A Case of Amyloid Goiter Associated with Intrathyroid Parathyroid and Lymphoepithelial Cyst

Abstract

Diffuse enlargement of the thyroid gland accompanied by an interstitial tissue deposition of amyloid is a special entity termed an amyloid goiter. An amyloid goiter is a rare thyroid lesion, which has been described a long time ago. In this report, we add a new classic case of amyloid goiter that differs from other reported cases in its association with intrathyroid parathyroid and lymphoepthelial cyst involved with amyloidosis. The presence of parathyroid tissue inside the thyroid parenchyma and surrounded by amyloid material elicited a diagnostic problem due to suspected medullary carcinoma. Careful histological examination and immunohistochemical staining for parathormone and calcitonin have largely helped in the differential diagnosis. Bilaterality, diffuse, and homogeneous involvement of the thyroid gland, with absence of definite masses, all direct the diagnosis toward amyloid goiter.

Multiple Myeloma Presenting as Massive Amyloid Deposition in a Parathyroid Gland Associated with Amyloid Goiter: A Medullary Thyroid Carcinoma Mimic on Intra-operative Frozen Section

“…However, there are only exceedingly rare clinical (nonautopsy) examples of amyloid deposition in parathyroid glands. Review of the literature yielded four cases (Table 1) [13][14][15]17]. In two of these cases amyloid deposition was noted in parathyroid glands that were removed incidentally in patients who were undergoing thyroidectomy for compression symptoms related to amyloid goiter [13,14].…”

“…Review of the literature yielded four cases (Table 1) [13][14][15]17]. In two of these cases amyloid deposition was noted in parathyroid glands that were removed incidentally in patients who were undergoing thyroidectomy for compression symptoms related to amyloid goiter [13,14]. In one of these cases, the parathyroid was intrathyroidal [14].…”

“…In two of these cases amyloid deposition was noted in parathyroid glands that were removed incidentally in patients who were undergoing thyroidectomy for compression symptoms related to amyloid goiter [13,14]. In one of these cases, the parathyroid was intrathyroidal [14]. Ordonez et al also reported amyloid deposition in an intrathyroidal parathyroid in a patient with hyperparathyroidism for whom an abnormal parathyroid was not localized preoperatively [15].…”

“…The majority of amyloid goiters described in the literature are due to deposition of AA-type amyloid secondary to chronic inflammatory conditions with AL (or primary) amyloidosis being a less common etiology [3][4][5][6][7][8][9]. Of the four examples in the literature of amyloid deposition in parathyroid glands, two were thought to be secondary amyloidosis and in one case an etiology could not be determined consistent with localized amyloidosis [13,14,17]. One report did not mention whether the patient was evaluated for systemic amyloidosis [15].…”

“…Although small amounts of amyloid deposition have been identified with the aid of special stains in a subset of both normal parathyroid glands and from patients with primary hyperparathyroidism, significant and histologically identifiable amyloid deposition is usually associated with systemic amyloidosis and only very rarely comes to clinical attention [10,11]. It is almost always an incidental histologic finding, often at autopsy examination or in a parathyroid removed inadvertently during thyroid surgery [12][13][14][15][16].…”