Hypothyroidism following hemithyroidectomy for benign nontoxic thyroid disease.
Hypothyroidism hypothyroidism: see thyroid gland. following hemithyroidectomy for benign nontoxic thyroid disease thyroid disease Thyroid disorder Endocrinology Any benign or malignant condition that affects the structure or function of the thyroid gland. See Anaplastic carcinoma of thyroid, Chronic thyroiditis–Hashimoto's disease, Hyperthyroidism, Hypoparathyroidism, is an underappreciated phenomenon. Up until recently, it was common practice for physicians to place post-hemithyroidectomy patients on thyroid suppression therapy during the immediate postoperative period. That practice began to fall out of favor as a result of two developments: (1) the publication of data that put into question the efficacy of levothyroxine therapy for preventing recurrent disease or thyroid growth and (2) a heightened awareness of the morbidity associated with levothyroxine. We conducted a retrospective chart-review study of 58 patients with benign nontoxic thyroid disease who had undergone hemithyroidectomy from 1994 through 2003 at one institution. Of these 58 patients, 14 (24.1%) had become hypothyroid Hypothyroid
Having too little thyroxin stimulation.
Mentioned in: Goiter
hypothyroid adjective Referring to hypothyroidism, see there after surgery, including 7 who had been so diagnosed 1 month postoperatively and 6 at 2 months. The remaining 44 patients were euthyroid Euthyroid
Having the right amount of thyroxin stimulation.
Mentioned in: Goiter
having a normally functioning thyroid gland. . The mean preoperative pre·op·er·a·tive
Preceding a surgical operation.
preceding an operation.
the preparation of a patient before operation. serum thyroid-stimulating hormone thyroid-stimulating hormone (TSH): see thyrotropin. (TSH TSH thyroid-stimulating hormone; see thyrotropin.
Thyroid-stimulating hormone (TSH) ) levels in the hypothyroid and the euthyroid groups were 2.39 and 1.07 [micro]IU/ml, respectively--a statistically significant difference (p < 0.0001). A tissue diagnosis consistent with chronic inflammation chronic inflammation
Inflammation that may have a rapid or slow onset but is characterized primarily by its persistence and lack of clear resolution; it occurs when the tissues are unable to overcome the effects of the injuring agent. (lymphocytic thyroiditis lymphocytic thyroiditis Atypical subacute thyroiditis, hyperthyroiditis, lymphocytic thyroiditis with spontaneously resolving hyperthyroidism, painless thyroiditis, slient thyroiditis, subacute lymphocytic thyroiditis Endocrinology A condition in which the or Hashimoto's thyroiditis Hashimoto's thyroiditis
The self destruction of the thyroid cells from an autoimmune disorder.
Mentioned in: Hypoparathyroidism
Hashimoto's thyroiditis ) was found in 50.0% of the hypothyroid patients, compared with only 6.8% of the euthyroid patients--again, a significant difference (p < 0.001). No significant difference was seen between the two groups with respect to age, sex, or the weight of the resected gland. We conclude that hypothyroidism after hemithyroidectomy is not an uncommon occurrence. Apparent risk factors include a high mean preoperative serum TSH level and tissue pathology tissue pathology Histopathology Surgical pathology A general term for the evaluation of tissues obtained by biopsy or other surgical
procedure consistent with chronic inflammation. It may be wise to follow patients with these identifiable risk factors more closely during the postoperative period; monitoring should include scheduled serial serum TSH draws.
The development of hypothyroidism following hemithyroidectomy for benign nontoxic thyroid disease is an underappreciated complication. In the past, it was common practice for physicians to place most post-hemithyroidectomy patients on prophylactic thyroid suppression therapy with low-dose levothyroxine. The rationale for this strategy was based on the assumption that the addition of low-dose levothyroxine would prevent recurrence of disease in the remaining thyroid tissue by inhibiting endogenous production of thyroid-stimulating hormone (TSH). A consequence of this practice was that the administration of levothyroxine prevented physicians from recognizing those patients who would have otherwise become hypothyroid after hemithyroidectomy.
In more recent years, physicians stopped administering thyroid suppression therapy during the immediate postoperative period. Instead, the new strategy was to follow these patients clinically for signs of recurrence or growth. The emergence of the new trend was based on two developments: (1) the publication of data that put into question the efficacy of levothyroxine therapy for preventing recurrent disease or thyroid growth and (2) a heightened awareness of the morbidity associated with levothyroxine. (1,2)
One result of thyroid suppression therapy with levothyroxine is subclinical subclinical /sub·clin·i·cal/ (sub-klin´i-k'l) without clinical manifestations.
Not manifesting characteristic clinical symptoms. Used of a disease or condition. thyrotoxicosis thyrotoxicosis /thy·ro·tox·i·co·sis/ (thi?ro-tok?si-ko´sis) a morbid condition due to overactivity of the thyroid gland; see Graves' disease.
n. (subclinical hyperthyroidism subclinical hyperthyroidism A low serum TSH concentration in an asymptomatic person with normal serum thyroid hormone concentrations; SH is more common in older–> age 60 Pts, and detected by measuring TSH Etiology Solitary thyroid adenoma, multinodular ), defined as the presence of a low TSH level with a normal free thyroxine (F[T.sub.4]) level. Some studies have shown an association between this state and various endocrine and cardiac abnormalities. (3-10)
With fewer patients being placed on levothyroxine during the immediate postoperative period, it has become easier to identify those who develop hypothyroidism. Routine thyroid function tests Thyroid Function Tests Definition
Thyroid function tests are blood tests used to evaluate how effectively the thyroid gland is working. These tests include the thyroid-stimulating hormone test (TSH), the thyroxine test (T4), the triiodothyronine test obtained as early as 1 month after surgery may identify those patients with subclinical, as well as overt, hypothyroidism.
We conducted a study to identify certain risk factors that may place a patient at a higher risk for developing hypothyroidism after hemithyroidectomy. These potential risk factors include age, sex, tissue pathology characteristics, the size of the thyroid remnant, a history of neck irradiation, and coexisting thyroid autoimmune disease autoimmune disease, any of a number of abnormal conditions caused when the body produces antibodies to its own substances. In rheumatoid arthritis, a group of antibody molecules called collectively RF, or rheumatoid factor, is complexed to the individual's own gamma .
Patients and methods
After obtaining institutional review board approval, we conducted a retrospective chart review of all patients who had undergone a hemithyroidectomy from 1994 through 2003 at Northwestern Memorial Hospital
A field in anatomical pathology concerned with examination of surgical specimens of tissues removed from living patients for the purpose of diagnosis of disease and guidance in the care of patients. database using the search terms hemithyroidectomy and thyroid lobectomy lobectomy /lo·bec·to·my/ (lo-bek´tah-me) excision of a lobe, as of the lung, brain, or liver.
Excision of a lobe of an organ or a gland. .
Charts were reviewed for information on age, sex, serum TSH levels (both preoperative and postoperative), final surgical pathology results, the weight of the resected gland, postoperative symptoms, a history of neck irradiation, and coexisting thyroid autoimmune disease. The indication for surgery was not used as a criterion for patient eligibility, but we did exclude those patients who had a preoperative diagnosis of malignancy, hyperthyroidism hyperthyroidism: see thyroid gland. , or hypothyroidism. Other exclusion criteria exclusion criteria AIDS Donor exclusion criteria, see there included age less than 18 years or more than 90 years, the administration of postoperative thyroid suppression therapy, previous use of any medication known to alter thyroid hormone Thyroid hormone
Any of the chemical messengers produced by the thyroid gland, including thyrocalcitonin, a polypeptide, and thyroxine and triiodothyronine, which are iodinated thyronines. See Hormone, Thyrocalcitonin, Thyroid gland, Thyroxine or serum TSH level, a completion thyroidectomy Thyroidectomy Definition
Thyroidectomy is a surgical procedure in which all or part of the thyroid gland is removed. The thyroid gland is located in the forward part of the neck (anterior) just under the skin and in front of the Adam's apple. within the previous 2 years, a lack of appropriate laboratory work, and a lack of follow-up.
A total of 58 patients--44 women and 14 men, aged 23 to 75 years (mean 46.5)--met our eligibility requirements. Their tissue specimens were sent for routine pathology and analyzed for the presence of inflammation, the type of nodular nodular
marked with, or resembling, nodules.
see nodular fasciitis (below).
a firm painless nodular swelling, 0. disease, the size of the nodules Nodules
A small mass of tissue in the form of a protuberance or a knot that is solid and can be detected by touch.
Mentioned in: Leprosy , and the surrounding tissue pathology.
An elevated serum TSH level was used as a marker for hypothyroidism. All patients had at least one serum TSH level drawn before surgery and at least one other drawn within 6 weeks after surgery. Serum TSH levels were measured by using the standard serum assay at our institution (range of normal: 0.4 to 4.0 [micro]IU/ml). Patients who were clinically asymptomatic but who had a serum TSH level greater than 4.0 [micro]IU/ml with a normal F[T.sub.4] level were diagnosed as having subclinical hypothyroidism subclinical hypothyroidism An ↑ TSH before or after administration of TRH in the face of normal T3 and T4; SH affects 6-7% of ♀ and 2-3 of ♂, with 5-10% annual rate of progression to overt hypothyroidism in children and . Overt hypothyroidism was diagnosed in those who had an elevated serum TSH level and a low [FT.sub.4] level and in those who had symptoms attributable to hypothyroidism. The scheduling of serum TSH measurements was based on the known half-life of thyroxine ([T.sub.4]), which is 7 days, and the response of serum TSH to changes in the [T.sub.4] level (TSH rises immediately after a drop in [T.sub.4] levels). Although study data vary, it is generally believed that the TSH level should rise in 4 to 5 weeks if the remaining thyroid gland is not producing enough [T.sub.4]. (11)
Data analysis was performed with the unpaired Student's t test for p value calculation, 95% confidence intervals (CIs), means, standard deviations, and percentages.
There were several reasons that only 58 of the 150 patients in our database (38.7%) met our eligibility requirements. First, during the first 5 years of our study's time frame, administration of prophylactic thyroid suppression therapy was routine at our institution. As a result, we had to exclude 50 patients (33.3%), and therefore a good deal of our data was obtained from surgeries performed from 1999 through 2003. Another 27 patients (18.0%) had undergone a completion thyroidectomy within the previous 2 years, and proper follow-up was lacking in 15 others (10.0%).
Of the 58 study patients, 14 (24.1%) had become hypothyroid postoperatively, and the remaining 44 patients (75.9%) were euthyroid.
Demographic characteristics. There were no statistically significant differences between the hypothyroid group and the euthyroid group with respect to age (mean: 47.8 and 46.8 yr, respectively) and sex (distribution: 3 men/11 women and 11 men/33 women, respectively).
Pre-and postoperative TSH levels. The mean preoperative serum TSH level in the 14 patients who had become hypothyroid was 2.39 [micro]IU/ml (range 1.17 to 3.90; 95% CI: 1.53 to 2.94). Their mean postoperative level was 14.88 [micro]IU/ml (range: 4.80 to 70.73; 95% CI: 4.43 to 25.28) (table 1).
A complete thyroid function panel (serum TSH, F[T.sub.4], and [T.sub.4] measurements) was obtained from 8 of the 14 hypothyroid patients. Of these 8 patients, 6 had overt hypothyroidism and 2 had subclinical hypothyroidism. The patients with subclinical hypothyroidism were asymptomatic, but laboratory testing showed a mildly elevated TSH level and a normal F[T.sub.4] level.
Of the 14 hypothyroid patients, 7 were diagnosed as such 1 month postoperatively, 6 at 2 months, and the other at 4 months (table 1). Most of these higher TSH levels ranged between 4.80 and 9.62 [micro]IU/ml (table 1).
In the euthyroid group, the mean preoperative TSH level was 1.07 [micro]IU/ml (range: 0.39 to 2.35; 95% CI: 1.01 to 1.37). The difference in preoperative TSH levels between the hypo- and euthyroid groups was statistically significant (p < 0.0001).
All 44 patients in the euthyroid group had at least one serum TSH level drawn within 6 weeks after surgery. While 34 of them had multiple TSH levels drawn at various times, 10 patients had only one TSH level drawn, and all 10 of these levels had been drawn at either 5 or 6 weeks postoperatively (table 2). Fourteen of the euthyroid patients had TSH levels drawn at 1 and 2 months after surgery; the remaining 20 euthyroid patients had the last of their TSH levels drawn between 4 months and 2-plus years after surgery.
Tissue pathology. Seven of the 14 hypothyroid patients (50.0%) had a tissue diagnosis consistent with inflammation (i.e., chronic lymphocytic thyroiditis chronic lymphocytic thyroiditis Hashimoto's disease, see there and Hashimoto's thyroiditis), compared with only 3 of the 44 euthyroid patients (6.8%). The difference was statistically significant (p < 0.001).
Among the other 7 patients in the hypothyroid group, 4 (28.6%) had a diagnosis of follicular fol·lic·u·lar
1. Relating to, having, or resembling a follicle or follicles.
2. Affecting or growing out of a follicle or follicles. adenoma adenoma: see neoplasm. , 2 (14.3%) had multinodular goiter multinodular goiter
Adenomatous goiter with several colloid nodules. , and 1 (7.1%) had diffuse atrophy and scar tissue scar tissue
Dense, fibrous connective tissue that forms over a healed wound or cut. on the thyroid gland (table 1). The patient with atrophy and scar tissue had undergone treatment with radioactive iodine ([sup.131]I) for multinodular goiter disease 2 years earlier, and she had been euthyroid prior to hemithyroidectomy.
Most of the euthyroid patients had follicular adenoma (table 3). Other pathologies included multinodular goiter, adenomatous adenomatous /ad·e·nom·a·tous/ (ad?e-nom´ah-tus)
1. pertaining to an adenoma.
2. pertaining to nodular hyperplasia of a gland.
1. hyperplasia, and hemorrhagic cysts. Two patients had normal thyroid tissue.
The mean weight of the resected tissue in the hypo-and euthyroid groups was 27.2 and 20.6 grams, respectively. This difference was not statistically significant (p = 0.1662).
Neck irradiation. Only 1 patient--a hypothyroid patient--had a history of neck irradiation.
The usual indication for hemithyroidectomy is the presence of a single dominant thyroid nodule in a patient whose fine-needle aspiration findings are suspicious or indeterminate. Hemithyroidectomy is also performed on patients with unilateral or bilateral thyroid enlargement, toxic or nontoxic nodular thyroid disease, and diffuse or multinodular goiter. Because only one lobe of the thyroid gland is removed, hemithyroidectomy is associated with a lower incidence of postoperative hypocalcemia Hypocalcemia Definition
Hypocalcemia, a low bood calcium level, occurs when the concentration of free calcium ions in the blood falls below 4.0 mg/dL (dL = one tenth of a liter). The normal concentration of free calcium ions in the blood serum is 4.0-6. and recurrent and superior laryngeal nerve superior laryngeal nerve
A branch of the vagus nerve at the inferior ganglion. At the thyroid cartilage, it divides into two branches, the internal, which supplies the mucous membrane of the larynx above the vocal cords; and the external, which injury than is total thyroidectomy. (12) Because the remaining lobe is unharmed, most patients retain enough thyroid function to remain euthyroid. Therefore, hemithyroidectomy is the procedure of choice for patients who likely have benign pathology.
Hypothyroidism. Its advantages notwithstanding, hemithyroidectomy may result in hypothyroidism, and patients should be made aware of this possibility. The risk factors for hypothyroidism have not been extensively studied. During our MEDLINE The online medical database of the U.S. National Library of Medicine (NLM) whose parent is the National Institutes of Health, Bethesda, MD. MEDLINE contains millions of articles from thousands of medical journals and publications. The consumer section of the site (http://medlineplus. literature search, we found that few studies of the incidence and risk factors of hypothyroidism after thyroid lobectomy have been published in the United States; the reported incidence in those studies ranged from 7.4 to 35%. (13,14)
It is standard care to treat overt hypothyroidism with hormone replacement therapy Hormone Replacement Therapy Definition
Hormone replacement therapy (HRT) is the use of synthetic or natural female hormones to make up for the decline or lack of natural hormones produced in a woman's body. , but treatment guidelines are less definitive for subclinical hypothyroidism. The latter has been reported to occur spontaneously in 10% of women older than 60 years. (10) Although patients with subclinical hypothyroidism are clinically asymptomatic, they have an increased risk of developing a major depressive disorder Major depressive disorder
A mood disorder characterized by profound feelings of sadness or despair.
Mentioned in: Conduct Disorder
major depressive disorder or mood disorder, an increased left ventricular hypertrophy left ventricular hypertrophy Cardiology Enlargement of the left ventricle often linked to the prolonged hemodynamic stress of CHF, characterized by myocardial cell hypertrophy, ↑ left ventricular wall thickness, ↓ ventricular compliance, ↑ , and an unfavorable lipid profile. (15-17) Studies have shown that the treatment of subclinical hypothyroidism results in a favorable response in terms of mood affect and low-density lipoprotein levels, and many authors support thyroid hormone replacement therapy in these patients. (18)
Thyrotoxicosis. While prophylactic thyroid suppression therapy was once thought to be devoid of negative health consequences, recent data have shown that subclinical thyrotoxicosis does in fact have some adverse health effects. It has been shown to negatively affect calcium balance and decrease bone mineral density bone mineral density
See bone density.
bone mineral density A measurement of bone mass, expressed as the amount of mineral–in grams divided by the area scanned in cm2. See Bone densitometry. ; increase total cholesterol and low-density lipoprotein levels and decrease high-density lipoprotein levels; and lower the threshold for depression and other psychiatric disorders. (5,6) Subclinical thyrotoxicosis is also associated with a three-fold increase in the risk of atrial fibrillation. (3,4,7) Other cardiac complications include increased heart rate, increased left ventricular mass index, impaired cardiac contractility contractility /con·trac·til·i·ty/ (kon?trak-til´i-te) capacity for becoming shorter in response to a suitable stimulus.
a capacity for becoming short in response to suitable stimulus. , diastolic dysfunction, and the induction of ectopic ectopic /ec·top·ic/ (ek-top´ik)
1. pertaining to ectopia.
2. located away from normal position.
3. arising from an abnormal site or tissue.
adj. atrial atrial /atri·al/ (a´tre-al) pertaining to an atrium.
Of or relating to an atrium.
Having to do with the upper chambers of the heart. beats or arrythmias. (8,9) Those who are specifically at risk for adverse effects are elderly women and patients with a known diagnosis of coronary artery disease coronary artery disease, condition that results when the coronary arteries are narrowed or occluded, most commonly by atherosclerotic deposits of fibrous and fatty tissue. and/or ischemic heart disease Ischemic heart disease
Insufficient blood supply to the heart muscle (myocardium).
Mentioned in: Myocarditis
ischemic heart disease . (10) Therefore, given the lack of substantial evidence supporting the efficacy of thyroid suppression therapy in preventing recurrent thyroid disease, it seems prudent to forgo it as a routine strategy after hemithyroidectomy and to observe patients for the need for thyroid supplementation therapy.
Literature review. Our finding that 24.1% of patients developed hypothyroidism after undergoing hemithyroidectomy for benign thyroid disease is consistent with others reported in the literature. In fact, Buchanan and Lee reported an identical 24.1% incidence in 2001. (19) They found that patients with nodular goiter and elevated thyroid auto-antibody levels were significantly more likely to become hypothyroid following unilateral thyroid lobectomy (p < 0.001). They also found that patients with elevated thyroid autoantibody autoantibody /au·to·an·ti·body/ (-an´ti-bod?e) an antibody formed in response to, and reacting against, an antigenic constituent of one's own tissues.
n. levels had a significantly higher incidence of lymphocytic thyroiditis (p < 0.001). They concluded that an elevated thyroid autoantibody level is an independent risk factor for hypothyroidism. We recognize the role that thyroid autoantibody levels may play in the development of postoperative hypothyroidism, but because ours was a retrospective study, we were limited by the type of data we could analyze, and we therefore did not factor this variable into our analysis.
In 1991, Berglund et al reported that the incidence of hypothyroidism following surgery for benign nontoxic goiter was 7.4%. (13) They found a significant correlation between the incidence of postoperative hypothyroidism and the degree of chronic lymphocytic thyroiditis after unilateral surgery (p = 0.016). A year later, Okamoto et al reported a similar correlation in patients with Graves' disease who underwent subtotal subtotal /sub·to·tal/ (sub-to´t'l) less than, but often almost, complete. thyroidectomy. (20)
Regarding other potential risk factors, we did not find any significant difference between our two groups with respect to age, sex, and the weight of the resected gland. However, we did find that the mean preoperative serum TSH level was significantly higher in the hypothyroid group (2.39 vs. 1.07 [micro]IU/ml; p < 0.0001). That finding supports one reported in 2000 by McHenry and Slusarczyk, who found that the incidence of post-hemithyroidectomy hypothyroidism was 35%. (14) Like us, they found that the incidence of postoperative hypothyroidism significantly correlated with higher preoperative serum TSH levels, and they found no link between postoperative hypothyroidism and age, sex, the presence of inflammation, and the weight of the resected gland. In their study, the mean preoperative serum TSH level was 1.94 [micro]IU/ml in the hypothyroid group and 1.10 [micro]IU/ml in the euthyroid group (p < 0.05).
Our study, like others, has shown that the presence of certain factors may place a patient at a higher risk of developing hypothyroidism following hemithyroidectomy. However, as previously mentioned, we do recognize the limitations of our study, given its retrospective nature. One subject of conjecture is the possibility that some of the hypothyroid patients would have eventually become euthyroid over time as the remaining thyroid tissue compensated for the loss of one lobe. We were unable to determine this because all patients who had an elevated serum TSH level postoperatively were immediately placed on thyroid replacement therapy, regardless of whether they were symptomatic or not. Conversely, we cannot know if the opposite would have occurred. All but 1 of the 14 hypothyroid patients had been so diagnosed within 2 months. However, because serum TSH levels were not drawn from all patients at regular intervals, we cannot know if some of the euthyroid patients who were not followed as often eventually would have become hypothyroid. Our postoperative follow-up period was only 2-plus years. An argument could be made that at least some of the patients in the euthyroid group might have eventually become hypothyroid.
Despite these limitations, we believe that our findings have confirmed the identity of the key risk factors for the development of hypothyroidism during the immediate postoperative period following hemithyroidectomy. We intend to conduct future research in this area by means of a prospective study.
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Tending or serving to suppress.
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1. situated beside the thyroid gland.
2. see under gland.
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Enlargement of the thyroid gland, causing a prominent swelling in the front of the neck. The thyroid normally weighs 0.5 to 0.9 oz (15 to 25 g); however, goitrous thyroid glands can grow to more than 2 lbs (1,000 g). . Eur J Surg 1991; 157:257-60.
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Kristin A. Seiberling, MD; Jose C. Dutra, MD; Sanija Bajaramovic, MD
From the Department of Otolaryngology-Head and Neck Surgery (Dr. Seiberling and Dr. Dutra) and the Department of Endocrinology (Dr. Bajaramovic), Northwestern University Feinberg School of Medicine The Feinberg School of Medicine is one of Northwestern University's 11 schools and colleges. It is a prestigious American medical school located in the Streeterville neighborhood of Chicago, Illinois, situated near Lake Michigan and the Magnificent Mile. , Chicago.
Reprint requests: Kristin A. Seiberling, MD, Department of Otolaryngology--Head and Neck Surgery, Northwestern University Feinberg School of Medicine, 303 E. Chicago Ave., Searle 12-561, Chicago, IL 60611. Phone: (312) 503-8920; fax: (312) 503-1616; e-mail: email@example.com
The information in this article was originally presented at the Triological Society's Combined Otolaryngology Spring Meeting; April 30, 2004; Scottsdale, Ariz.
Table 1. Pathology in the 14 hypothyroid patients TSH level Diagnosis, Preop Postop months Pt. Age ([micro]IU/ml) ([micro]IU/ml) postop * 1 60 1.25 14.20 2 2 73 1.70 9.62 1 3 29 1.23 5.22 2 4 54 3.57 70.73 1 5 58 2.56 4.90 4 6 26 2.21 6.99 2 7 48 2.60 5.96 2 8 61 3.45 16.25 2 9 49 2.42 6.02 1 10 56 1.84 5.86 1 11 32 3.90 4.80 1 12 32 3.10 5.07 2 13 53 2.50 18.25 1 14 38 1.17 34.40 1 Pt. Pathology 1 Multinodular goiter w/degenerative changes 2 Chronic lymphocytic thyroiditis w/follicular adenoma 3 Follicular adenoma 4 Hashimoto's thyroiditis w/colloid nodules 5 Follicular adenoma (benign Hurthle cell adenoma) 6 Diffuse atrophy and scarring of the thyroid gland 7 Diffuse chronic inflammation w/follicular adenoma 8 Chronic lymphocytic thyroiditis w/follicular adenoma 9 Multinodular goiter 10 Chronic inflammation w/follicular adenoma 11 Follicular adenoma 12 Follicular adenoma 13 Hashimoto's thyroiditis w/follicular adenoma 14 Hashimoto's thyroiditis w/adenomatous goiter * The number of months postoperatively that the patient was diagnosed as hypothyroid. Table 2. TSH testing in the 44 euthyroid patients Most recent draw n 5 wk postop 6 6 wk postop 4 2 mo postop 14 4 mo postop 3 5 mo postop 2 6 mo postop 2 7 mo postop 7 1 yr postop 4 >2 yr postop 2 Table 3. Pathologic findings in the 44 euthyroid patients Pathology n (%) Comment Follicular adenoma 26 (59.1) In 2 cases, surrounding tissue contained focal areas of chronic inflammation Multinodular goiter 6 (13.6) Degenerative changes were seen in 2 cases Adenomatous hyperplasia 5 (11.4) Chronic lymphocytic 3 (6.8) thyroiditis Hemorrhagic cyst 2 (4.5) In both cases, large cysts occupied the entire lobe Normal thyroid tissue 2 (4.5)