical history and radiological findings in a child affected by central nervous system (CNS) ATRT.

Brain apparent diffusion coefficient evaluation in pediatric patients with neurofibromatosis type 1

Objective: The most frequent intracranial appearance in children with neurofibromatosis type 1 (NF1) is represented by the presence of hyperintense lesions on T2-weighted images, the so-called “unidentified bright objects” (UBOs). Di Paolo demonstrated that these lesions represent foci of myelin vacuolization with increased water content. The aim of this study was to investigate the isotropic apparent diffusion coefficient (ADC) values within the UBOs and normal-appearing brain and at the regressed UBO sites. Methods: Fifteen consecutive children with NF1 underwent magnetic resonance diffusion evaluation of the brain. Fifteen healthy age- and sex-matched children constituted the control group. Apparent diffusion coefficient maps were obtained, and regions of interest were placed bilaterally in 8 different areas. Two cortical areas were evaluated using single-pixel analysis. Apparent diffusion coefficient values within the UBOs were calculated by using irregular regions of interest. Regressed UBO sites were investigated by using circular regions of interest. Apparent diffusion coefficient values within the different areas were compared using a t test. Results: Compared with the controls, NF1 patients showed higher ADC values (P < 0.001) in all locations. In the NF1 group, the mean ADC value in the UBOs was higher than in other locations (P < 0.001). The mean ADC value within the regressed UBO sites was higher than in the normal-appearing locations (P < 0.001). Conclusions: The higher ADC values in children with NF1 suggest an increase in water content of the normal-appearing brain. The UBOs are the areas with the highest water content. The regressed UBOs sites show higher water content than the normal-appearing areas.

Non-Hodgkin lymphomas of the ovaries: MR findings.

PURPOSE The goal of this work was to describe MR findings (morphology, structure, signal intensity) of ovarian non-Hodgkin lymphoma (NHL). METHOD We reviewed the MR images of five female patients aged 13-70 years (mean 46 years) with histologically proven NHL of the ovaries. We evaluated morphological and signal intensity findings of the lesions. MR features were correlated with pathologic parameters. RESULTS All the patients were affected by B-cell NHL; one patient showed a primary involvement of the ovaries; in one patient, ovarian disease was diagnosed 30 months after surgical resection of a primary uterine lymphoma; the remaining three had a systemic lymphoma. In three cases, the ovarian involvement was bilateral. The mean size of the lesions was 7.9 cm. All the lesions showed homogeneous low signal intensity on T1-weighted images and intermediate to high intensity on T2-weighted images. The postgadolinium images showed mild to moderate heterogeneous enhancement. The peripheral enhancement was better demonstrated in fat-suppressed images. CONCLUSION The diagnosis of primary ovarian lymphoma should be considered in the presence of large bilateral solid ovarian masses with homogeneous appearance (low signal on T1 and mildly high on T2) without infiltrative pattern of growth or regressive changes (necrosis, hemorrhage, calcifications) and with little contrast enhancement.

Lipomatous tumors of the stomach: CT findings and differential diagnosis.

This article reviews the computed tomography imaging features of a variety of gastric tumors containing fatty tissue. Lipoma, angiolipoma, liposarcoma, and teratoma are described. Differential diagnosis includes primary and reactive lipomatosis, carcinoma engulfing the perivisceral fat thus mimicking differentiated liposarcoma, and mesenchymal gastric and peritoneal neoplasms.

Primary liver leiomyosarcoma: CT appearance

Abstract. Primary hepatic leiomyosarcomas are exceedingly rare tumors. To the best of our knowledge, only 17 cases have been reported in literature. We report the computed tomographic findings of two cases of primary location in the liver. We also discuss the differential diagnosis of such lesions.

Thin-section ct follow-up of metastatic ovarian carcinoma correlation with levels of CA-125 marker and clinical history

Second-look laparotomy and CA-125 are the gold standard in follow-up of ovarian carcinoma. Since no definite role seems established for cross-sectional imaging in assessment of recurrence we employed thin-section computed tomography (CT), correlated with CA-125 levels and detailed knowledge of the clinical history as a follow-up protocol One hundred seventy-seven patients with ovarian carcinoma were selected because of: (a) pathologically proven remission after first-line chemotherapy, (b) follow-up by means of thin-section CT every 6 months for the fist 3 years and every 10 months subsequently, (c) monitoring CA-125 serum levels every 3 months for the first 3 years and every 6 months subsequently; (d) pathologic confirmation or clinical and laboratory follow-up after 12 months or longer for the CT findings. Fifty percent of the patients showed recurrence of disease. Our protocol yielded 93.2% true positive, dubious findings in 5.6% 1.0% false negatives, 97.7% true negative, and 2.3% false positive. With a tailored technique, CT was particularly sensitive in early diagnosis of peritoneal seeding, even in the absence of ascites or increases in the levels of CA-125. Repeated administration of contrast medium, water enemas, and repeated scanning of suspicious volumes with differing scanning parameters were the factors managed by the radiologist. We conclude that thin-section CT, correlated with CA-125 levels and careful review of the clinical history could represent a valid alternative to repeated explorative laparotomies in the follow-up of ovarian carcinomas.

Gastric liposarcoma: CT appearance

Two cases of liposarcoma of the stomach are described. At computed tomography (CT) the neoplasms showed features of an aggressive malignant tumor, with no fatty values within. We discuss the differential diagnosis of such lesions and conclude that, although rare, liposarcoma should be considered as a possible diagnosis when a large exophytic gastric mass is detected at CT.

Pseudotumoral bilateral involvement of the breast in Erdheim-Chester disease: CT appearance.

We report a case of pseudotumoral involvement of the breast in Erdheim-Chester disease. CT shows an enlargement of both breasts with inhomogeneous structure, microcalcifications, and foci of fatty density.