Incidental langerhans cell histiocytosis of thyroid: case report and review of the literature

We report a case of a 42-yr-old woman with Langerhans cell histiocytosis (LCH) confined to the thyroid and associated with lymphocytic thyroiditis and a papillary microcarcinoma. This patient remains free of symptoms 14 mo after surgery. Thyroid LCH is rare. In children, it usually occurs as part of a multisystemic disease, whereas it is usually exclusive in adults. Isolated thyroid LCH is frequently associated with another thyroid disease, especially lymphocytic thyroiditis, suggesting that it is a reactive process rather than a neoplastic proliferation. The prognosis of isolated thyroid LCH is good. However, because it can rarely precede or reveal a multisystemic disease, additional investigations as well as a prolonged follow-up are justified.     

Intravascular lymphoma: report of two autopsic cases, literature review

Intravacular large B-cell lymphoma (LIV) is a rare entity individualized in the WHO classification since 2001 as a subtype of extranodal diffuse large B-cell lymphoma. We report two autopsic cases of LIV: a 77-year-old woman presenting with fever, dyspnea, antehypophyseal failure and a 54-year-old man presenting with fever, weight-loss, night-sweats and encephalopathy. They died respectively 10 and 7 months after the beginning of symptoms, without diagnosis. Neither infectious disease nor lymphomatous proliferation had been identified. From these two cases and our literature review, we insist on the importance of histopathological diagnosis on biopsy for this rare pathology which clinical diagnosis remains difficult.     

No evidence of thyrotropin receptor and G(s alpha) gene mutation in high iodine uptake thyroid carcinoma.

Usually, thyroid carcinoma presents as a cold nodule on radioiodine scintigraphy. High-uptake nodules on iodine thyroid scans are associated with an exceedingly low incidence of malignancy. Only 29 cases of carcinomas appearing as hot or warm nodules have as yet been reported. From 1993 to 1999, we have observed eight similar cases (4 hot and 4 warm thyroid nodules) suggesting that thyroid carcinomas may not be as rare as usually considered in these circumstances. Four tumors were available for molecular analysis on paraffin-embedded sections. Because no mutations were found in the whole coding portions of thyrotropin-receptor (TSH-R) gene and fragments encompassing the mutational hot spots of the G(s alpha) gene, it is unlikely that activating mutations of the TSH-R or G(s alpha) genes were involved in these carcinomas.     

Fatal outcome after reactivation of inherited chromosomally integrated HHV‐6A (iciHHV‐6A) transmitted through liver transplantation

HHV‐6A and HHV‐6B are found as inherited and chromosomally integrated forms (iciHHV‐6A and ‐6B) into all germinal and somatic cells and vertically transmitted in a Mendelian manner in about 1% of the population. They were occasionally shown to be horizontally transmitted through hematopoietic stem cell transplantation. Here, we present a clinical case of horizontal transmission of iciHHV‐6A from donor to recipient through liver transplantation. Molecular analysis performed on three viral genes (7.2 kb) in the recipient and donor samples supports transmission of iciHHV‐6A from the graft. Transmission was followed by reactivation, with high viral loads in several compartments. The infection was uncontrollable, leading to severe disease and death, despite antiviral treatments and the absence of resistance mutations. This case highlights the fact that physicians should be aware of the possible horizontal transmission of iciHHV‐6 and its consequences in case of reactivation in immunocompromised patients.     

Cushing's Syndrome Caused by a Well-Differentiated Ileal Neuroendocrine Carcinoma

We report a very rare case of Cushing’s syndrome caused by an ileal adrenocorticotrophin-secreting well-differentiated endocrine carcinoma with liver metastases. A 62-yr-old woman presented with clinical and biological signs suggestive of paraneoplastic Cushing’s syndrome. Radiological investigations, including magnetic resonance imaging of the pituitary gland, chest and abdominal computerized tomography scan, small bowel barium study and pancreatic endoscopic scan, 111-pentetreotide scintigraphy (octreoscan), esogastroduodenoscopy, and colonoscopy did not detect the source of the ectopic adrenocorticotropic hormone (ACTH) secretion but showed a few liver nodules. Because a 10-mo-long ketoconazole treatment was not effective, a bilateral adrenalectomy was performed in order to control the Cushing’s syndrome, and a liver nodule biopsy diagnosed a metastatic neuroendocrine tumor. Subsequently, a second laparotomy disclosed a 1.8 cm ileal neuroendocrine tumor, cosecreting ACTH and serotonin on immunohistochemistry with many liver metastases. ACTH secretion by intestinal neuroendocrine tumors is rare, and the secretion is almost always clinically silent. Cushing’s syndrome caused by an intestinal low-grade neuroendocrine tumor is even rarer, with only two previous cases reported in the literature. Our observation underlines the difficulty of localizing the source of ectopic ACTH secretion in paraneoplastic Cushing’s syndrome.     

Successful management of an aortoesophageal fistula using a cryopreserved arterial allograft

We report a case of aortoesophageal fistula occurring as a complication of colonic esophagoplasty. Emergency treatment during the hemorrhagic phase combined aortic replacement using a cryopreserved arterial allograft and digestive tract exclusion. Immediate recovery and follow-up at 8 months were good. This is the first reported case of successful in situ aortic replacement using a cryopreserved allograft for an aortoesophageal fistula. The lack of previous reports of successful treatment and related treatment modalities are discussed.     

Transcriptional profiling reveals coordinated up-regulation of oxidative metabolism genes in thyroid oncocytic tumors

Oncocytomas are large cell tumors characterized by an abnormal proliferation of mitochondria. To investigate this phenomenon in thyroid oncocytomas, we determined gene expression profiles of 87 samples using microarrays of 6720 PCR products from cDNA clones. Samples included 29 thyroid oncocytomas and six papillary carcinomas, the remainder representing other thyroid pathologies or mitochondria-rich tumor samples, normal thyroid samples, and two thyroid cell lines. Hierarchical clustering and supervised analysis identified two specific oncocytic clusters and 163 distinctly regulated genes between oncocytoma and normal thyroid. Differential expression of five selected genes (APOD, BCL-2, COX, CTSB, and MAP2) was confirmed by immunohistochemistry. The two specific oncocytic clusters were rich in mitochondrial genes and revealed coordinated expression of nuclear and mitochondrial respiratory chain genes. We also observed the up-regulation of genes involved in mitochondrial biogenesis, such as nuclear respiratory factor 1 and the endothelial nitric oxide synthase. Several oxidative metabolism genes were overexpressed in oncocytomas, including those from the tricarboxylic acid cycle (MDH1) and cytosolic glycolysis (GAPD, ENO1, and GPI). On the contrary, the lactate dehydrogenase A gene, involved in anaerobic metabolism, was down-regulated. Our results suggest that, unlike a large number of solid tumors, thyroid oncocytomas produce energy through an aerobic pathway.