Parathyroid Benign  

Case 1 Female in 80’s. Primary hyperparathyroidism secondary to adenoma. Hypercalcaemia, urgent neck exploration, 1.4g parathyroid up to 45mm in size, with 40mm blood containing cyst. This lesion was a benign parathyroid adenoma that was part cystic with some degenerative features but without criteria for malignancy.

Case 2 Male in 60’s, mass located high in carotid sheath, for 12 years weighing 48g. Parathyroid adenoma with clear cell (water clear) change, see higher power views here and here.  Other possible diagnoses were paraganglioma and possible parathyroid carcinoma, or metastatic renal cell carcinoma. The preferred diagnosis was parathyroid adenoma with water clear change 

Case 3 Female late 70’s parathyroid excision. An oncocytic parathyroid adenoma, This lesion while quite atypical in its cytology did not show malignant features. 

Case 4 Female early 30’s parathyroidectomy 3 years ago, now continuing hyperparathyroidism, tissue in scar and mid trachea level VI. Tissue taken for frozen section. Benign parathyroid implants/ parathyromatosis , see also views here of nodules of parathyroid tissue embedded in skeletal muscle  . Parathyroid carcinoma is in the differential diagnosis. This case was originally diagnosed as a parathyroid carcinoma and a radical neck dissection performed. It was only after there was a recurrence in the thorax on mediastinoscopy that the final diagnosis of benign implantation due to secondary hyperparathyroidism was made. 

Case 5 Female, mid 70’s, primary hyperparathyroidism, mediastinal parathyroid, thoracotomy, specimen 26g, 70x42x23mm, solid with central cyst up to 15mm. Solid area circulated.  This was diagnosed as a benign parathyroid adenoma  see also here provided the other glands were confirmed to be of normal size. Exceptionally large and ectopically located in the mediastinum but a 70mm mediastinal gland has been previously reported – Ann Ital Chir 2009 Jan-Feb 80(1):55-9. Although this lesion has fat within it there is not enough fat for a diagnosis of lipoadenoma. The Mayo Clinic apparently requires >50% fat for a lipoadenoma; others have not quantified it. Lipoadenomas can contain other elements similar lto a hamartoma