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Pheochromocytomas (PCCs) and paragangliomas (PGLs) are rare neuroendocrine tumors. PGLs can further be divided into sympathetic (sPGLs) and head-and-neck (HN-PGLs). There are virtually no treatment options, and no cure, for metastatic PCCs and PGLs (PPGLs). Here, we composed a tissue microarray (TMA) consisting of 149 PPGLs, reflecting clinical features, presenting as a useful resource. Mutations in the pseudohypoxic marker HIF-2α correlate to an aggressive tumor phenotype. We show that HIF-2α localized to the cytoplasm in PPGLs. This subcompartmentalized protein expression differed between tumor subtypes, and strongly correlated to proliferation. Half of all sPGLs were metastatic at time of diagnosis. Cytoplasmic HIF-2α was strongly expressed in metastatic sPGLs and predicted poor outcome in this subgroup. We propose that higher cytoplasmic HIF-2α expression could serve as a useful clinical marker to differentiate paragangliomas from pheochromocytomas, and may help predict outcome in sPGL patients. [ABSTRACT FROM AUTHOR]

Recurrent alterations in promoter methylation of tumor suppressor genes (TSGs) and LINE1 (L1RE1) repeat elements were previously reported in pheochromocytoma and abdominal paraganglioma. This study was undertaken to explore CpG methylation abnormalities in an extended tumor panel and assess possible relationships between metastatic disease and mutation status. CpG methylation was quantified by bisulfite pyrosequencing for selected TSG promoters and LINE1 repeats. Methylation indices above normal reference were observed for DCR2 (TNFRSF10D), CDH1, P16 (CDKN2A), RARB, and RASSF1A. Z-scores for overall TSG, and individual TSG methylation levels, but not LINE1, were significantly correlated with metastatic disease, paraganglioma, disease predisposition, or outcome. Most strikingly, P16 hypermethylation was strongly associated with SDHB mutation as opposed to RET/MEN2, VHL/VHL, or NF1-related disease. Parallel analyses of constitutional, tumor, and metastasis DNA implicate an order of events where constitutional SDHB mutations are followed by TSG hypermethylation and 1p loss in primary tumors, later transferred to metastatic tissue. In the combined material, P16 hypermethylation was prevalent in SDHB-mutated samples and was associated with short disease-related survival. The findings verify the previously reported importance of P16 and other TSG hypermethylation in an independent tumor series. Furthermore, a constitutional SDHB mutation is proposed to predispose for an epigenetic tumor phenotype occurring before the emanation of clinically recognized malignancy. [ABSTRACT FROM AUTHOR]

Background. Adrenal lesions in patients with extra-adrenal malignancy can be part of disseminated tumour disease, but may also be incidental, benign finding. Strict characterisation is therefore crucial, and may have profound effects on patient management. Purpose. To prospectively characterise and follow-up adrenal lesions in patients with extra-adrenal malignancy, stratified into those with past or concurrent malignancy, with or without metastases. Material and methods. All incidentally detected adrenal lesions identified at cross-sectional imaging during 18 months in a defined geographical region were prospectively reported. All adult oncologic patients with adrenal lesions were subjected to biochemical work-up and dedicated adrenal imaging for lesion characterisation, including a two year follow-up. Results. Benign adrenal lesions were found in 74% (29/39) of patients who had a history of extra-adrenal malignancy, in 53% (57/108) of those with concurrent extra-adrenal malignancy without metastatic disease and in 25% (27/109) in those with signs of metastatic disease. Conclusion. An adrenal lesion occurring in a patient with past malignancy has a high likelihood of representing a benign lesion, and even in patients with present signs of malignant disease at least one fourth to one half of such lesions are benign. Dedicated adrenal imaging including computed tomography attenuation measurements with wash-out characteristics, in addition to biochemical testing for adrenal dysfunction, is highly recommended in these cases, especially in patients without any other signs of metastatic spread. [ABSTRACT FROM AUTHOR]

Malignant pheochromocytomas/paragangliomas (PCs/PGs) often have distant metastases to the skeleton, liver, and lungs. Radionuclide therapy is valuable for treatment of disseminated tumor disease and could be used as adjuvant therapy after surgery. Patients with local and/or distant metastases of PC/PG should be investigated preoperatively by scintigraphy using both 123I-MIBG and 111In-DTPA-D-Phe1-octreotide, to evaluate the possibilities for radionuclide therapy (i.e., a dosimetric estimation of radiation dose to the tumor tissue versus critical normal tissues). Individual patient dose-planning should be performed. For patients in whom positive therapeutic effects are anticipated radionuclide therapy can be applied. Therapy with both 131I-MIBG and 177Lu-octreotate might be favorable in individual patients with lesions visualized by both metaiodobenzylguanidine (MIBG) and octreotide scintigraphy with enhanced therapeutic effects and reduced side effects. [ABSTRACT FROM AUTHOR]

A case of sporadic, histamine-producing gastric carcinoid with liver metastases is reported. The patient was treated with somatostatin analogue (octreotide) combined with cortisone and blockade of histamine receptors prior to surgery, which included subtotal gastrectomy, excision of lymph node metastases and superficial liver metastases. Residual liver metastases were injected with ethanol. These interventions markedly reduced the urinary excretion of the main histamine metabolite (MeImAA). Eighteen months later combined immuno- and chemotherapy was initiated due to tumour progression and recurrent hormonal symptoms with good clinical results over 12 months. Scintigraphy, using [sup 111] In-DTPA-D-Phe[sup 1] -octreotide, visualized somatostatin receptors (sstr) in primary tumour, lymph node metastases and liver metastases. The tissue/blood [sup 111] In concentration ratios of tumour biopsies were very high. Northern analyses confirmed expression of all subtypes of sstr[sub 1–5] . Immunocytochemically, tumour cells were strongly positive for chromogranin A, histamine and vesicular monoamine transporter (VMAT) 2 (histamine transporter), but negative for VMAT 1, suggesting an origin from gastric enterochromaffin-like cells. In primary tumour cell cultures, histamine, 5-HTP and 5-HIAA, but not 5-HT, could be detected in conditioned culture medium, indicating a defective decarboxylation of the tryptamine precursor. This rare case of histamine-producing gastric carcinoid demonstrates that excellent symptom relief can be achieved despite disseminated disease, if active, multimodal treatment strategy is instituted. The presence of high numbers of sstr in tumour tissue also raises the possibility of receptor-guided radiotherapy. [ABSTRACT FROM AUTHOR]