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E Paloyan

Publications and source records attributed to E Paloyan.

At least 19 recordsLinked to original sources
PubMed1998

Guidelines for the use of radio-iodine, thyroid hormone, and treatment of metastatic disease in patients with differentiated thyroid cancer.

The treatment of metastatic differentiated thyroid carcinoma is currently at a crossroad. The stunning effect of imaging doses of RAI on subsequent treatment doses is being recognized. Alternatives to RAI imaging for diagnostic purposes are being tested; these include ultrasonography for local and cervical nodal remnants/recurrences, Sestamibi and other isotope scanning that do not require the discontinuation of TSH suppression, and the measurement of circulating thyroglobulin that is rapidly becoming the cornerstone of the detection and the treatment follow-up of metastatic carcinoma.

Adult↗
PubMed1997

Hyperparathyroidism associated with a chronic hypothyroid state.

Reports of the coexistence of hyperparathyroidism and thyroid disease have raised the issue of a possible etiologic relationship. The present study tests the hypothesis that chronic elevation of thyroid-stimulating hormone (TSH) is related to the development of hyperparathyroidism. Four groups of 60 female rats were treated as follows: group 1, control; group 2, propylthiouracil (PTU) 0.0025%; group 3, PTU 0.0025% plus thyroxine, 5 microg two times per week; and group 4, only thyroxine. The animals' serum calcium, phosphorus, TSH, thyroxine, and parathyroid hormone (PTH) levels were evaluated at 0, 6, 12, and 18 months. Significant elevation of TSH was sustained throughout the 18 months in groups 2 and 3. The PTH levels were also significantly elevated in both group 2 and group 3 animals (P = 0.02). The histopathologic features of the parathyroids were evaluated at 18 months. In the group 2 (PTU only) animals, which had profound hypothyroid, 44% developed parathyroid adenomas. In the group 3 (PTU plus thyroxine) animals, who had mildly elevated TSH levels, 53% developed parathyroid adenomas. These findings are consistent with the hypothesis that prolonged TSH stimulation may lead to hyperparathyroidism in the rat model.

Adenoma↗
PubMed1996

Phosphate administration increases both size and number of parathyroid cells in adult rats.

Phosphate administration increases both parathyroid hormone (PTH) secretion and parathyroid size in rats, but the relative contribution of hypertrophy and hyperplasia is unknown. Accordingly, we reexamined parathyroid histology in a previously published experiment [6], quantitatively rather than qualitatively. Ninety female Long-Evans rats were divided into six groups; three were given a normal diet, and three a high phosphate diet (Ca/P 1:7). One group from each arm was killed after 1, 2, and 3 months. Quantitative microscopy was performed on the parathyroid section with the largest area from each animal, without knowledge of its experimental status. Total gland area and total number of cell profiles did not change significantly in the control rats, but increased progressively in the phosphate-loaded rats. At 3 months, the difference was +194% for gland area and+151% for profile number (P < 0.0001), much more than could be accounted for by suppression of apoptosis. Mean nuclear profile area and mean cell profile area (including associated connective tissue as well as cytoplasm) were both significantly increased at 1 month (P < 0.0001). The differences persisted, but their magnitudes (about +16%) did not change further. This time course was consistent with the morphologic expression of increased PTH secretory activity. We conclude that phosphate administration to adult rats increases both size and number of parathyroid cells, the latter due to increased cell proliferation. Phosphate-stimulated parathyroid growth could be due to either hypocalcemia or decreased calcitriol production; increased cell division may also be linked to increased hormone secretion, regardless of its cause. The relative importance of these different mechanisms remains to be determined.

Animals↗
PubMed1995

Nodular disease during pregnancy.

The incidence of autoimmune disease of the thyroid approaches 10% in women. This autoimmune state, which predisposes to the development of thyroid neoplasia, especially in patients with subclinical hypothyroidism, combined with tumor growth and immunologic factors that occur in the pregnant state, account for the significant incidence of nodular thyroid disease in pregnancy. Thyroid carcinoma of follicular cell origin in a young woman can generally be expected to pursue a slow course with ample time for preoperative preparation and operative treatment. However, the pregnant state should be considered an exception and thyroid nodular disease with suspicious aspiration cytologic features should be managed with a certain degree of urgency. In an excellent article on the subject of pregnancy as a predisposing factor in thyroid neoplasia, Rosen and Walfish present a series of 30 patients with thyroid neoplasia arising during pregnancy. The incidence of thyroid carcinoma was 43% and the incidence of adenoma 37%, for an 80% overall incidence of neoplasia. Furthermore, during the course of the pregnancy, 20% of the patients showed marked increase in nodular growth, including a 26-year-old primiparous woman who developed a small nodule in the first trimester which proved to be cellular on needle aspiration biopsy. In spite of thyroid hormone treatment, the nodule grew markedly in the last trimester. At postpartum operation, the patient was found to have a papillary carcinoma with extensive unilateral neck and mediastinal node disease, which was clinically occult. These authors stress the importance of the operative treatment of thyroid neoplasia of pregnancy, either in the second trimester or immediately after delivery. We agree.

Adult↗
PubMed1995

Congenital thyroid hemiagenesis.

Failure of embryologic development of a lobe of the thyroid gland is a rare anomaly. In order to characterize this unusual entity, we report our experience in seven patients with thyroid hemiagenesis involving the left lobe in five and the right lobe in two patients. The diagnosis was made as a result of evaluation and treatment of a thyroid nodule (4), diffuse thyroid enlargement with thyrotoxicosis (2), and a simple goiter in a patient with a prior history of radiation treatment for facial acne. In five patients thyroid scintigraphy demonstrated unilateral absence of function, four of whom had an ultrasound exam of the neck that revealed a corresponding absence of thyroid tissue. In one patient the diagnosis was made incidentally on a screening ultrasound exam of the neck. Thyroid hemiagenesis was unsuspected preoperatively in one patient with Graves' disease because of marked hyperplasia of a single thyroid lobe and isthmus. Thyroid hemiagenesis was confirmed in four patients who underwent thyroidectomy. The presence of a thyroid isthmus was established in six patients. Postoperatively, all patients were treated with thyroid hormone. Associated thyroid pathology included adenoma (1), follicular carcinoma (1), colloid nodule (2), Graves' disease (2), and a simple goiter (1). In conclusion, the diagnosis of thyroid hemiagenesis should be considered in any patient with unilateral absence of function on thyroid scintigraphy and confirmed by ultrasonography. Recognition of this rare congenital anomaly is important to avoid unnecessary contralateral neck exploration with its potential morbidity and to insure that all patients receive careful follow-up and appropriate thyroid hormone therapy when necessary.

Adenocarcinoma, Follicular↗
PubMed1994

Parathyroid autotransplantation in patients undergoing a total thyroidectomy: a review of 261 patients.

Parathyroid autotransplantation was first described in 1907 by Halsted. However, this simple and effective method of preserving parathyroid function has been used with increasing frequency only during the past 25 years. Beginning in the late 1960s, our group has transplanted normal parathyroid tissue into the ipsilateral sternocleidomastoid muscle whenever these glands could not be preserved in situ with adequate blood supply. In addition, if the blood supply of all four parathyroid glands appeared compromised, cryopreservation of parathyroid tissue was performed in case the autotransplanted tissue did not function after surgery. Since 1970, 393 patients underwent a total thyroidectomy. Parathyroid glands that could not be saved in situ were biopsied to confirm their identity by frozen section and then autotransplanted. Of the 393 patients who underwent a total thyroidectomy, 261 patients required transplantation of one or more glands. Among those 261 patients who underwent selective parathyroid autotransplantation, 33 (13%) required temporary calcium and vitamin D supplementation. Of these 33 patients, 2 (less than 1%) had permanent hypoparathyroidism and are receiving long-term vitamin D therapy.

Adolescent↗
PubMed1993

Hyperparathyroidism induced by hypothyroidism.

The coexistence of hyperparathyroidism and thyroid tumors and/or chronic thyroiditis has raised the possibility of an etiologic relationship. The present study was designed to test the hypothesis that the chronic elevation of thyroid-stimulating hormone (TSH) is related to the development of hyperparathyroidism. Three groups of 24 rats each were treated for 12 weeks as follows: group 1 received propylthiouracil (PTU) in their deionized water; group 2 received PTU and thyroid hormone to suppress TSH and to serve as a control group for possible direct effects of PTU; and group 3 was not treated at all and served as another control group. At 12 weeks, 95% of group 1 rats (PTU only) showed hyperplasia of the parathyroids with a 30% mean increase in circulating parathormone.

Administration, Oral↗
PubMed1993

Primary papillary thyroid carcinoma presenting as cervical lymphadenopathy: the operative approach to the "lateral aberrant thyroid".

In contrast to a few follicles arranged in a wedge-shaped segment at the periphery of a lymph node, a significant amount of thyroid tissue in a cervical lymph node is considered evidence of metastatic thyroid carcinoma. In a consecutive series of 243 patients with papillary carcinomas, 52 presented with lateral cervical masses that proved to be lymph nodes with metastatic thyroid carcinoma, in the absence of readily palpable thyroid nodularity. The metastatic disease was demonstrated by excisional biopsy in 40 patients and fine needle aspiration cytology in 12 patients. Thirty-two (of the 52) underwent further diagnostic work-up, consisting of radionuclide scintigraphy and ultrasonography, with the demonstration of abnormalities consistent with a thyroid neoplasm in 75 per cent (24/32) of these patients. The remaining 20 patients had no additional studies except for chemical thyroid function evaluation. The operative treatment in all 52 patients was total thyroidectomy and unilateral or bilateral modified neck dissections, when extensive cervical adenopathy was encountered. Papillary thyroid carcinoma, ranging in size from 2 to 14 mm, was found in the lobe ipsilateral to the presenting cervical node metastasis, in all specimens. In addition, contralateral cervical lymph node metastases were found in five (10%) of these patients, with no evidence of thyroid carcinoma in the corresponding thyroid lobe. With a mean follow-up period of 9 years, all patients are alive with no evidence of recurrence.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Recurrent hyperparathyroidism due to parathyroid autografts: incidence, presentation, and management.

Recurrent hyperparathyroidism (HPT) occurs in a small percentage of patients undergoing parathyroidectomy for primary HPT and is usually due to inadequate excision of hyperfunctioning parathyroid tissue in the neck, a missed ectopic and hyperplastic parathyroid, or, less commonly, parathyroid carcinoma and parathyroid autografts. In order to determine the incidence, clinical characteristics, and outcome of patients with recurrent HPT due to parathyroid autografts, we reviewed our experience with 604 consecutive patients operated on for primary HPT between 1965 and 1989. One hundred of these patients received parathyroid autografts consisting of portions of one or more parathyroid glands. Three patients with autografts, placed in the sternocleidomastoid muscle, developed recurrent HPT due to their autografts for an incidence of 3 per cent. Recurrent disease was diagnosed between 62 and 113 months with an average of 89 months. The autotransplants in all three of these patients were from hyperplastic or adenomatous parathyroid tissue. Two patients had a history of neck irradiation. Preoperative thallium scans accurately localized the hyperfunctioning parathyroid tissue in all three patients. At operation, the hyperfunctioning autografts had grown into a discrete mass with a single vascular pedicle and were resected. Histologic examination disclosed either hyperplastic or adenomatous tissue, and corresponded to the histology and location of the original tissue transplanted in each case. Follow-up ranges from 12 to 67 months, with an average of 48 months. All patients remain cured and none require oral calcium supplementation. We conclude that graft-dependent recurrent HPT is due to the autotransplantation of hyperplastic or adenomatous parathyroid tissue and that thallium scanning is instrumental for diagnosis and localization.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Necessity and safety of completion thyroidectomy for differentiated thyroid carcinoma.

BACKGROUND: The diagnosis of thyroid carcinoma during the course of lobectomy for a dominant nodule occasionally cannot be rendered on the basis of frozen section. Once the diagnosis of carcinoma is made, the question of completion thyroidectomy arises. The decision to perform completion thyroidectomy and the timing, safety, and efficacy of this procedure are reviewed. METHODS: During the past 25 years (1965 to 1990), we operated on 351 consecutive patients with thyroid carcinoma. One hundred of these patients (84 women and 16 men) were initially treated by unilateral thyroid lobectomy for the previously stated reasons. Histopathologic examination of the permanent sections of the initial thyroid lobectomy specimen demonstrated papillary carcinoma in 70 patients and follicular carcinoma in 30 patients. Within a few months, a completion thyroidectomy was performed. RESULTS: The completion thyroidectomy specimen contained papillary carcinoma in 33 (47%) of the 70 patients with papillary carcinoma and 10 (33%) of the 30 patients with follicular carcinoma. Overall, 43 of these 100 patients harbored thyroid carcinoma in the contralateral lobe. Complications of completion thyroidectomy were transient recurrent nerve paresis in two patients and temporary hypoparathyroidism in three patients, requiring calcium and vitamin D therapy for a few months. CONCLUSIONS: Although the significance and treatment of papillary carcinoma are debated on the basis of size and grade of the primary lesion and age and sex of the patients, once the diagnosis is made in one lobe we believe that a completion thyroidectomy should be considered, not only for papillary carcinomas but also for follicular carcinomas because 47% (papillary) to 33% (follicular) of these patients will harbor the neoplasm in the contralateral lobe.

Carcinoma↗
PubMed1991

High phosphate diet-induced primary hyperparathyroidism: an animal model.

Primary hyperparathyroidism (PHPT) is increasing in incidence and detection, primarily because of the aging of our population and the widespread use of automated serum calcium determination. As a result, a substantial number of "early" cases or "biochemical" PHPT are being detected. The indications for parathyroidectomy in such early cases of PHPT are currently under debate, primarily because of economic issues. These factors underscore the importance of research into the basic mechanisms and natural history of PHPT. We investigated an animal model of diet-induced PHPT that retains two crucial aspects of PHPT: elevation of endogenously produced parathyroid hormone (PTH), accompanied by gross and microscopic changes in the native parathyroid glands. Female Long-Evans rats were divided into six groups of 15 each and fed a control diet (Ca/P of 1:2) or a high-phosphate diet (Ca/P of 1:7) for 1-, 2-, or 3-month intervals. Compared with the control animals, serum PTH levels were elevated at all three time intervals in the experimental group, whereas serum calcium levels were decreased at all time intervals. Serum creatine levels were also elevated at all time intervals, whereas serum phosphorus levels did not change. Parathyroid histopathologic studies demonstrated no change at 1 month, whereas nine of 15 experimental animals showed mild hyperplasia at 2 months and 13 of 14 showed mild to moderate hyperplasia with gland enlargement at 3 months compared with control animals. Histopathologic examination of the kidneys showed no change at 1 month but focal parenchymal inflammation with calcium deposition at 2 and 3 months in the experimental groups. In conclusion, the high-phosphate diet successfully induced the earliest changes of PHPT: elevated PTH levels and parathyroid hyperplasia. However, because renal function was mildly compromised early on, some element of early secondary (renal) hyperparathyroidism may have supervened quickly. Because this model is simple, it may be useful to investigate this complex syndrome further, as well as its natural history and the complications it produces in other organs such as the kidneys.

Animals↗
PubMed1991

Anaplastic thyroid carcinoma: risk factors and outcome.

Anaplastic thyroid carcinoma, in contrast to well-differentiated thyroid carcinoma, has a dismal prognosis, and little progress has been made in improving survival for this disease. We reviewed our experience during a 23-year period to identify risk factors and possible methods to improve outcome. Between 1966 and 1989, 340 patients with thyroid carcinoma underwent operation. Of these, 17 (5%) were undergoing operative treatment of anaplastic or undifferentiated thyroid carcinoma. The female/male ratio was 3.5:1, and mean age at presentation was 63 years. The most common presenting symptoms included neck mass, voice change, or dysphagia. Unusual presentations included symptomatic bradycardia from compression of the vagus nerve and superior vena cava syndrome. Four patients had a history of well-differentiated thyroid carcinoma. Nine patients had been diagnosed or treated in the past for "goiter" or a neck mass, and four patients had concurrent differentiated thyroid carcinoma associated with the anaplastic tumor. Thus 13 (76%) of 17 patients had a previous thyroid disorder, benign or differentiated malignant, and eight (47%) of 17 patients had previous or concurrent differentiated thyroid carcinoma. At the time of presentation, six patients had unilateral true vocal cord paralysis. At operation, 14 patients had local extension of the tumor and four required tracheostomy. Only five of 12 patients showed response to postoperative radiation therapy. Overall median survival was 12 months, and 13 (76%) of 17 patients died. The two patients alive longer than 12 months had only small foci of anaplastic carcinoma in association with well-differentiated carcinoma. Anaplastic thyroid carcinoma is a locally and systemically aggressive disease, with long-term survival seen only in those with well-localized anaplastic tumor. The major risk factor in this series is a history of previous benign or malignant thyroid disease. Because of this, a more aggressive approach to thyroid masses may be warranted. Long-standing goiters or benign nodules should be followed carefully and considered for resection if they grow or do not respond to medical therapy, and total thyroidectomy for malignant disease may obviate the subsequent development of anaplastic carcinoma. This method of early diagnosis and resection of abnormal thyroid tissue seems to be the only method currently available to improve the nearly uniform fatality of this disease.

Adult↗
PubMed1991

Thyroid carcinoma and hyperparathyroidism after radiation therapy for adolescent acne vulgaris.

Thyroid and parathyroid disease after head and neck irradiation in infancy and childhood is well known. Patients irradiated for facial acne were older and received a comparatively lower dose of radiation. These mitigating factors suggest a decreased incidence of thyroid and parathyroid disease in these patients. Over the past 28 years (1961 through 1989), 347 consecutive patients were operated on for radiation-associated thyroid and/or parathyroid disease. One hundred and ten patients in this group were irradiated for treatment for adolescent facial acne vulgaris. The interval between radiation exposure and thyroidectomy ranged from 7 to 57 years (mean, 30 years). The overall incidence of thyroid carcinoma was 31% (34 of 110 patients). Regional metastases in 10 patients (29%) were treated with modified radical neck dissection. Hyperparathyroidism, detected in 31% (34 of 110 patients) of this population, was treated with sub-total parathyroidectomy in all cases. The association of thyroid carcinoma and hyperparathyroidism after adolescent radiation exposure for acne vulgaris appears to be more than coincidental. The incidence of thyroid and parathyroid disease may be independent of the timing and dosage of radiation treatment. These thyroid and parathyroid tumors may develop decades after the initial radiation exposure.

Acne Vulgaris↗
PubMed1990

The relationship between Hashimoto's thyroiditis, thyroid neoplasia, and primary hyperparathyroidism.

The relationship between Hashimoto's thyroiditis and follicular cell carcinoma of the thyroid remains controversial. Hashimoto's thyroiditis is regarded by some as a premalignant lesion for which thyroidectomy is definitely indicated. In contrast, other investigators have found no increased evidence of thyroid carcinoma in patients with this disease. As a result, the management of thyroid nodules in patients with Hashimoto's thyroiditis remains highly individualized. A program for the management of patients with chronic Hashimoto's thyroiditis with co-existing neoplasia or primary hyperparathyroidism is outlined.

Adenocarcinoma↗
PubMed1990

Follicular cell predominance in the cytologic examination of dominant thyroid nodules indicates a sixty percent incidence of neoplasia.

The interpretation of aspiration cytologic smears that contain a predominance of follicular components often presents a dilemma to the clinician who is treating a patient who has a dominant thyroid nodule, especially when thyroid-stimulating hormone suppression does not produce any significant involution of the dominant nodule. We reviewed a consecutive series of 555 fine-needle aspiration cytologic examinations of dominant thyroid nodules. All specimens that contained colloid or follicular cells mixed with lymphocytes or Hürthle cells were excluded from this review. Additionally, nine aspirates contained degenerated follicular cells with insufficient material for cytologic diagnosis. The remaining 76 specimens contained a predominance of follicular cells: 27 specimens were interpreted as containing "normal" follicular cells, and the remaining 49 specimens were read as "atypical" follicular cells. Histopathologic examination of the resected specimens indicated a 60% incidence of neoplasia (30% carcinoma, 30% adenoma) in which the aspiration cytologic study was interpreted as "normal" follicular cells. On the other hand, a 63% incidence of neoplasia (27% carcinoma, 36% adenoma) occurred in which the cytologic study was read as "atypical." In conclusion, aspirates showing a predominance of follicular cells, whether "normal" or "atypical" indicate a 60% incidence of neoplasia in dominant thyroid nodules that do not decrease significantly in size with thyroid-stimulating hormone suppression.

Adenocarcinoma↗
PubMed1990

Long-term results of adrenal autotransplantation in Cushing's disease.

Many advances have been made in the diagnosis and treatment of patients with Cushing's disease. Currently, partial or total transsphenoidal resection of the pituitary gland is the surgical approach favored by many authorities, with cure rates of 80% to 90% reported for selected patients. However, long-term follow-up is still needed for this treatment modality, and recurrence rates of up to 50% have been reported. In addition, less favorable results are seen with this approach when there is recurrence after initial transsphenoidal surgery or when there is not a single microadenoma responsible for the disease of the pituitary gland. We report a series of 14 patients who were treated with bilateral adrenalectomy and autotransplantation. Follow-up is 4 to 14 years. Four patients show iodocholesterol uptake at the site of autotransplantation. Of these, three patients have been weaned from cortisone for 12, 10, and 2 years. The fourth patient, after being weaned from all medications, underwent partial resection of a hyperfunctioning autotransplant and currently, 7 years after the original operation, is being weaned from cortisone. A fifth patient was weaned to a reduced dose of cortisone for 8.5 years, but the dose was recently increased. There is no evidence of Nelson's syndrome in any of these patients with clinical evidence of functioning autotransplants. We believe that bilateral adrenalectomy with autotransplantation still plays an important role in the long-term management of selected cases of Cushing's disease and that autotransplantation, when successful, results in few complications and allows long-term freedom from exogenous steroid medication.

Adolescent↗
PubMed1990

Parathyroid autotransplantation in total thyroidectomy.

Although parathyroid autotransplantation during the course of thyroidectomy was first described by Halsted in 1907, it is only during the past 20 years that this simple and effective method of preserving parathyroid function is being used by an increasing number of surgeons. Our group has autotransplanted normal parathyroids since 1965, whenever these glands could not be preserved in situ with adequate blood supply. With increasing experience, we find it much simpler to autotransplant parathyroid glands attached to the thyroid, than to dissect their precarious blood supply, hoping they will survive postoperative edema and fibrosis. Furthermore, it is our impression that in operations for thyroid carcinoma, attempts to preserve the blood supply to the parathyroids may compromise the completeness of the thyroidectomy or of the dissection of cervical nodes in the tracheoesophageal groove. In a review of our experience during the past four years (January 1, 1984 to December 31, 1988), 87 patients underwent total thyroidectomy. Parathyroid glands that could not be saved in situ were biopsied to confirm their identity by frozen section and autotransplanted in the ipsilateral sternocleidomastoid muscle. Among the 87 patients undergoing total thyroidectomy, 34 required no autotransplantation, whereas 52 had one to three glands autotransplanted, and one had four glands autotransplanted. Postoperatively, 23 patients (26 percent) developed hypocalcemia, whereas 18 required CaCO3 and five required vitamin D in addition. All patients (98%) except two had normal parathyroid function at four-month follow-up and thereafter, as judged by serum calcium, phosphorus and parathormone, when indicated.

Adult↗