Water-Clear Cell Adenoma of Parathyroid Gland: A Case Report and Concerns on Differential Diagnosis - Abstract
Primary Water-Clear Cell Adenoma (WCCA) of the parathyroid glands are extremely rare neoplasm, consisting of cells with clear, foamy cytoplasm filled with glycogen, lacking an infiltrative growth pattern and metastases. We report the case of a 58-year-old woman with primary hyperparathyroidism, without a known history of MEN-1 or NF-1, with a tumour posterior to the right thyroid lobe. No evidence of metastasis was reported. The clinical diagnosis was parathyroid adenoma. Following the surgical procedure, we received an encapsulated tumor measuring 4,5 cm in diameter and weighting 12 gr, consisting of water-clear cell cells, without mitoses, atypical features or capsular invasion, at the rim of which normal residual parathyroid tissue was included. The differential diagnosis included a variety of primary and secondary clear-cell tumors of head and neck region, however the morphological and immunohistochemical (strong positivity only for PTH, p27 and bcl-2) assessment drove to the diagnosis of WCCA of the parathyroid gland. After the operation, the levels of PTH in patient’s serum dropped to normal and the post-operative course remained free of symptoms or abnormal laboratory findings. In conclusion, all the clinical and laboratory findings strongly suggested the diagnosis of WCCA of the parathyroid gland, however because of the rarity of this type of tumours, we had to examine this partiular tumour in detail, in order to exclude all the other clear-cell tumours that can appear in this region.