Complementary role of parathormone washout test to 99mTc-MIBI parathyroid scintigraphy and histopathologic analysis of cell types in parathyroid adenomas. / Gammagrafía paratiroidea con 99mTc-MIBI: valor complementario de la paratohormona en el aspirado y análisis histopatológico de los tipos de células en los adenomas paratiroideos.

OBJECTIVE: Parathyroid scintigraphy (PS) can be negative or equivocal (N/E) in a considerable number of cases with highly suspicious clinical findings and biochemical results for parathyroid adenoma (PA). The aims of this study were to investigate the complementary role of parathormone washout test (PWT) to PS in patients with primary hyperparathyroidism (PHPT) and evaluate histopathologic aspects of PAs in comparison with PS results. MATERIAL AND METHODS: Thirty-eight patients with PHPT referred for PS were included in the study. Seventeen patients had both scintigraphic and ultrasonographic findings concordant with PA (Group A). Twenty-one patients having N/E PS, but suspected lesions for PA on ultrasonography (US) formed Group B. PWT was performed for all patients and they underwent the surgical intervention. An adenoma was removed in all patients and the histopathologic cell characteristics were established. RESULTS: The tumor size on US was larger in those patients whose adenomas were seen on the PS (P<.001). The percentages of chief (or principal), oxyphilic and clear cells in PAs were not statistically different between the groups. Serum parathormone level and PWT were not statistically significant between Group A and Group B (P=.095 and P=.04, respectively). CONCLUSION: Although there is not a definitive threshold value, the sensitivity of PS increases with lesion size. While chief cell and oxyphilic cell content of PAs tend to deplete in N/E PS, clear cell rate increases substantially. Combining PS with both US and PWT increases the sensitivity of detection and localization of PAs.

Oncocytic papillary cystadenoma with prominent mucinous differentiation of parotid gland: A case report.

We describe the case of an oncocytic papillary cystadenoma with mucinous differentiation of the parotid gland in a 64-year-old male. Histologically, the tumor exhibited distinctive areas of intracystic papillary growth pattern with microcystic and macrocystic spaces containing mucinous secretions and small crystals. The cyst wall and papillary fronds were lined by oncocytic admixed with numerous mucocytes. Lymphoid tissue and invasive features were not identified. The tumor showed strong expression of CK7 and mammaglobin in oncocytes, and BRST-2 and MUC4 in mucocytes. p63, ER, PR, SOX10, DOG-1, and S100 stains were negative. No rearrangement of the MAML2 gene region or ETV6-NTRK3 fusion transcript was detected. The diagnosis of oncocytic papillary tumor with prominent mucinous differentiation is particularly problematic owing to the large number of potential mimics and should prompt consideration of appropriate molecular studies.

Oncocytic variant of malignant gastrointestinal neuroectodermal tumor: a potential diagnostic pitfall.

Malignant gastrointestinal neuroectodermal tumor (MGNET) is a very rare, aggressive malignant neoplasm that may occur in any location in the gastrointestinal tract. Malignant gastrointestinal neuroectodermal tumors typically consist of sheet-like to pseudopapillary proliferation of primitive-appearing epithelioid cells with a moderate amount of lightly eosinophilic cytoplasm, round nuclei and small nucleoli, often in association with osteoclast-like giant cells. By immunohistochemistry, these tumors show expression of S100 protein and SOX10, in the absence of expression of more specific melanocytic markers (eg, HMB45, Melan A). Genetically, malignant gastrointestinal neuroectodermal tumors are characterized by rearrangements of the EWSR1 or FUS genes with CREB1 or ATF1. We report a case of gastric malignant gastrointestinal neuroectodermal tumor occurring in a 46-year-old woman and showing striking oncocytic cytoplasmic change, a previously undescribed potential diagnostic pitfall. An initial needle biopsy showed large, eosinophilic cells with S100 protein and SOX10 expression and lacking expression of KIT, DOG1, Melan A, keratin, chromogranin, or smooth muscle actin, and was interpreted as representing a granular cell tumor. The subsequent excision specimen showed similar-appearing areas, but also contained small more primitive-appearing areas, lacking oncocytic change and having high nuclear grade and brisk mitotic activity. This resection specimen was initially diagnosed as a malignant granular cell tumor. However subsequent gene expression profiling studies showed an EWSR1-ATF1 fusion, confirmed with fluorescence in situ hybridization for EWSR1, and a final diagnosis of MGNET with oncocytic change was made. This case highlights a previously undescribed pitfall in the diagnosis of MGNET, oncocytic change, and suggests that MGNET should be included in the differential diagnosis for unusual oncocytic neoplasms of the gastrointestinal tract.

Urothelial carcinoma with oncocytic features: an extremely rare case presenting a diagnostic challenge in urine cytology.

Recognizing histological variants in urothelial carcinoma (UC) is important because some may be associated with different clinical outcomes and/or therapeutic approaches; being aware of unusual histological variants may also be crucial in preventing diagnostic misinterpretations. Histological variants based on cytoplasmic features, such as clear-cell, plasmacytoid, rhabdoid, and lipoid-rich variants, are described in invasive UC; however, these cytoplasmic features are not formally defined and not usually encountered in non-invasive UC. Oncocytic cytoplasm has not been well described in either invasive or non-invasive UC. Herein, we report an exceedingly rare case of UC with oncocytic features arising in the right renal pelvis, which presented a diagnostic challenge in urine cytology due to the relatively low nuclear-to-cytoplasmic ratio; however, it could definitively be diagnosed using histological specimens. UC diagnosis is based on the presence of papillary architecture and widespread p53 nuclear accumulation, suggesting malignancy. An oncocytic tumor is generally considered to be not actively dividing, as shown by the low Ki-67 labeling index in this case. In spite of the low proliferative activity, the possibility of intravesicle recurrence (IVR) should be considered since positive preoperative cytology of upper tract UC is a risk factor for IVR after nephroureterectomy.

Hurthle cells in fine needle aspiration cytology of the thyroid: a potential diagnostic dilemma?

Hurthle cells are not uncommonly encountered in thyroid fine needle aspiration cytology (FNAC) smears. They are easily recognized by their distinct cytomorphology in cytological preparations, i.e. large, polygonal cells displaying uniform, rounded nuclei, often prominent nucleoli and abundant granular cytoplasm. Hurthle cells can be seen in both non-neoplastic and neoplastic thyroid lesions which can pose diagnostic dilemma to cytopathologists, especially when the lesions are focally sampled. We describe a case of solitary thyroid nodule in a 46-year-old male, whose aspirates comprised predominantly of Hurthle cells exhibiting nuclear features suspicious of papillary carcinoma, which turned out to be Hurthle cell carcinoma on subsequent histological sections. The potential diagnostic pitfalls of Hurthle cell lesions and associated conditions in thyroid FNA are discussed. The presence of Hurthle cell change in a wide variety of thyroid lesions can be diagnostically challenging. However, accurate diagnosis can still be made with careful observation of the predominant cell population, nuclear features and whether there is abundant colloid or lymphocytes in the background.

Differential expression and regulation of Klotho by paricalcitol in the kidney, parathyroid, and aorta of uremic rats.

Klotho plays an important role in the pathogenesis of cardiovascular disease in chronic kidney disease (CKD). Klotho is highly expressed in the kidney and parathyroid glands, but its presence in the vasculature is debated. Renal Klotho is decreased in CKD, but the effect of uremia on Klotho in other tissues is not defined. The effect of vitamin D receptor activator therapy in CKD on the expression of Klotho in various tissues is also in debate. In uremic rats (surgical 5/6th nephrectomy model), we compared 3 months of treatment with and without paricalcitol on Klotho immunostaining in the kidney, parathyroid glands, and aorta. With uremia, Klotho was unchanged in the parathyroid, significantly decreased in the kidney (66%) and the intimal-medial area of the aorta (69%), and significantly increased in the adventitial area of the aorta (67%) compared with controls. Paricalcitol prevented the decrease of Klotho in the kidney, increased expression in the parathyroid (31%), had no effect in the aortic media, but blunted the increase of Klotho in the aortic adventitia. We propose that fibroblasts are responsible for the expression of Klotho in the adventitia. In hyperplastic human parathyroid tissue from uremic patients, Klotho was higher in oxyphil compared with chief cells. Thus, under our conditions of moderate CKD and mild-to-moderate hyperphosphatemia in rats, the differential expression of Klotho and its regulation by paricalcitol in uremia is tissue-dependent.

Oncocytic lesions of the neuroendocrine system.

This paper reviews the pathologic features of lesions which are oncocytic and involve classic endocrine organs. The history of the oncocytic cell, its morphologic and ultrastructural features, and important immunohistochemical findings are reviewed. Oncocytic proliferations including non-neoplastic and neoplastic of the thyroid, parathyroid, adrenal (both cortex and medulla), and pituitary are described. Their clinical relevance, functional capacity and capability, and where appropriate, prognostic implications are discussed. Important and relevant molecular biological information is included where appropriate.

A rare, human prostate oncocyte cell originates from the prostatic carcinoma (DU145) cell line.

DU145 human prostate carcinoma cells are typically poorly differentiated and contain only scantily distributed organelles. However, among numerous tumor cells randomly examined by electron microscopy out of in vitro cultivation, a peculiar, rare oncocyte-like cell type has been observed whose nucleus appears to be of small dimension and with a cytoplasm almost entirely filled with often distorted mitochondria. A few small, dispersed lysosomal bodies, small cisterns of the endoplasmic reticulum and a few glycogen patches can be found among highly osmiophilic contrasted, cytosolic spaces filled by innumerable ribonucleoproteins. The excessive population of mitochondria may have arisen from a more populated tumor cell type wherein the altered mitochondria are found to appear burgeoning into a spherical-like size progeny crowding the tumor cells. Literature cited between 1950 and the present suggests that this rare, oncocytic, benign prostatic tumor cell type is likely appear epigenetically, stemming from an original secretory cell, which is confirmed by the origin of the cell line originally maintained as cell line out of a brain metastatic, adenocarcinoma niche.

Morphological and immunocytochemical diagnosis of thyroiditis: Comparison between conventional and liquid-based cytology.

The efficacy of thyroid (FNAB) processed by liquid-based cytology (LBC) in Hashimoto's Thyroiditis (HT) in two reference periods, is evaluated. The morphologic features of 820 cases with both methods and the cyto-histological comparison are analyzed. The diagnosis of hyperplastic nodules (HN) in HT, its mimickers especially in presence of oxyphilic cells and the role of immunocytochemistry (IHC) are studied. 150 cases of HT processed by conventional smear (CS) in 1996-98 and 670 with LBC in 2005-2007,were included. The majority of FNAB were carried out under USguidance and fixed with ethyl alcohol for the CS. LBC material was rinsed in the Cytolit solution, processed according to the manufacturer's recommendations. Among the 150 CS, 83 were HT while 67 were HN in HT; in the second triennium 245 LBC were HT and 425 were HN in HT. In the first period a follow-up (including a second FNA or surgery) was done in 92 cases, in the second period in 116. In the surgical group 97.1% in the first period were benign (all HT and 34/36 HN) and 2.8% malignant(all HN). In 2005-2007, 94% were benign (15 HT and 45/49 HN) and 6%malignant. Thirty HN from the second triennium had ICC for HBME-1 and Galectin-3 resulting negative in 93.5%. Among these cases, 10 had a benign histology and a concordant negative ICC. LBC can be used as a valid method for HT, especially for the possible application of ICC to HN, and it allows a correct preoperative selection of lesions

Small oncocytic papillary renal cell carcinoma in diabetic glomerulosclerosis.

Histologic and immunohistochemical features of oncocytic papillary renal cell carcinoma (RCC) have not been fully elucidated. The author herein report a case of oncocytic papillary RCC (OPRCC). A 71-year-old man with diabetes mellitus and diabetic nephropathy was found to have a small right renal tumor by CT. He had been treated with hemodialysis for chronic renal failure for 10 years. A nephrectomy was performed. Grossly, a small (1.5cm) encapsulated yellow tumor was found in the kidney. Histologically, the tumor was completely encapsulated, and consisted entirely of atypical oncocytes arranged in a diffuse papillary structure with fibrovascular cores. The oncocytes showed grade 3 atypia and pseudostratification. A few mitotic figures were seen, and psammoma bodies, foamy macrophages, and hemosiderin were scattered. Histochemically, the tumor cells were positive for colloidal iron, and negative for mucins (Alcian blue/PAS). Immunohistochemical results of the tumor were as follows: α-methylacyl-coenzyme A rasemase (AMACR) +++, vimentin +++, cytokeratin (CK) 18 +++, CD10 +++, S-100 protein +, MUC1 ++, MUC2 ++, MUC5AC ++, MUC6 ++, panCK Cam5.2 +, CK7 +, CK8 +, CK14 +, CK19 +, CK20 +, p53 +, HepPar1 +, CD68 +, platelet-derived growth factor-α (PDGFRA) +, PanCK AE1/3 -, PanCK WSS -, PanCK MNF115 -, CK 35BE12 -, CK5/6 -, EMA -, desmin -, smooth muscle antigen -, α-fetoprotein -, CEA -, estrogen receptor -, progesterone receptor -, HER2 -, p63 -, and KIT -. Ki67 labeling was 6%. These results suggest that OPRCC can express colloidal iron, low molecular weight CKs, S100 protein, MUC1, MUC2, MUC5AC, MUC6, p53, PDGFRA, and HepPar1.

Possible association of CEA expression with oxyphilic change but not with C-cell hyperplasia in Hashimoto's thyroiditis.

Reactive C-cell hyperplasia (CCH) has been observed in cases of autoimmune Hashimoto's thyroiditis; however, its occurrence in Graves' disease, the other major autoimmune disorder, has not yet been investigated. On the other hand, although Carcinoembryonic Antigen (CEA) serum levels have been reported elevated in patients with autoimmune thyroid disease (ATD), the source of CEA production at the cellular level is not elucidated. The aim of this study was to evaluate CCH and CEA immunohistochemical expression and comparatively analyze them in 136 ATD cases (107 Hashimoto's and 29 Graves' disease cases) and 20 cases of nodular hyperplasia (NH). Immunohistochemistry using monoclonal antibodies to chromogranin and CEA was performed. A scoring system for CCH and semiquantitative evaluation for CEA expression were applied. C-cell hyperplasia was absent in NH cases. In contrast, it was detected in 11% of ATD cases being more frequently observed in Hashimoto's (12.1%) than Graves' disease (6.8%) CCH associated to male sex and older age of Hashimoto's patients. CEA was detected only in ATD cases (33.8%), in C-cells and in follicular cells as well, being more frequently detected in Graves' (44.8%) than Hashimoto's (30.8%) disease. An interesting finding was an emerging possible association of CEA expression with oxyphilic change but not with C-cell hyperplasia in Hashimoto's thyroiditis. No significant correlation was established between CCH and CEA follicular cell expression in neither disease. In conclusion, C-cell hyperplasia and CEA expression may be encountered in the setting of Hashimoto's thyroiditis and Graves' disease.

Pancreatic serous microcystic adenoma with extensive oncocytic change.

Herein is reported a case of pancreatic serous microcystic adenoma with extensive oncocytic change in a 73-year-old woman. Histologically the tumor consisted of numerous small cysts, separated by thin or broad fibrous septa. These cysts were lined with uniform cells having abundant eosinophilic granular cytoplasm, which was negatively or weakly stained with PAS. Immunohistochemically, the cyst-lining cells were positive for cytokeratin (CK) 7, CK19, MUC1, MUC6, alpha-inhibin, and neuron-specific enolase (NSE), and negative for CK8, CK20, MUC2, and MUC5AC; these immunoprofiles coincide with those of serous microcystic adenoma. Immunostaining with anti-mitochondrial antibody showed dense granular positivity in the cytoplasm, which suggested an oncocytic phenotype. Thus, this case is considered a variant of serous microcystic adenoma characterized by extensive oncocytic change. To the authors' knowledge no similar case has been reported in the literature. It may pose problems in the differential diagnosis of the cystic pancreatic tumors with oncocytic change, but can be diagnosed on histology and immunohistochemistry.

[Application of superparamagnetic iron oxide labeled antisense oligodeoxynucleotide probe in cellular magnetic resonance imaging].

OBJECTIVE: To prepare the superparamagnetic iron oxide (SPIO)-labeled antisense oligodeoxynucleotide (ASODN) probe and evaluate the application of this probe in cellular magnetic resonance imaging (MRI). METHODS: We prepared the SPIO-labeled ASODN probe using chemical cross linking method to conjugate SPIO to ASODN, detected its configuration by atomic force microscopy, determined the conjugating rate and biology activation by high performance liquid chromatography, and detected the stability by polyacrylamide gel electrophoresis. After that, we transfected the SK-Br3 oncocytes which had over-expression of the c-erbB2 oncogene by this probes, observed the intracellular iron distribution by optical microscope, measured iron content by atomic absorption spectroscopy, and observed the signal change by MRI. RESULTS: Atomic force microscope showed that the SPIO-labeled ASODN probe was mostly spherical and well-distributed, with a diameter of 25-40 nm and a conjugating rate of 100%. This probe had inhered biological activity and stability. In addition, light microscopy revealed an intracellular uptake of iron oxides in the transfected SK-Br3 oncocyte, and the iron content of the group of transfected SK-Br3 oncocytes was significantly higher than those of other contrast groups (all P < 0.01). MRI showed that transfected SK-Br3 oncocyte had the lowest signal among all other cells (all P < 0.05). CONCLUSIONS: We prepared the SPIO-labeled ASODN probe successfully. It can effectively transfect SK-Br3 oncocyte and enter SK-Br3 oncocyte, and thus reduce the signal intension in MRI.

Fine-needle aspiration biopsy of Hurthle cell lesions of the thyroid gland: A cytomorphologic study of 139 cases with statistical analysis.

BACKGROUND: Lesions of the thyroid gland composed of Hurthle cells encompass pathologic entities ranging from hyperplastic nodules with Hurthle cell metaplasia to Hurthle cell carcinomas. The cytologic distinction between these entities can be diagnostically challenging. Many cytologic features of Hurthle cell lesions that distinguish neoplastic Hurthle cell lesions requiring surgery from those that are benign and nonneoplastic have been described, but with variable usefulness. This is due, in part, to the small numbers of cases examined in previous studies and the limited application of statistical analysis. A morphologic study was made of 139 Hurthle cell lesions of the thyroid gland and statistical analysis applied to identify a set of cytomorphologic features that distinguish benign Hurthle cell lesions (BHCL) from Hurthle cell neoplasms (HCN). METHODS: Fine-needle aspiration biopsies (FNABs) of thyroid nodules with a predominant Hurthle cell component and corresponding histologic followup were included in the study. Cases were divided into BHCL and HCN groups on the basis of the histologic diagnosis. All cases were reviewed to assess the following 14 cytologic features: overall cellularity, cytoarchitecture, percentage of Hurthle cells, percentage of single cells, percentage of follicular cells observed as naked Hurthle cell nuclei, background colloid, chronic inflammation, cystic change, transgressing blood vessels (TBV), intracytoplasmic lumina, presence of multinucleated Hurthle cells, nuclear to cytoplasmic ratio, nuclear pleomorphism/atypia, and nucleolar prominence. The results were evaluated by using univariate and stepwise logistic regression (SLR) analysis; statistical significance was achieved at P-values < 0.05. RESULTS: One hundred thirty-nine FNAB specimens, corresponding to 56 HCN and 83 BHCL, fulfilled the study criteria. Six of the 14 cytologic features evaluated were shown by univariate analysis to be statistically significant in predicting HCN: nonmacrofollicular architecture (P < 0.001), absence of background colloid (P < 0.001), absence of chronic inflammation (P < 0.001), presence of TBV (P < 0.001), > 90% Hurthle cells (P < 0.001), and >10% single Hurthle cells (P = 0.014). The first four of these features were also shown to be statistically significant in the SLR analysis (P = 0.005, 0.010, 0.016, and 0.045, respectively), and when all four of these features were present HCN was correctly identified 86% of the time. CONCLUSIONS: In the current study of 139 FNAB specimens of thyroid Hurthle cell nodules, 14 cytologic features were examined and 6 were found to be statistically significant in identifying HCN. The following four features, when found in combination, were found to be highly predictive of HCN: nonmacrofollicular architecture, absence of colloid, absence of inflammation, and presence of TBV.

Oncocytic adrenocortical carcinomas: a pathological and immunohistochemical study of four cases in comparison with conventional adrenocortical carcinomas.

Clinicopathological features of four cases of oncocytic adrenocortical carcinomas were studied. All tumors were large, circumscribed tumors with average size and weight of 11.5 cm and 586 g, respectively. The cut surfaces were yellow or brown and tan with areas of hemorrhage, necrosis, fibrosis, myxoid and cystic change. The tumor cells were exclusively oncocytic with a diffuse or compact and solid arrangement. Nuclear atypia was identified but mitosis was rare. Capsular invasion was identified in all tumors and vascular invasion was identified in one tumor. All tumors were immunoreactive for vimentin and inhibins. Immunoreactivity for pancytokeratin, synaptophysin and S-100 protein was variable and focal. All tumors had low proliferative indices, of less than 1%, and were negative for p53 protein. Ultrastructurally, the cytoplasm of tumor cells showed numerous mitochondria in a compact arrangement. Oncocytic adrenocortical carcinomas showed a similar sex ratio, slightly older mean age, similar left predilection, slightly smaller size and lighter weight compared with the conventional carcinomas. We suggest that most oncocytic adrenocortical carcinomas might be low-grade malignancies with less aggressive histological features compared with conventional carcinomas. However, they should be excised completely because of the likelihood of recurrence and metastasis during the follow-up period.

Breast tumor resembling the tall cell variant of papillary thyroid carcinoma: report of 5 cases.

Five cases of a hitherto undescribed breast tumor having histologic features similar to those of the tall cell variant papillary thyroid carcinoma are described. They were composed of columnar mitochondrion-rich to oxyphilic cells arranged in nests, papillae, and follicle-like structures. In addition, the neoplastic cells showed numerous nuclear grooves and, in two cases, nuclear pseudo-inclusions. None of the patients had previous concomitant or subsequent evidence of a thyroid tumor. Immunohistochemistry further excluded a metastasis from the thyroid in the four cases tested, as they were consistently thyroglobulin and thyroid transcription factor 1 negative.

[Diagnosis of the follicular variant of papillary thyroid carcinoma. Significance of immunohistochemistry]. / Diagnostic de la variante vésiculaire du carcinome papillaire de la thyroïde. Intérêt de l'immunohistochimie.

AIMS: To study the expression of cytokeratin 19 (CK-19), HBME-1 and Ret in follicular-patterned thyroid tumors, and their significance for the diagnosis of the follicular variant of papillary thyroid carcinoma. MATERIALS AND METHODS: 111 well-differentiated follicular tumors were examined by immunohistochemistry: 59 papillary carcinomas (43 of the follicular variant), 40 follicular adenomas (among which 11 atypical adenomas), 10 oxyphil cell tumors and 2 follicular carcinomas. RESULTS: CK-19 was diffusely expressed in all the papillary carcinomas, and was also expressed in 2/4 oxyphil cell carcinomas and 4/11 atypical adenomas. 90% of the follicular adenomas (26/29), the six oxyphil cell adenomas and the two follicular carcinomas showed at best a focal staining of dystrophic areas. 78% of the papillary carcinomas and 3/11 atypical adenomas were stained with HBME-1, whereas 26/29 adenomas (90%) and the 10 oxyphil cell tumors were negative. 34% of the papillary carcinomas expressed Ret (most of them were of the usual type (14/20)). The staining was often weak and focal (13/20). The other tumors were all negative for Ret. CONCLUSIONS: CK-19 is a sensitive (100%) and specific (82.5%) marker of papillary carcinomas, which can be helpful in the diagnosis of its follicular variant. HBME-1 can improve this specificity when associated with CK-19. The Ret protein expression is of limited practical interest.

Epithelioid leiomyosarcoma of the uterus with oncocytic change.

We report on a rare case of epithelioid leiomyosarcoma of the uterus with oncocytic change and aggressive clinical behavior. The tumor arose in the left lateral wall of the uterus and measured 22 cm in greatest dimension. Histologically, it consisted of solid sheets of round and polygonal cells displaying a homogeneously eosinophilic cytoplasm and pleomorphic nuclei with prominent nucleoli. Six mitotic figures were found per 10 high-power fields in the most mitotically active areas, and focal tumor cell necrosis was present elsewhere. Under electron microscopy, numerous normal-appearing mitochondria and occasional bundles of microfilaments with focal densities were noted in the tumor cell cytoplasm, and poorly-formed external basal lamina and occasional pinocytic vesicles were found on the cell membrane of some tumor cells.