Table 3.

Seven cases of tumor-to-tumor metastasis involving the parathyroid gland [1, 6, 7, 9, 12, 15, 21]

Article	Primary malignancy	Primary tumor site	Secondary tumor
Woolner et al. [9]	Carcinoma	Breast	Parathyroid adenoma
Margolis et al. [12]	Poorly differentiated adenocarcinoma	Breast	Parathyroid adenoma
Schwartz et al. [15]	Clear cell carcinoma	Kidney	Parathyroid adenoma
Inoshita et al. [1]	Melanoma	Hard palate	Parathyroid adenoma
Benisovich et al. [21]	Adenocarcinoma	Lung	Parathyroid adenoma
Fulciniti et al. [6]	Infiltrating ductal carcinoma	Breast	Parathyroid adenoma
Lee et al. [7]	Hepatocellular carcinoma	Liver	Parathyroid adenoma