Giant cell tumor is the sixth most frequent primary bone neoplasm, affecting long bone metaphysis, most frequently in young adults. On radiological images, this tumor appears as a lytic, well-defined, eccentric lesion. The authors report a case of benign giant cell tumor in a patient who presented with lung metastases five years after undergoing resection of the primary tumor.

Keywords: Giant cell tumor, Benign, Metastasis

OBJECTIVE: To evaluate the frequency of hypervascularization by visualizing vascular structures inside or around bone metastases from renal cell carcinoma. MATERIALS AND METHODS: Magnetic resonance imaging studies of 13 untreated patients with diagnosis of renal cell carcinoma and 15 metastatic bone lesions were retrospectively evaluated. RESULTS: Signs of hypervascularization were found in 12 of the 15 bone lesions (80%), 6 of them localized in the lumbar spine, 3 in the hip, 3 in the thoracic spine, 1 in the ulna and 1 in the tibia. CONCLUSION: The high frequency of hypervascularization of bone metastases from renal cell carcinoma found in the present study may suggest that the renal etiology is a useful parameter in the evaluation of a usual clinical presentation of a single bone lesion with unknown primary neoplasm.

Keywords: Bone metastases, Renal cell carcinoma, Magnetic resonance imaging, Hypervascularization

OBJECTIVE: To present computed tomography findings observed in four patients submitted to radical nephrectomy for renal cell carcinoma who developed pancreatic metastases afterwards. MATERIALS AND METHODS: The four patients underwent radical nephrectomy for stage T1 (n=2) and stage T3a (n=2) renal cell carcinoma. The mean interval between nephrectomy and detection of pancreatic metastases was eight years. Two asymptomatic patients presented with solitary pancreatic metastases (confined to the pancreas). Two symptomatic patients presented with single and multiple pancreatic metastases, both with tumor recurrence in the contralateral kidney. RESULTS: Computed tomography studies demonstrated pancreatic metastases as solitary (n=2), single (n=1) or multiple (n=1) hypervascular lesions. Partial pancreatectomy was performed in two patients with solitary pancreatic metastases and both are free of disease at four and two years after surgery. CONCLUSION: Pancreatic metastases from renal cell carcinoma are rare and can occur many years after the primary tumor presentation. Multiple pancreatic metastases and pancreatic metastases associated with tumor recurrence in the contralateral kidney are uncommon. Usually, on computed tomography images pancreatic metastases are visualized as solitary hypervascular lesions, simulating islet-cell tumors. Surgical management should be considered for patients with solitary pancreatic lesions.

Keywords: Pancreatic metastases, Renal cell carcinoma, Computed tomography

OBJECTIVE: The critical analysis of the methodology for evaluating the x-ray beam half-value layer was based on technical standards for radiological protection and quality control in medical and dental diagnoses. MATERIALS AND METHODS: Exposure parameters, experimental set-up, scattering materials, instrumentation, size of radiation field and methodology of data analysis have been taken into consideration for measurements of half-value layer. RESULTS: The half-value layer, in good geometry, measured 2.44 ± 0.02 mmAl. A maximum deviation of 4.1% was found under other geometry conditions. A 98.8% deviation was observed with a different ionization chamber, and scattering material, and 29.5% with another type of detector. CONCLUSION: Results showed that no relevant variation is observed in the half-value layer for different radiation field sizes. On the other hand, the influence of the radiation scattering on the half-value layer overestimation was clearly observed, as well as the half-value layer reduction in the presence of lead used as scattering material. The practical methodology adopted for half-value layer evaluation has shown to be quite reliable, besides evidencing remarkable discrepancies resulting from the adoption of inappropriate methodologies, emphasizing the necessity of establishing a standard procedure for measuring the half-value layer.

Keywords: Half value layer, HVL, Quality control, Diagnostic radiology

OBJECTIVE: To verify if the use of InGaAIP laser with 685 nm wave length can reduce the xerostomy incidence, the oral mucositis severity and the pain related to mucositis in patients with head and neck cancer submitted to radiotherapy. MATERIALS AND METHODS: Sixty patients presenting head and neck carcinoma were submitted to radiotherapy with daily doses of 1.8 to 2.0 Gy and a final dose of 45 to 72 Gy. The salivary volume was evaluated in the first and fifteenth days, at the end of the treatment and after 15 and 30 days. The oral mucositis was evaluated on a weekly basis. Twenty-nine patients were submitted to radiotherapy without laser and 31 were submitted to radiotherapy and laser with daily doses of 2 joules/cm² in predetermined areas of the oral mucosa and the parotid and submandibular glands. RESULTS: In the group submitted to radiotherapy and laser the incidence of mucositis (p < 0.001) and pain (p < 0.016) was significantly lower and the salivary volume (p < 0.001) was kept higher during and after the treatment. CONCLUSION: The group of patients submitted to radiotherapy and laser had lower incidence of xerostomy, oral mucositis and pain when compared to the group treated with radioteraphy without laser, producing statistically significant results.

Keywords: Low level laser, Xerostomy, Mucositis, Radiotherapy, Chemotherapy

The authors review the main findings of primary adrenal lymphoma on abdominal and brain computed tomography (CT) scans and brain magnetic resonance imaging (MRI), and report a rare case of a 72-year-old male patient with deterioration in mental status progressing from recent memory loss to disorientation and ultimately dementia in a period of two months. The patient was investigated using imaging methods including brain (without intravenous administration of iodinated contrast media), chest and abdomen (pre and post intravenous administration of iodinated contrast media) CT scans and brain MRI (pre and post intravenous administration of gadolinium). Brain CT scan showed slightly hyperdense nodules adjacent to the lateral ventricles. No gross abnormalities were seen on the chest CT scan. CT of the abdomen showed solid nodules on both adrenals. Brain MRI showed diffuse nodular enhancement of the ependyma of the fourth ventricle, third ventricle, frontal and temporal horns, atria and body of the lateral ventricles. Definitive diagnosis was made by immunohistochemical study of the biopsed adrenal. After a comprehensive review of the literature the authors concluded that CT and MRI are essential methods for the detection and accurate evaluation of primary adrenal lymphomas, particularly when there is involvement of the central nervous system. MRI is more sensitive in the detection of extracerebral lesions in the epidural and subdural spaces, especially after intravenous administration of gadolinium.

Keywords: Adrenal lymphoma, Central nervous system metastases, Computed tomography, Magnetic resonance imaging

Laser-induced thermoablation has been used as a reliable method for producing coagulation necrosis in hepatic tumors in patients who are not suitable for surgical treatment. The procedure can be performed percutaneously, using image-guiding methods, by open laparotomy or laparoscopy. We review the current literature and discuss the principles, indications, complications and clinical results as well as the potential limitations and contraindications of this novel technique.

Keywords: Laser, Thermoablation, Liver, Liver tumors, Metastases

Recent advances in ultrasound have optimized the detection of liver tumors and helped to improve the prognosis of patients with this condition as newly developed and improved therapeutic modalities have been established. The authors review important Doppler findings which may help in the identification and characterization of some hepatic tumors through the evaluation of color Doppler, pulsed Doppler and power Doppler features. New imaging methods such as the use of harmonics imaging are also reviewed.

Keywords: Liver, Liver tumors, Doppler

Vascular tumors encompass a spectrum of lesions, which may vary from benign hemangiomas to malignant angiosarcomas. Hemangioendotheliomas can be considered intermediary between these two types of lesions. We report a case of hepatic hemangioendothelioma in a newborn female and review the most important aspects of this disease.

Keywords: Hemangioendotheliomas, Hepatic tumors, Vascular tumors, Computed tomography

The authors studied seven patients with gingival carcinoma attended at the Head and Neck Surgery and Otorrhinolaryngology Service and the Diagnostic Imaging Service of "Complexo Hospitalar Heliópolis", São Paulo, SP, Brazil, between 1985 and 1996. Squamous cell type carcinomas were identified in all cases. All patients were male (100%) aged 48-72 years. Computed tomography was performed in six patients (85.6%). Four patients (57.1%) had not received any treatment before imaging examination whereas three patients (42.8%) had already been submitted to surgery or radiotherapy. The authors analyzed the primary site of the tumor and its extension to the mandible (5/7 cases; 71.4%), the floor of the mouth (3/7 cases; 42.8%), the floor of the maxillary sinus (1/7 cases; 14.2%) and the retromolar trigonum (1/7 cases; 14.2%). Metastatic lymph nodes were observed in five patients (71.4%). Diagnosis was confirmed by biopsy and histopathological examination in all cases. Comparison with surgical findings was possible in five cases (71.4%).

Keywords: Gingiva, Malignant tumors, Gingiva

Choroid plexus mass lesions encompass a broad and heterogeneous group of diseases and their simulators. Tumors, infections, congenital anomalies, hemorrhage, cysts and degenerative diseases are some examples of mass lesions affecting the choroid plexus. In this article we review the current literature, describing the imaging findings and illustrating choroid plexus mass lesions with some cases diagnosed at our facility. Despite the inexistence of pathognomonic signs, a careful and systematic evaluation of the imaging characteristics may suggest many etiologies.

Keywords: Choroid plexus, Tumors, Mass lesions

Gastric cancer frequently presents intraperitoneal spread. Distant metastases are rare. The authors describe a case of a 47-year-old white man, long-term cigarette smoker, who had a right upper lobe mass seen on plain films and computed tomography of the chest. A gastric adenocarcinoma was concomitantly diagnosed by endoscopic examination. A bronchoscopy guided biopsy showed that the lung mass was in fact a metastasis from gastric adenocarcinoma. In this article, the imaging findings of gastric cancer and the patterns of dissemination to other organs are reviewed.

Keywords: Gastric cancer, Lung metastasis, Bone metastasis, Computed tomography

The authors report a case where a quantitative assessment of the apparent diffusion coefficient (ADC) of liver metastasis in a patient undergoing chemotherapy has shown to be an effective early marker for predicting therapeutic response, anticipating changes in tumor size. A lesion with lower initial ADC value and early increase in such value in the course of the treatment tends to present a better therapeutic response.

Keywords: Magnetic resonance imaging; Diffusion; Liver metastases; Breast cancer; Chemotherapy; Therapy monitoring.

The authors describe the case of a 33-year-old patient with history of seizures alone without any previous symptom, being diagnosed with brain metastases from primary papillary adenocarcinoma of the lung. Emphasis is given to the diagnostic investigation for brain metastasis and prognostic evaluation of papillary adenocarcinoma of the lung, and a brief literature review on such diseases is performed.

Keywords: Neoplastic metastasis; Papillary adenocarcinoma; Immunohistochemistry.

Neuroendocrine neoplasms (NENs) are a heterogeneous group of tumors with distinct morphological and biological manifestations, the liver being the main organ affected by its metastases. However, primary hepatic involvement is quite rare. Hepatic NENs can have a variety of radiological presentation forms and can therefore mimic other lesions, making their diagnosis challenging. Nonetheless, certain imaging aspects allow NENs to be included among the main differential diagnoses of hepatic lesions and can guide the search for an extrahepatic primary site when the probable diagnosis is metastases.

Keywords: Carcinoma, neuroendocrine; Neuroendocrine tumors; Neoplasm metastasis; Liver.