[Langerhans cell histiocytosis of the dens axis]. / Langerhanscelhistiocytose van de dens axis.

BACKGROUND: Langerhans cell histiocytosis, formerly known as histiocytosis X, is characterised by clonal proliferation of pathologic cells resembling Langerhans cells. Langerhans cell histiocytosis is commonly localised in the bones of the skull or in the skin; however, a great variety of foci has been described. CASE: A general practitioner referred a 25-year-old man to the neurologist because of progressive pain in the neck that had arisen spontaneously. The pain had become so severe over a period of 3 weeks that he had had to support his head with both hands to ease it. Chiropractic treatment had resulted in a worsening of the symptoms. On physical examination, two pathologically enlarged lymph nodes were palpable on the left side of the neck. CT, MRI and PET scans revealed an osteolytic lesion at the site of the dens axis (C2). Immunohistochemistry of the lymph node demonstrated positive staining for CD1a and S100, characteristic of Langerhans cell histiocytosis. The patient was treated with chemotherapy and osteosynthesis of the C1-C2-C3 vertebrae; he was able to return to work after 9 months. CONCLUSION: Langerhans cell histiocytosis is an extremely rare condition; its diagnosis is often missed or made at a later time. The golden diagnostic standard is histopathological analysis of the abnormality. The condition's prognosis is related to its extent. Its localisation in the dens axis has not been previously described.

Endocrine tumours of the gastrointestinal tract. Peptide receptor radionuclide therapy.

Peptide receptor radionuclide therapy is a new treatment modality for patients with inoperable or metastasised neuroendocrine gastroenteropancreatic tumours. After the successful implementation of somatostatin receptor scintigraphy in daily clinical practice, the next logical step was to increase the radiation dose of the administered radiolabelled somatostatin analogue in an attempt to induce tumour shrinkage. Since then, an increasing number of patients has been successfully treated with this approach, resulting in a substantial numbers of patient with objective tumour shrinkage. Serious side-effects have been rare. This article reviews the effectiveness of the different radiolabelled somatostatin analogues used, the currently known side-effects and the survival data available. Furthermore, clinical issues, including indication and timing of therapy, are discussed. Finally, important directions for future research are briefly mentioned to illustrate that, although the currently available results already suggest a favourable outcome compared with other systemic therapies, new strategies are being developed to increase efficacy.

Radiolabeled somatostatin analog [177Lu-DOTA0,Tyr3]octreotate in patients with endocrine gastroenteropancreatic tumors.

PURPOSE: There are few treatment options for patients with metastasized or inoperable endocrine gastroenteropancreatic (GEP) tumors. Chemotherapy can be effective, but the response is usually less than 1 year. Here, we present the results of treatment with a radiolabeled somatostatin analog, [177Lu-DOTA0,Tyr3]octreotate (177Lu-octreotate). PATIENTS AND METHODS: One hundred thirty-one patients with somatostatin receptor-positive tumors were treated with up to a cumulative dose of 600 to 800 mCi (22.2 to 29.6 GBq) of 177Lu-octreotate. RESULTS: One patient developed renal insufficiency, and another patient developed hepatorenal syndrome. Creatinine clearance did not change significantly in the other patients. WHO hematologic toxicity grade 3 or 4 occurred after less than 2% of the administrations. We observed complete remission in three patients (2%), partial remission in 32 patients (26%), minor response (tumor diameter decrease of 25% to 50%) in 24 patients (19%), stable disease (SD) in 44 patients (35%), and progressive disease (PD) in 22 patients (18%). Higher remission rates were positively correlated with high uptake on pretherapy somatostatin receptor imaging and a limited number of liver metastases, whereas PD was significantly more frequent in patients with a low performance score and extensive disease. Median time to progression in 103 patients who either had SD or tumor regression was more than 36 months. CONCLUSION: Treatment with 177Lu-octreotate results in tumor remission in a high percentage of patients with GEP tumors. Serious side effects are rare. The median time to progression compares favorably with chemotherapy. Results are better in patients with a limited tumor load. Therefore, early treatment, even in patients who have no PD, may be better.

Liver and vertebral uptake of Tc-99m macroaggregated albumin (MAA).

An unusual phenomenon during lung scintigraphy is presented. Besides visualization of the lungs, accumulation of Tc-99m macroaggregated albumin (MAA) was seen in a small part of the liver and in and around several thoracic vertebrae. Contrast-enhanced radiographic computed tomography revealed extensive collateral pathways, which were caused by a partially obstructed superior vena cava. Shunting of systemic venous blood flow through chest wall veins to the portal system was responsible for accumulation of MAA in the liver. Retrograde blood flow through dilated thoracic vertebral veins resulted in visualization of the bone marrow.