Pathologic features of polycystic thyroid disease: Comparison with benign nodular goiter

Abstract

Polycystic thyroid disease (PCTD) is characterized by multiple thyroid cysts detected by ultrasonography, the absence of thyroid autoantibodies, and susceptibility to the development of hypothyroidism due to a high iodine intake [1]. We previously reported that hypothyroidism induced by PCTD accounted for about 7% of all causes of hypothyroidism in a region with a high iodine intake [2]. We speculated that the development of hypothyroidism was due to a decreased volume of normal thyroid hormone-producing tissue because of multiple cysts in PCTD. From the previously published images of ultrasonography, PCTD may have been classified as multinodular goiter thus far. We have to obtain histopathological information on PCTD in order to clarify whether it is different from multinodular goiter. We retrospectively identified three patients with PCTD who underwent thyroidectomy because of Abstract. Polycystic thyroid disease (PCTD) is characterized by multiple thyroid cysts detected by ultrasonography, the absence of thyroid autoantibodies, and susceptibility to the development of hypothyroidism due to a high iodine intake. It is necessary to obtain histopathological information on PCTD in order to clarify the cause of hypothyroidism. We retrospectively reviewed three patients with PCTD and small papillary thyroid cancer who underwent thyroidectomy. We observed the thyroid tissues pathologically in areas with and without multiple cysts, and compared them with those of multinodular goiter with cysts. In the patients with PCTD, there were multiple enlarged follicles that resembled enlarged normal follicles and differed from those found in multinodular goiter in terms of their shape. Huge follicles corresponded to the cysts that were detected by ultrasonography. Each follicle contained colloid. Follicular cells in enlarged follicles comprised low cuboidal epithelium that appeared normal. These findings were common in the 3 patients with PCTD. In Conclusion the PCTD patients had multiple enlarged follicles that seemed to decrease the total number of follicular cells, and may be a cause of hypothyroidism. We believe that PCTD is a new entity of thyroid disease based on the pathological findings.Key words: Hypothyroidism, Thyroid cyst, Polycystic thyroid diseases, Pathology papillary thyroid carcinoma, and were able to obtain the PCTD tissues. We present the pathologic findings of PCTD in these patients and compare them with those of multinodular goiter with cysts in this report. subjects and MethodsThe subjects were three PCTD patients who underwent thyroidectomy because of papillary thyroid carcinoma. Since the carcinomas in these patients were small, we were able to observe the non-carcinomatous thyroid tissues. As control cases, we collected seven cases with multinodular goiter macroscopically containing multiple cystic lesions, which were resected from 2007 to 2010 in our hospital. Serum thyroid hormone levels were normal in all control cases. We observed the tissues of cystic lesions and normal-looking areas in both group...

Polycystic Thyroid Disease in Pediatric Patients

“…2 Some authors postulate that cyst formation in polycystic thyroid disease replaces the gland, leading to a lessening in the number of follicular cells, which may result in thyroid deficiency even in the context of high iodine diets and is also similar to that in patients who have undergone partial thyroidectomy. 3,5 Our second patient presented with subclinical hypothyroidism, possibly due to multiple etiologies. For example, lithium carbonate is a well-known cause of induced hypothyroidism.…”

“…Hypothyroidism related to polycystic thyroid disease has been described in areas with high iodine intake 1 , 2 . Sonographic findings of multiple small thin‐walled simple thyroid cysts in the absence of thyroid autoantibodies suggest the diagnosis of polycystic thyroid disease 3 . Usually, this entity has been misdiagnosed as a multinodular goiter or as a Hashimoto thyroiditis without thyroid autoantibodies.…”

Diagnostic Significance of Subclinical Hypothyroidism in Health Check-ups

“…Concerns about SHT have been increasing in recent years 3,4) . The thyroid state of SHT is very frequently encountered in clinical practice due to such reasons as previous therapy for hyperthyroidism with antithyroid drugs, radioiodine therapy or surgery, post-destructive thyroiditis, patients on L-T4 replacement therapy for hypothyroidism, postpartum autoimmune thyroid syndrome 5) , painless thyroiditis, recovery from nonthyroidal illness, central hypothyroidism, thyroid hormone-resistant syndrome, polycystic thyroid disease 6) and adrenal insufficiency.…”