Parathyroid carcinosarcoma: a rare form of parathyroid carcinoma with normal parathyroid hormone levels

Parathyroid carcinosarcoma was first described by Nacamuli et al in 2002. We present the second case of this rare disease. This rare carcinosarmoca presented as a parathyroid carcinoma with uncharacteristically normal parathyroid hormone levels. The patient is a 57-year-old woman with long-standing right-sided vocal cord paralysis presented with a progressive 3 × 2 × 3 cm mass in the right neck. She had previously undergone a total thyroidectomy revealing benign pathology. Parathyroid hormone and calcium blood levels were within normal limits. The mass was removed with negative surgical margins. Histopathology and immunohistochemical analysis showed a biphasic pattern, with positive for chromogranin and vimentin, consistent with carcinoma and sarcoma. The disease in our patient, as in the previously reported case, has shown systemic progression despite aggressive surgical resection and adjuvant therapy.