Javier-A. Novales-Diaz

FDG PET/CT imaging in primary osseous and soft tissue sarcomas: a retrospective review of 212 cases

PurposeThe aims of this study are to evaluate the sensitivity of FDG PET/CT for detection of soft tissue and osseous sarcomas on the basis of FDG avidity.MethodsWe retrospectively evaluated 212 consecutive patients with known soft tissue or osseous sarcoma who had undergone a FDG PET/CT study for the initial staging or assessment of recurrence of disease. The maximum standardized uptake value (SUVmax) of each primary and/or most intense metastatic lesion was measured and compared with the histological data provided in the final pathological reports. An SUVmax of 2.5 or greater was considered positive for our analysis.ResultsSufficient histopathological data were available for 160 soft tissue sarcomas and 52 osseous sarcomas. FDG PET/CT detected 93.9% of all sarcomas with a sensitivity of 93.7% for soft tissue sarcomas and 94.6% for osseous sarcomas. The sensitivities of the most common sarcoma histologies were 100% for leiomyosarcomas, 94.7% for osteosarcomas, 100% for Ewing’s sarcomas, 88.9% for liposarcomas, 80.0% for synovial sarcomas, 100% for gastrointestinal stromal tumors, 87.5% for malignant peripheral nerve sheath tumors, 100% for fibroblastic and myoblastic sarcomas, and 100% for malignant fibrohistiocytic tumors. The receiver-operating characteristic curve revealed an area under the curve of 94% for the discrimination of low-grade and high-grade sarcomas imaged for initial staging by FDG PET/CT.ConclusionThe combined metabolic and morphological information of FDG PET/CT imaging allows high sensitivity for the detection of various sarcomas and accurate discrimination between newly diagnosed low-grade and high-grade sarcomas.

Tc-99m red blood cell venography in deep venous thrombosis of the lower limb. An overview

Tc-99m red blood cell venography is a simple and sensitive technique for the diagnosis of deep vein thrombosis of the lower limb. The static high count blood pool images of the deep venous system of the leg are readily interpretable and show good correlation with contrast venography. The advantages and limitations of this technique in the clinical setting are discussed in detail in this review.

Cardiac T-cell lymphoma imaged with F-18 FDG PET-CT and correlative imaging.

Primary cardiac tumors are rare, and of these, primary cardiac lymphomas account for less than 1%. Most are B-cell non-Hodgkin lym- phomas, and the right atrium and right ventricle are the most frequently involved sites. The clinical presentation varies, but commonly involves pericardial effusions, AV block, valvular dysfunction, or heart failure. We present a 72-year-old man who was referred for an F-18 FDG PET-CT scan to evaluate a cardiac mass. An intensely hypermetabolic mass was observed replacing most of the right ventricle, which was confirmed with a contrast- enhanced CT as well as magnetic resonance imaging. Endomyocardial biopsy revealed a low-grade T-cell lymphoma. This is a rare report of a cardiac T-cell lymphoma imaged with F-18 FDG PET-CT.

Primary thyroid osteosarcoma: staging and evaluation of response to therapy with F-18 FDG PET-CT.

Extraosseous osteosarcomas account for less than 5% of all osteosarcomas. Primary osteosarcoma of the thyroid is a very rare tumor, with only 28 cases described in the published data. This is a case of a 40-year-old woman, 3 months postpartum, who presented with a rapidly growing mass in the neck, causing airway obstruction. An F-18 FDG PET-CT showed a large intensely FDG-avid mass in the thyroid gland, which was histopathologically confirmed to be a primary thyroid osteosarcoma. The patient was treated with tracheostomy, radiation therapy, and 2 cycles of chemotherapy. A posttherapy F-18 FDG PET-CT scan showed that the thyroid osteosarcoma was responding to therapy; however, the patient had developed new lung metastases.

Sarcomatoid carcinoma (carcinosarcoma) of the lung mimics malignant pleural mesothelioma on 18F-FDG PET/CT: a report of 2 cases.

Sarcomatoid carcinomas of the lung account for less than 0.4% of all lung tumors, and they are a heterogeneous group of non–small-cell lung carcinomas containing a sarcoma or sarcoma-like component. They have a poor prognosis, with an overall 5-year survival of 25% compared with 45% for other types of non–small-cell lung carcinomas. The literature on the use of F-FDG PET/CT to stage these tumors is very limited, and their PET/CT imaging characteristics have not been previously described. We report on 2 cases of sarcomatoid carcinoma that resembled malignant pleural mesothelioma on F-FDG PET/CT and were correctly staged.

Extramedullary Gastric Relapse of Acute Lymphoblastic Leukemia Following Allogeneic Stem Cell Transplant: Staging With F-18 Fdg Pet/ct

A 26-year-old man with a prior history of acute leukemia that was treated with a stem cell transplant (SCT) was referred for an F-18 FDG PET/CT to assess suspicious new gastric mucosal lesions. The lesions were FDG-avid and were histologically proven to be acute lymphoblastic leukemia (ALL). Extramedullary relapse of ALL after SCT is very rare, with only 60 cases reported in the literature, and the role of F-18 FDG PET/CT in monitoring for ALL relapse following SCT has not been previously investigated. This rare case report highlights the use of F-18 FDG PET/CT in staging gastric relapse of ALL following SCT.

Spectrum of gastric malignancy on 18F-FDG PET/CT: a pictorial essay

A wide variety of malignant gastric diseases can be detected, staged, and followed on (18)F-FDG PET/CT. Although the PET/CT findings are often nonspecific and some can be seen in certain benign gastric diseases, the aim of this atlas was to demonstrate that the wide histological spectrum of gastric tumors that can be evaluated, staged, and followed with PET/CT is much broader than current medical literature would suggest. PET/CT readers and oncologists should be aware of the utility of PET/CT in these tumors and the imaging characteristics and patterns of (18)F-FDG uptake that can be demonstrated in these cases.

Radiocolloid liver imaging in hepatic steatosis.

In a review of 60 patients with fatty infiltration of the liver documented by Xe-133 imaging, 43% had normal radiocolloid liver images, and 57% had abnormal images with various combinations of hepatomegaly, mottling, splenomegaly, and splenic shift of radioactivity. None, however, showed focal defects. Fatty infiltrates do not simulate mass lesions on the radiocolloid study of the liver, and an area of photon deficiency in the presence of hepatic steatosis points to an additional pathologic process. The interpretation of the radiocolloid liver image is unhindered by fatty infiltration when searching for discrete space-occupying lesions.

Progressive transformation of germinal centers in a pediatric patient: initial evaluation and follow-up with serial F-18 FDG PET/CT imaging.

Progressive transformation of germinal centers (PTGC) is a benign reactive adenopathy that leads to abnormal nodal enlargement. Although not believed to be premalignant, recent genetic studies have found evidence linking PTGC to Hodgkin lymphoma. In this case of a 14-year-old girl referred for an F-18 FDG PET/CT, extensive FDG-avid lymphadenopathy that was suspicious for lymphoma, was confirmed to be PTGC on biopsy. A follow-up PET/CT showed significant resolution of FDG-avid disease. As a new understanding of a possible link between PTGC and Hodgkin lymphoma emerges, serial PET/CT imaging may play a prominent role in the staging and follow-up of PTGC.

Incidental papillary thyroid carcinoma in a patient presenting with Graves' hyperthyroidism and concomitant obstructive sequestered intrathoracic multinodular goiter.

A previously healthy 27-year-old woman presented with a thyroid goiter, symptoms of thyrotoxicosis, and mild respiratory obstruction. The serum thyroid stimulating hormone (TSH) was suppressed, serum T4 was elevated, and 24-hour radioiodine uptake was elevated at 59%. Thyroid scintigraphy showed intense uptake in an enlarged gland, with a cold nodule on the right, and a large isolated mass in the mediastinum, with very mild uptake. Total thyroidectomy and excision of the mediastinal mass revealed multiple pathologies: Graves disease in the thyroid gland with an incidental papillary thyroid carcinoma, and a benign sequestered intrathoracic multinodular goiter. Thyroid carcinoma can develop in a gland affected by Graves disease, however, the presence of concomitant sequestered intrathoracic thyroid tissue unaffected by Graves disease is highly unusual and has not been previously described. We present the scintigraphic findings, and several theories that could help explain these findings.