Multiple Branchial Cleft-Like Cysts in a Female Patient with Hashimoto's Thyroiditis.

Abstract

Abstract.We report a case of branchial cleft-like cysts (intrathyroidal lymphoepithelial cysts) associated with Hashimoto's thyroiditis.Palpation did not detect any nodules. Multiple cystic lesions were detected in the lateral side of the thyroid bilateral lobes by imagings of an I-123 scintigram, T1-201 scintigram, sonography, and computerized tomography.Sonography displayed multiple cysts with strong echogenic spots in the cystic fluid. Repeated fine needle aspiration biopsies of the cysts consistently revealed only normal lymphocytes.Although these lesions could not be given diagnosis, subtotal thyroidectomy leaving the intact isthmus was performed.Microscopic findings revealed multiple branchial cleft-like cysts lined by flattened epithelial cells. Surrounding the epithelial lining were dense lymphoid follicles with large, reactive germinal centers. The remaining thyroid parenchyma showed Hashimoto's thyroiditis.Multiple branchial cleft-like cysts should be considered when sonographic examination reveals multiple cysts in the lateral side of the bilateral lobes, and fine needle aspiration biopsy displays only normal lymphocytes.To our knowledge, this is the first case of branchial cleft-like cysts associated with Hashimoto's thyroiditis reported in Japan.

Branchial cleft‐like cysts in Hashimoto's thyroiditis: A case report and literature review

“…The other process is squamous metaplasia of a cystic lesion which developed as a result of degeneration in a nodular goiter or a neoplasm. 5,11 In our case, the latter is suggested. This is because the cysts are multiple, with the background of fibrosis, and some SCN-like aggregations seem to be in the state of transition from thyroid follicles to squamous metaplasia.…”

“…The exact pathogenesis of intrathyroidal branchial cleft‐like cysts remains unclear, but there are probably two different processes for its development; the first is that branchial remnants such as SCNs cystically degenerate due to chronic inflammation. The other process is squamous metaplasia of a cystic lesion which developed as a result of degeneration in a nodular goiter or a neoplasm . In our case, the latter is suggested.…”

“…Even in recent reports, the authors claim that more reports and further investigation are necessary to determine the origin and the mechanism of formation of multiple branchial cleft‐like cysts . In this paper, we reported our new case of this interesting lesion and updated the current information regarding branchial cleft‐like cysts that appears in the literature.…”

“…That is, most cystic lesions of the thyroid develop as a result of degeneration in a nodular goiter or a neoplasm, and these cysts are usually lined by squamous epithelia. 5,11 In most immunohistochemical studies, SCN shows positive staining for high and low molecular weight cytokeratins and CEA, and negative staining for thyroglobulin. [12][13][14][15] However, CEA staining of the epithelial cells of the thyroid branchial cleft-like cysts are positive in some cases and negative in the others, 5 which indicates that there are different pathogeneses for the cysts.…”

“…Cysts are lined predominantly by attenuated or stratified squamous epithelium and focally by columnar epithelium, and dense lymphoid tissue having conspicuous follicle formation present beneath the lining epithelium. The histogenesis of branchial cleft‐like cysts is assumed to be intrathyroidal branchial remnants such as solid cell nests (SCNs) and it is also thought that the occurrence of these lesions are strongly associated with chronic thyroiditis such as Hashimoto's thyroiditis, but this is still controversial. Although similar epithelial‐lined cysts have been reported in the spleen, its pathophysiology is also uncertain while there are several hypotheses proposed …”