An Unusual Ectopic Location of a Parathyroid Carcinoma Arising within the Thyroid Gland

Abstract

Introduction: Parathyroid carcinomas are very rare tumors and may arise in the normally located or ectopic gland. The latter present certain diagnostic difficulties, and there are no specific guidelines on their management. We present a case of parathyroid carcinoma arising within an ectopically located intrathyroid gland and discuss the diagnosis, management, and difficulties encountered. Furthermore, we review all six previously reported cases of this rare event and demonstrate the patterns in presentation, as well as the differences in management.

Pierwotna nadczynność przytarczyc w przebiegu raka przytarczyc — wyzwanie diagnostyczne i terapeutyczne

“…The radioisotope is taken up by the diseased parathyroid rapidly and retained longer [2]. However, some patients with PC may have negative scans [39].…”

“…It has been reported that sensitivity for FNA in diagnosing malignancy is about 50% [2]. In 1973 Schantz and Castleman proposed the criteria that may be helpful to diagnose cancer.…”

“…Surgery still remains the only curative treatment, even in metastatic disease [2,3,5]. En bloc resection of the tumour with ipsilateral thyroid lobectomy, adjacent musculature, paratracheal lymphatic tissue (level VI), and sometimes thymus is often recommended for parathyroid carcinoma; however, it is possible only in 10 to 15% of cases because of delay in diagnosis and advanced disease [4,6,14].…”

“…Parathyroid carcinoma (PC) was first described by De Quervain in 1904 [1,2]. It is a rare endocrine malignancy [3][4][5][6], which originates in the parenchymatous cells of the parathyroid glands [1].…”

“…The histological features of PC may initially be also non-specific [3,4]. Moreover, parathyroid gland could be located in ectopic sites such as the mediastinum, the base of the skull, and within the thyroid gland, and when it occurs the diagnostic difficulty increases significantly [2,13]. It is known…”