Association of angiomyolipoma and oncocytoma of the kidney: a case report and review of the literature. (25/183)

AIM: The association between renal carcinoma and angiomyolipoma is rare. Only 14 cases have been reported in the literature. The purpose of this paper is to present an additional case and review the literature on this association. PATIENT AND METHODS: A healthy 42 year old woman was found to have a left flank mass incidentally when she presented for a Papanicolaou smear. The computerised tomography scan revealed a left lower pole renal mass consistent with a renal cell carcinoma. A nephrectomy was performed and the patient recovered uneventfully. The nephrectomy specimen was processed routinely. In addition to haematoxylin and eosin staining, immunohistochemistry for CAM 5.2, vimentin, CD34, antismooth muscle actin, and HMB45 was carried out. Transmission electron microscopy was also performed. RESULTS: Macroscopically, the lower pole of the kidney contained a well circumscribed, non-encapsulated, tan coloured tumour with a large area of central haemorrhage measuring 10.5 cm. In addition, there was a 0.4 cm poorly circumscribed unencapsulated yellow nodule adjacent to the tumour. Microscopically, the larger tumour showed characteristic features of an oncocytoma. Numerous mitochondria were seen on electron microscopy. The smaller yellow nodule was an angiomyolipoma. CONCLUSIONS: This paper presents an additional case of oncocytoma associated with angiomyolipoma. Of the 15 cases described in the literature, three were associated with the tuberous sclerosis complex, all from a single study. In tuberous sclerosis, angiomyolipomas are more commonly associated with renal cell carcinoma. If angiomyolipomas are found incidentally in nephrectomy specimens together with other tumours, it is important to exclude tuberous sclerosis retrospectively.  (+info)

Mitochondrial complex I is deficient in renal oncocytomas. (26/183)

Renal oncocytomas are benign tumors characterized by dense accumulation of mitochondria the cause of which remains unknown so far. Consistently, mitochondrial DNA content and the amounts and catalytic activities of several oxidative phosphorylation (OXPHOS) complexes were known to be increased in these tumors, but it was not ascertained that the OXPHOS system was functional. Here we investigated mitochondrial complex I and found that its NADH dehydrogenase activity and protein content were specifically decreased in oncocytomas, in stark contrast with the parallel decrease of all respiratory chain complexes in other, malignant, renal tumors. We conclude that deficiency of complex I in oncocytomas might be the early event causing the increased mitochondrial biogenesis, attempting to compensate for the loss of OXPHOS function. Since other tumors were found to be linked to mitochondrial deficiencies like genetic alterations of fumarate hydratase or succinate dehydrogenase, oncocytoma could be the third type of benign tumor associated with impairment of mitochondrial ATP production in an oxidative, quiescent tissue. Besides, complex I enzyme activity was moderately decreased in the vicinity of oncocytomas, when compared with normal tissue adjacent to other renal tumors. This suggested that oncocytomas are the result of at least two serial modifications altering the mitochondrial respiratory chain.  (+info)

Postoperative findings and risk for malignancy in thyroid nodules with cytological diagnosis of the so-called "follicular neoplasm". (27/183)

BACKGROUND: Malignant follicular lesion is not differentiated from benign lesions cytologically. The objective of this study was to assess the rate and the risk of malignancy in thyroid nodules which were cytologically diagnosed as follicular neoplasm by fine-needle aspiration (FNA) cytology. METHODS: All the patients who had undergone surgery with cytological diagnosis of follicular neoplasm from January 1996 through December 2001 in Asan Medical Center were studied retrospectively. Patients' and nodule characteristics were analyzed for factors associated with the presence of cancer. Two hundred and fifteen patients (196 females, 19 males) were included and their mean age was 39.4 years (range: 12-76). RESULTS: About half of the patients (102 out of 215, 47.4%) had malignancy with 29 papillary carcinomas, 57 follicular carcinomas, 15 Hurthle cell carcinomas and 1 medullary carcinoma. Previously suggested factors associated with risk for malignancy, such as male gender, large tumor size (> 4 cm) or age of patients (> 45 years), were not associated with increased risk. Diagnosis of Hurthle cell neoplasia on FNA was also not associated with increased risk. Only the extremes in age of the patients (below 20 or above 60 years) were associated with increased risk for malignancy. CONCLUSION: In our findings, prevalence of carcinoma in thyroid nodule patients with cytological diagnosis of follicular neoplasm was much higher than those reported. Clinical characteristics, such as male gender, age and nodule size, are not useful predictors for the presence of malignancy. Thyroid nodules with cytological diagnosis of follicular neoplasm warrant immediate surgery.  (+info)

Inactivation of BHD in sporadic renal tumors. (28/183)

Studies of families with Birt-Hogg-Dube syndrome (BHD) have recently revealed protein-truncating mutations in the BHD gene, leading to tumorigenesis of the skin and of different cell types of kidney. To additionally evaluate the role of BHD in kidney tumorigenesis, we studied 39 sporadic renal tumors of different cell types: 7 renal oncocytomas, 9 chromophobe renal cell carcinomas (RCCs), 11 papillary RCCs, and 12 clear cell RCCs. We screened for BHD mutations and identified a novel somatic mutation in exon 13: c.1939_1966delinsT in a papillary RCC. We performed loss of heterozygosity (LOH) analysis on 28 matched normal/tumor sets, of which 10 of 28 (36%) demonstrated LOH: 2 of 6 (33%) chromophobe RCCs, 5 of 6 (83%) papillary RCCs, 3 of 12 (25%) clear cell RCCs, but 0 of 4 renal oncocytomas. BHD promoter methylation status was examined by a methylation-specific PCR assay of all of the tumors. Methylation was detected in 11 of 39 (28%) sporadic renal tumors: 2 of 7 (29%) renal oncocytomas, 1 of 9 (11%) chromophobe RCCs, 4 of 11 (36%) papillary RCCs, and 4 of 12 (33%) clear cell RCCs. Five tumors with methylation also exhibited LOH. Mutation and methylation were absent in 9 kidney cancer cell lines. Our results showed that somatic BHD mutations are rare in sporadic renal tumors. The alternatives, LOH and BHD promoter methylation, are the two possible inactivating mechanisms involved. In conclusion, unlike other hereditary kidney cancer-related genes (i.e., VHL and MET), which are cell type-specific, BHD is involved in the entire spectrum of histological types of renal tumors, suggesting its major role in kidney cancer tumorigenesis.  (+info)

18F-FDG PET of patients with Hurthle cell carcinoma. (29/183)

Hurthle cell carcinoma is an uncommon differentiated thyroid cancer characterized by an aggressive clinical course and low avidity for (131)I. Treatment usually involves an aggressive surgical approach often combined with (131)I. (18)F-FDG PET has been helpful in the staging and evaluation of many types of aggressive malignancy. No reports to date have described the utility of PET in a series of patients with Hurthle cell cancer. We reviewed our experience with (18)F-FDG PET in the care of patients with Hurthle cell carcinoma to determine the likelihood of uptake in these cancers and the effect of (18)F-FDG PET on patient care. METHODS: Patients with Hurthle cell cancer who were seen between June 2000 and April 2002 and were imaged with (18)F-FDG PET were included. Imaging and clinical data were reviewed. PET results were compared with the results of anatomic imaging (CT, sonography, or MRI) and (131)I imaging when performed. Patient charts were reviewed to identify any change in management that resulted from the (18)F-FDG PET findings. RESULTS: Fourteen (18)F-FDG PET scans of 12 patients were obtained in the time frame indicated. All patients had documented Hurthle cell carcinoma. PET showed intense (18)F-FDG uptake in all known Hurthle cell cancer lesions but one. PET showed disease not identified by other imaging methods in 7 of the 14 PET scans. PET identified distant metastatic disease (5) or local disease (2) that was more extensive than otherwise demonstrated. In 7 of the 14 scans, the information provided by PET was used to guide or change therapy. CONCLUSION: Hurthle cell carcinoma demonstrates intense uptake on (18)F-FDG PET images. PET improves disease detection and disease management in patients with Hurthle cell carcinoma relative to anatomic or iodine imaging. (18)F-FDG PET should be recommended for the evaluation and clinical management of patients with Hurthle cell carcinoma.  (+info)

Is [18F]-2-fluoro-2-deoxy-d-glucose (FDG) scintigraphy with non-dedicated positron emission tomography useful in the diagnostic management of suspected metastatic thyroid carcinoma in patients with no detectable radioiodine uptake? (30/183)

OBJECTIVE: Dedifferentiation of thyroid cancer leads to an inability of thyroid cells to concentrate iodine. In these cases, imaging methods that allow an accurate detection of recurrence and/or metastases at an early stage are essential for an adequate management of patients. Positron emission tomography using [18F]-2-fluoro-2-deoxy-d-glucose and a dedicated (dPET-FDG) or non-dedicated (nPET-FDG) camera has been suggested as a potential tool for the detection of tumour foci. DESIGN AND METHODS: This prospective study was undertaken to evaluate nPET-FDG in 51 consecutive patients (18 men, 33 women) with differentiated thyroid cancer (33 papillary, 11 follicular, four insular and three oncocytic (Hurthle-cell) thyroid carcinomas). Selection criteria were high thyroglobulin (Tg) levels (>10 ng/ml off-levothyroxine treatment) and no detectable radioiodine uptake, on a whole body scan performed with a high dose, in the absence of iodine contamination. RESULTS: Results were interpreted in terms of assumed presence of tumoral tIssue. Sensitivity of nPET-FDG was similar to that of conventional imaging modalities (67%). False negative nPET-FDG (n=16) were observed mostly in cases of micro-lesions (lymph nodes or lung metastases). Conversely, nPET-FDG identified new tumoral sites in 11 cases. Better sensitivity was found for nPET-FDG in patients with Tg levels higher than 15 microg/l (P<0.05). On a patient basis, results of nPET-FDG were equivalent to that of dPET-FDG. Finally, nPET-FDG changed treatment strategy in seven patients. CONCLUSIONS: nPET-FDG has a high sensitivity for the detection of tumour sites in patients when pathological iodine uptake cannot be demonstrated and appears to be a useful method in patients with elevated Tg levels, especially when dedicated PET is either unavailable or impractical.  (+info)

The investigation of galectin-3 in diseases of the thyroid gland. (31/183)

OBJECTIVE: Malignant tumors of the thyroid gland exhibit a variety of histopathologies and clinical behavior. Immune markers are gaining more and more importance in diagnostic pathology, especially in the differential diagnostics and in the grading of thyroid gland tumors. DESIGN: The Authors investigated the immunohistochemical reaction of galectin-3 (gal3) in patients with various thyroid gland diseases. They tested the diagnostic value of gal3 in determining the benign or malignant nature of various lesions, especially in lesions of follicular origin, because previous results have indicated nearly 100% specificity and sensitivity in this regard. METHODS: Gal3 immunoperoxidase reaction was carried out on 91 sections of thyroid gland samples fixed in formalin and embedded in paraffin. RESULTS: While gal3 expressed itself strongly and diffusely in papillary carcinomas (19 of 20 cases), in other malignant lesions it showed weaker, focal or variable positivity. Focal positivity was found in four of 19 follicular adenomas, and negativity was found in three of 10 follicular carcinomas. In all cases of inflammation a focal positivity was observed (eight of eight cases). All nodular goiter and normal thyroid tIssue were negative (25 of 25 cases). CONCLUSIONS: Based on our results, the gal3 immunohistochemical reaction seems to be reliable in the diagnosis of papillary carcinomas. However, in the case of solitary thyroid nodules and follicular lesions, although it is still a useful supplementary marker, it is not of absolute value (as stated in previous studies) in determining whether a tumor is benign or malignant.  (+info)

The usefulness of 99mTc-SestaMIBI scan in the diagnostic evaluation of thyroid nodules with oncocytic cytology. (32/183)

OBJECTIVE: To assess the relevance of (99m)Tc-SestaMIBI (MIBI) scan in the diagnostic evaluation of thyroid nodules with oncocytic cytology. SUBJECTS AND METHODS: Twenty-four patients with a single (or prevalent) 'cold' solid nodule with Hurthle cells (HC) at fine needle aspiration cytology (FNAC) were studied. Cytological diagnosis of oncocytic metaplasia (OM) or HC tumor (HCT) was made when HC on the smear were comprised 10-75%, or >75%. Nodules concentrating MIBI at early and late (2 h after washout) stages were considered MIBI-positive. In all cases histological findings were obtained after total thyroidectomy. RESULTS: FNAC was malignant or suspect for malignancy in 16 cases (six HCT and 10 OM) and not suspect in eight (two HCT and six OM). Histological examination revealed 14 malignant tumors (11 HCT and three OM), and 10 benign thyroid lesions (three HCT and seven OM). Sensitivity of FNAC for malignancy was 92.8% and specificity was 70.0%; HCT were identified by FNAC in only 35.7% and OM in 70.0% of cases. No significant difference in MIBI positivity was found between malignant and benign thyroid nodules. The highest percentage of MIBI positivity was found in HCT (78.5%), but MIBI-positive nodules were also observed in thyroid lesions with HC metaplasia (40.0%). CONCLUSIONS: MIBI scintiscan has no value in differentiating malignant from benign HC thyroid neoplasias. Most HCT are MIBI-positive, but this scan is not sufficiently specific to differentiate true HC neoplasias from other thyroid lesions showing HC at FNAC, although an MIBI-negative scan strongly supports the absence of true HCT.  (+info)