The Role of Radiopharmaceuticals MIBG and (V) DMSA in the Diagnosis of Medullary Thyroid Carcinoma

The diagnostic value of 123/131I meta-iodo-benzylguanidine (MIBG) and 99mTc (V) dimercaptosuccinic acid (DMSA) was investigated in 12 patients with proven medullary thyroid carcinoma (MTC). Scintigraphic imaging with DMSA was negalive in nine of 12 patients. Scintigraphy with MIBG was positive in only one case. In proven primary or recurrent disease, DMSA sensitivity was 50% and MIBG sensitivity was 25%. Such sensitivities become much lower in subjects wilh high calcitonin (CT) levels who have had negative surgical explorations: DMSA 17% and MIBG 0%. DMSA delected tumor in 25% of the patients and MIBG in only 8%. The positivity of these scintigraphies appears to be unrelated to carcinoembryonic antigen and CT plasma levels. Such data suggest that scintigraphies wilh MIBG and DMSA are only modestly useful in the diagnosis of MTC

Evaluation of Children with Medullary Thyroid Carcinoma

Early diagnosis and surgical treatment of medullary thyroid carcinoma (MTC) in children is essential to decrease the likelihood of metastatic spread. From 1981 to 1991, eight children under 18 years of age (five girls and three boys) with MTC were seen and seven underwent total thyroidectomy. Followup ranged from 14 months to 10 years after surgery. Four of the seven presented with a neck mass and elevated basal levels of calcitonin (CT). After surgery, three had recurrent disease. In the other three, the diagnosis was made after several years of screening (normal basal values of CT but increased CT levels after calcium/pentagastrin infusion). All had normal stimulated CT values postoperatively. This follow-up showed that the prognosis for MTC in children depends predominantly upon its extent at the time of the diagnosis and treatment

trabecular bone score tbs and bone metabolism in patients affected with type 1 neurofibromatosis nf1

In patients with neurofibromatosis type 1 (NF1), decreased bone mineral density (BMD) and low levels of 25-hydroxy vitamin D3 (25OHD) have been reported. Recently, the trabecular bone score (TBS) measurement has been proposed as index of bone microarchitecture and fracture risk. In 74 NF1 patients (48 females, 26 males, age 41 ± 12), we measured TBS and investigated clinical stage, lifestyle, vitamin D, serum bone turnover markers, vertebral and femoral BMD. A homogenous cohort of 61 healthy subjects was used as control group. TBS was lower in NF1 patients (1.266 ± 0.113 vs. 1.346 ± 0.105) without differences between sexes. No correlations with 25OHD, low exercise, low calcium intake, reduced sun exposure, and number of skin neurofibromas were observed. As expected, hypovitaminosis D was common (98.6%), as well as BMD reduction in hip and spine sites: In NF1 patients, bone texture evaluated by TBS was low in both sexes without any correlation with clinical or metabolic parameters, suggesting a direct role of the fibromin mutation

Use of Somatostatin Analog SMS 201-995 in Medullary Thyroid Carcinoma

We have studied seven subjects with medullary thyroid carcinoma. Each had elevated basal serum calcitonin (CT) levels following total thyroidectomy. After subcutaneous administration of 100 μg of SMS 201-995, blood samples were collected at 60-minute intervals for six hours. Two patients showed a marked decrease of CT levels (patient A: baseline 565 μg/mL, nadir 150 μg/mL; patient B: baseline 1,632 μg/mL, nadir 416 μg/mL). The other five patients showed no significant change in comparison with saline infusion. Two patients were treated with SMS 201-995 (300 μg/day)for 90 days. One of these patients responded to the acute SMS 201-995 test and had CT levels persistently 50% lower than pretreatment values during this 90-day period. The other patient, whose CT levels did not decrease during the acute test, had persistently high values during this 90-day period but had relief of watery diarrhea even after the therapeutic trial was discontinued

Growth hormone-releasing hormone-producing pancreatic neuroendocrine tumor in a multiple endocrine neoplasia type 1 family with an uncommon phenotype

The objective of this study was to describe a multiple endocrine neoplasia type 1 (MEN1) family characterized by primary hyperparathyroidism, in association with acromegaly because of ectopic growth hormone-releasing hormone (GHRH) secretion by a pancreatic neuroendocrine tumor in a young man and with a bronchial carcinoid in his mother. We investigate the clinical, radiological imaging, histopathologic findings, and therapy. An 18-year-old man successfully underwent subtotal parathyroidectomy for primary hyperparathyroidism. A subsequent genetic analysis showed a MEN1 gene mutation. Three years later, acromegaly because of ectopic GHRH secretion was diagnosed (pituitary MRI negative and elevated GHRH levels). A search for an ectopic tumor was unsuccessful and somatostatin analog therapy was started. Successively, scintigraphy with somatostatin analogs (68-Ga-DOTATOC-PET) showed three focal areas in the pancreatic tail. Distal pancreatectomy showed multiple pancreatic neuroendocrine tumors and hormonal status was normalized. Afterwards, the evaluation of the patient's mother, carrying the same mutation, indicated a primary hyperparathyroidism and a 4 cm lung mass. The patient underwent subtotal pneumonectomy and the histological analysis was consistent with the diagnosis of a typical bronchial carcinoid. In conclusion, an atypical phenotype may be recorded in MEN1 families, thus emphasizing the importance of the new imaging and surgical techniques in the diagnosis and treatment of such a rare disease