[Bone scintigraphy in two cases of primary vertebral osteosarcoma in adults]. / Gammagrafía ósea en dos casos de osteosarcoma vertebral primario en edad adulta.

The primary vertebral osteosarcoma in adults is a rare tumor which represents less than 2% of all osteosarcomas. We present the cases of two men (40 and 33 years old) who began with pain and neurological compression symptoms. The imaging methods used to study the tumors were X-rays, CT, MRI and bone scintigraphy with 99mTc-HMDP. After the pathological diagnosis, the tumors were removed surgically and the treatment was completed with chemotherapy and radiotherapy. In this report the authors review the published cases of vertebral osteosarcoma, its epidemiology, clinical presentation and characteristics in the different imaging techniques.

[Soft tissue malignant fibrous histiocytoma. Visualization in bone scintigraphy]. / Histiocitoma fibroso maligno de partes blandas. Visualización en gammagrafía ósea.

Malignant fibrous histiocytoma (MFH) is the most common soft tissue malignant tumour in late adult life. MFH has been mentioned to have avid uptake of 67Ga citrate, and only 38% is uptake of 99mTc-MDP, although few cases of MFH have been reported. We present the case of a 73 years old male patient with MFH. In the blood pool phase of the bone scintigraphy, MFH was presented as an intense hyperactive lesion. In the late phase the tumor is one of the few MFH described to have avid uptake for 99mTc-MDP. In this work we also review some cases of MFH described and the different techniques used in the diagnosis and follow-up of these tumours.

[Association of thyroid hemiagenesis and Graves disease]. / Asociación de hemiagenesia tiroidea y enfermedad de Graves.

Thyroid hemiagenesis is a very infrequent abnormality. We present a case of Graves disease associated to a congenital hemiagenesis of the thyroid gland. The thyroid scintigraphy, ultrasonography and laboratory analysis (that showed the existence of thyroid hyperfunction and the present of thyroid stimulating antibodies) were decisive in the diagnosis.

[Hepatobiliary scintigraphy in a case of acute cholecystitis in childhood]. / Gammagrafía hepatobiliar en un caso de colecistitis aguda en la infancia.

Acute cholecystitis is an uncommon disease in childhood. Few cases in patients under 10 years of age have been found in literature. An eight-year old male patient with no history of interest who had acute acalculous cholecystitis was reported. Ultrasonographic and isotopic studies led to the diagnosis and control of the patient's evolution.

[Simple thyroid cyst]. / Quiste simple de tiroides.

Simple or true thyroid cysts are very rare. We only have found one case in which colorless and acellular transparent fluid has been found by means of the fine needle aspiration puncture (FNAP). We report the case of a 33 year old female who first presented with a rapidly growing thyroid nodule. The thyroid scintigraphy revealed the existence of a cold nodule and the ultrasonography showed a lesion having a cystic appearance. The FNAP was performed and was both diagnostic and therapeutic in this case.

[Radioimmunometric assay of neuron specific enolase in aqueous humor and serum in patients with retinoblastoma]. / Determinación radioinmunométrica de la enolasa neuronal específica en humor acuoso y suero, en pacientes con retinoblastoma.

INTRODUCTION: Retinoblastomas (RB) are the most common malignant intraocular tumors in childhood. The neuron specific enolase (NSE) is used as a tumor marker in different malignant diseases (mainly in neuroblastomas and lung carcinoma of small cells). In this work we report our experience using NSE and the role we consider that it plays in the determination of this enzyme in RB cases. MATERIALS AND METHODS: NSE determinations in aqueous humor (AH) and serum were carried out in 17 RB by means of a radioimmunometric assay and were compared with those values obtained in a control group composed of 8 subjects in whom the RB diagnosis as well as other diseases that could alter its determination had been ruled out. The possible correlation between NSE levels and different tumor stages (Reese-Elsworth and histological-clinical), as well as the tumor type (exophytic and mixed) were also studied. RESULTS: NSE levels were increased in AH and serum in 88% of RB patients and were normal in all the subjects in the control group (when a sample which was considered to be non-valid due to the presence of red cells in AH was excluded). No correlation between NSE levels in AH and serum and the different tumor stages was found. Nevertheless, the RB group of mixed tumor type showed a significantly higher mean in AH (p<0.01) than the RB exophytic group. CONCLUSION: NSE determination in AH is of value in the differential diagnosis in patients in whom RB is suspected but difficult to diagnose as well as in the diagnosis of relapses. Serum determinations are mainly useful in the follow-up and in the early diagnosis of possible metastases.

[Thyroid scintigraphy and body scanning with 67 Ga in a case of primary thyroid lymphoma]. / Gammagrafía tiroidea y rastreo corporal con 67Ga en un caso de linfoma tiroideo primario.

The case of a 60-year old woman first presented a rapidly growing left cervical mass is presented. The fine needle aspiration-puncture (FNAP) lead to a diagnosis of thyroiditis. Due to the persistence of the symptoms, the FNAP was repeated again but was not conclusive, so that a surgical biopsy was performed. The pathological diagnosis was diffuse large cell primary thyroid lymphoma (PTL). The PTL is a rare entity that accounts for less than 1% of all the Non-Hodgkin's lymphomas. The thyroid scintigraphy showed the existence of a cold nodule in the left thyroid lobule and the 67Ga scan revealed a large abnormal lesion in the mediastinum that extended to the right latero-cervical region. After two chemotherapy courses, the 67Ga scan was normal.

[Value of 123I-MIBG scanning, neuron-specific enolase and serum ferritin in the diagnosis and follow-up of patients with neuroblastoma]. / Valor del rastreo con 123I-MIBG, enolasa neuronal específica y ferritina sérica en el diagnóstico y seguimiento de pacientes con neuroblastoma.

INTRODUCTION: The neuroblastoma (NB) is one of the most common pediatric malignant neoplasms. The most commonly used tumor markers in the diagnosis and follow-up of this tumor are the serum neuron-specific enolase (NSE), ferritin and lactic dehydrogenase and urinary vanillymandelic and homovanillic acid. The common imaging modalities are CT, MRI and 123I or 131I-meta-iodobenzylguanidine scintigraphy. AIM: The aim of this study is to assess the value of 123I-meta-iodobenzylguanidine (MIBG) scintigraphy and serum determinations of NSE and ferritin in the diagnosis and evolution of NB patients. MATERIAL AND METHODS: 20 patients (8 female, 12 male) whose ages ranged from 2 months to 9 years with a mean age of 2.64 years diagnosed of NB. 47 123I-MIBG scans, 47 NSE determinations and 47 ferritin ones were selected. RESULTS: At the time of diagnosis, 100% of the 123I-MIBG scans were positive. 65% of NSE determinations presented clearly pathological levels and 15% were very near to the cut-off point. Only 45% of the ferritin levels were increased. The differences between the lesions visible by 123I-MIBG scanning before and 3 months after treatment as well as NSE and ferritin levels were studied. When the Student's T test was applied, we found statistically significant pre and post-treatment differences in 123I-MIBG scanning and NSE. In the case of ferritin, there was no statistical significance in spite of the decrease in the values. The direct correlation and Spearman correlation between laboratory data and 123I-MIBG scanning as well as correlation between NSE and ferritin were also studied. There was a good correlation between 123I-MIBG and NSE and between NSE and ferritin. We have also studied the data in 7 relapses. CONCLUSIONS: 123I-MIBG scintigraphy and serum determination of NSE are two successful diagnostic tools for the diagnosis and evolution of NB patients.

[Value of the use of the geometric mean to calculate the relative renal function in 99mTc-DMSA renal scintigraphy]. / Valor del uso de la media geométrica en el cálculo de la función renal relativa en la gammagrafía renal con 99mTc-DMSA.

Determining the relationship of DMSA uptake of the left versus right kidney is theoretically one of the easiest quantitative procedures in nuclear medicine. The quantification can be performed on the posterior view, with or without a lateral view for correction of kidney depth. The geometric mean can also be determined by using both the anterior and the posterior views. This study has aimed to evaluate if there are significant differences in the quantification of the renal function percentage using only the posterior view and the geometric mean. Furthermore, we evaluated to what extent the patient's age and diagnosis influenced these differences. We have proposed a work protocol in which we indicate which cases the geometric mean should be calculated in order to minimize the possible errors occurring when only the posterior view is used.A total of 328 renal scintigraphies with 99mTc-DMSA performed at our Department in the last six months were studied. The mean and standard deviation of the differences as well as the correlation coefficient between both methods were calculated. The difference between the right renal function in posterior view and the right renal function obtained using the geometric mean was calculated for all the patients. The Student's T test was applied to determine whether the differences between both methods were statistically different from zero. Statistical differences were found in patients older than 9 years and in patients with genitourinary malformations.