The importance of the unsuppressed glands in the study of intact parathyroid hormone disappearance after parathyroid adenomectomy.

BACKGROUND: In the usual techniques for intraoperative intact parathyroid hormone (iPTH) monitoring for primary hyperparathyroidism, the normal glands are implicitly considered suppressed. On the contrary, we believe, as do other researchers, that they are not totally suppressed. METHODS: For this reason, we considered the introduction of an infusion from the unsuppressed normal glands (UNG), described by an influx constant (IC (pg/ml per min)), into the formulation of a two-compartment model. For the blood compartment, we have: C(t)=A.exp(-at)+B.exp(-bt)+EV, where A+B+EV=iPTH concentration at zero time (clamping), EV (equilibrium value)=IC/k, 'a' and 'b' are reciprocals of the time constants of the two exponentials and k=rate constant of elimination from the blood. The experimental data were obtained using an IRMA standard method, collecting samples in 20 patients, during and following adenomectomy. RESULTS: In spite of the variability among the patients, all fits were very good, thus confirming the importance of the UNG contribution to the shaping of the disappearance curve. For this reason, the relationship between the constant infusion from the UNG and the basal iPTH level at the induction of anaesthesia (BV), was studied. CONCLUSIONS: The existence of a negative correlation, together with the determination of a regression curve (IC=6.5BV), not only confirmed our assumptions, but also revealed the theoretical possibility of a priori knowledge of the iPTH contribution from the UNG. Hence, there is a theoretical possibility of discriminating between this contribution and that of the remaining (if any) affected gland(s).

Microencapsulation of human parathyroid cells: an "in vitro" study.

BACKGROUND: Patients affected by hypoparathyroidism of variable etiology are currently treated with exogenously administered vitamin D and calcium. Human parathyroid transplantation has long been investigated as a possible mean of treating these patients to prevent long-term hypocalcemia. However, the main obstacle for this treatment is represented by tissue rejection. A reliable method to efficiently protect the transplanted tissue from rejection and to allow long-term survival of the graft is the encapsulation of tissues or cells in alginate-polylysine-alginate membranes, which were successfully used for encapsulation of islets of Langerhans. The microencapsulation of parathyroid tissue fragments or of parathyroid cells becomes, therefore, a potential approach for the successful treatment of permanent symptomatic hypoparathyroidism without pharmacological immunosuppression. MATERIALS AND METHODS: We describe microencapsulation of differentiated human parathyroid cells derived from adenoma or hyperplastic glands. Long-term viability, cell growth, and parathyroid hormone production of microencapsulated cells were evaluated together with responsiveness to extracellular Ca(2+). RESULTS: Microencapsulated parathyroid cells maintained proliferative and differentiative properties for a long term in culture with a good response to extracellular Ca(2+) concentration. CONCLUSIONS: These findings represent a crucial step toward the construction of functional bioartificial parathyroid organoids for the treatment of hypoparathyroidism in humans.

Parathyroid glands: combination of (99m)Tc MIBI scintigraphy and US for demonstration of parathyroid glands and nodules.

PURPOSE: To determine the appropriate choice of imaging techniques for localization of nodular lesions of parathyroid glands. MATERIALS AND METHODS: First, computed tomographic (CT), magnetic resonance (MR), ultrasonographic (US), and technetium 99m methoxyisobutyl-isonitrile (MIBI) scintigraphic images in 49 patients with primary hyperparathyroidism were retrospectively evaluated. A single-blind, prospective study that included 16 patients with primary hyperparathyroidism was then conducted. MR, US, scintigraphic, and color Doppler US images of the neck were obtained and analyzed. RESULTS: In the retrospective study, CT, MR imaging, and US had low sensitivity (13%, 17%, and 27%, respectively) and specificity (39%, 65%, and 65%, respectively). Scintigraphy had 57% sensitivity and 85% specificity. In the prospective study, the use of latest-generation MR and US equipment and the participation of experienced operators led to improved sensitivity and specificity for these techniques. The combination of US and scintigraphy resulted in improved sensitivity (96%), specificity (83%), and positive and negative predictive values (88% and 94%, respectively), relative to the results obtained with either method alone. Doppler US was of little help in the setting of small glands. CONCLUSIONS: The combination of (99m)Tc MIBI scintigraphy and US performed by well-trained operators with up-to-date instruments appeared to be the best diagnostic tool for the preoperative diagnosis of parathyroid disease.

Intraoperative fall in plasma levels of intact parathyroid hormone in patients undergoing parathyroid adenomectomy.

Intraoperative measurement of intact parathyroid hormone (PTH) can be used to evaluate the success of parathyroid surgery in primary hyperparathyroidism associated with parathyroid adenoma. To evaluate this approach we used a modified immunoradiometric assay (IRMA) to study the kinetic patterns of circulating PTH disappearance in 13 patients undergoing adenomectomy for single adenoma. The rapid and the standard assay for PTH measurement in plasma were used and compared. The two methods showed a highly significant correlation (r = 0.995; p < 0.0001). We reported a decrease in PTH to 18.2 +/- 2.30 (mean +/- SEM) from baseline values at 15 minutes after successful parathyroid adenomectomy in the 13 patients. The biphasic pattern of serum PTH clearance was calculated in 8 of the studied patients with a fast phase showing a half-life (T1/2) of 3.99 (SEM 0.464) minutes and a slow phase with a T1/2 of 91.0 (SEM 33.6) minutes. Half the amount of the basal values was reached between 4 and 9 minutes. Our study concludes that the modified IRMA for intraoperative measurement is feasible, reliable and sufficiently precise for low hormone values. Since it may yield information on the half-life of PTH in the circulation, it may play a role in the surgical guidance for total exeresis of hyperfunctioning tissue.

Oral Crohn's disease and pyostomatitis vegetans. An unusual association.

Oral features of Crohn's disease include ulcers, lip fissuring, cobblestone plaques, angular cheilitis, polypoid lesions, and perioral erythema. Pyostomatitis vegetans is a rare eruption of the oral mucosa characterized by tiny yellow pustules. It is considered a marker for inflammatory bowel disease. We describe a 45-year-old woman with a 6-month history of painful sores in her mouth, diarrhea, weight loss, and cutaneous lesions. Oral examination revealed cobblestone plaques and indentation on the tongue and friable vegetating pustules on the labial commissures. Staphylococcus simulans was isolated from the pustules. Laboratory studies revealed leucocytosis, eosinophilia, and low hemoglobin and zinc levels. Histologic study of the labial lesions revealed hyperplastic epithelium with intraepithelial clefts that contain eosinophils and neutrophils. Tongue lesions showed chronic inflammation with noncaseating granulomas. Later, colonoscopy and biopsy demonstrated Crohn's disease of the anorectal region. Pyostomatitis vegetans lesions regressed after oral zinc supplementation. Prednisone treatment resulted in healing of the tongue lesions. In our patient, pyostomatitis vegetans appeared to be related to zinc deficiency that may have been caused by malabsorption. The pathogenetic interrelationship between pyostomatitis vegetans and Crohn's disease is discussed.

Progression of uremic hyperparathyroidism involves allelic loss on chromosome 11.

In occasional cases of secondary hyperparathyroidism, long term stimulation of the parathyroid glands leads from compensatory to autonomous hyperfunction, and thus, hypercalcemia develops. This clinical entity, named tertiary hyperparathyroidism, is possibly due to the formation of an adenoma in one of the hyperplastic glands. Previous studies have shown that parathyroid adenomas may arise with allelic loss on chromosome 11. We tested for allelic loss at several loci on chromosome 11 in 12 enlarged parathyroid glands from 6 uremic patients and found loss of heterozygosity in 2 of the glands from 2 different patients with higher serum calcium levels (11.3 +/- 0.29 vs. 9.8 +/- 0.28 mg/dL; P < 0.004) and, therefore, ascribable to the so-called tertiary hyperparathyroidism. The 2 glands with allelic loss were significantly greater in mass than those without loss (3.42 +/- 0.37 vs. 1.60 +/- 0.54 g; P < 0.001). These data offer new evidence that autonomous parathyroid proliferation in uremic patients can develop through overgrowth by a monoclonal tumor, presumably with inactivation of a tumor suppressor gene(s) on chromosome 11.

Surgical management of adrenal cortical carcinoma.

The experience with the surgical management of 14 patients with adrenal cortical carcinoma is presented. Four patients were males and 10 females (mean age: 37 years). Seven patients (50%) has proven hormonal activity and 7 (50%) had "non functioning" tumors. The location of carcinoma involved the left adrenal gland in 9 cases, the right in 3 and it was bilateral in 2. The mean diameter of the mass was 10 cm. The most helpful diagnostic tests were shown to be sonography and computed tomography. The surgical procedure was chosen according to the patients condition: this included resection of primary lesion and excision of local lymph nodes and all involved structures. Adjuvant treatment with either mitotane, 5-FU or local irradiation did not result in any benefit with respect to the expected survival. There was a slightly better survival for functioning versus non functioning tumors. Surgery remains the treatment of choice for these tumors. Prognosis is exceedingly poor: only 5 patients (36%) have survived beyond two years after surgery.

Fine needle aspiration cytology of parathyroid adenoma. A review of seven cases.

The value of fine needle aspiration (FNA) cytology in the diagnosis of parathyroid adenomas was demonstrated by a cytohistologic review of seven cases. The cytologic patterns, which were characterized by numerous, mostly isolated epithelial cells and naked nuclei showing anisokaryosis and multiple nucleoli, were consistent with the histologic findings in this neoplasm, which should be considered in the differential (FNA) diagnosis of masses in the neck region. The only diagnostic problem is its differentiation from follicular thyroid neoplasms.

The role of ultrasonography and ultrasound guided biopsy in the management of patients with cold nodules of the thyroid.

The histological diagnoses of surgical specimens from 86 patients with cold nodules of the thyroid (55 goitres, 16 adenomas and 15 malignancies) were compared with the clinical data, ultrasonographic appearances and the results of the fine needle biopsy of each patient to evaluate the role of ultrasonography alone and combined with guided biopsy in distinguishing patients with malignancies from patients without malignancies. The Authors suggest that ultrasonography alone cannot be used for distinguishing malignancies from non-malignancies in cold nodules of the thyroid; the combined use of the ultrasonographic appearances with guided biopsy offers a remarkable diagnostic gain in this field. In the Authors' case material the detection of a simple cyst by ultrasound always excluded the possibility of malignancy.

Thyroxine and triiodothyronine levels in thyroid vein blood and in thyroid tissue of patients with autonomous adenomas.

Thyroxine (T4) and triiodothyronine (T3) concentrations were measured in peripheral and thyroid vein blood and in nodular and extranodular thyroid tissue from twenty-four patients with autonomous thyroid nodules (AFTN); fifteen of these patients showed clinical signs of hyperthyroidism and nine were euthyroid. Thirteen patients with solitary non-functioning thyroid adenomas who were clinically euthyroid, served as controls; samples of thyroid vein blood and normal thyroid tissue being obtained from the contralateral lobe. T4 (189.4 +/- 27.2 nmol/l) and T3 (7.05 +/- 2.03 nmol/l) concentrations were significantly higher in the thyroid vein blood of patients with AFTN compared with controls (T4 = 119 +/- 9.1 nmol/l, P less than 0.05; T3 = 2.3 +/- 0.21 nmol/l, P less than 0.01) whereas peripheral levels in the two groups were similar. The T3 concentrations (10.56 +/- 4.12 nmol/g wet tissue) in autonomously-functioning thyroid nodular tissue were significantly higher than those of extranodular (1.9 +/- 0.62 nmol/g wet tissue, P less than 0.01) and normal thyroid tissue (2.63 +/- 0.43 nmol/g wet tissue, P less than 0.05). The T4 levels were not different in the tissues examined. The concentrations of T4 and T3 in thyroid vein blood did not show any significant correlation with the hormone levels in thyroid tissue.