Parathyroid Glands - Pathology

Anatomy and Physiology

Anatomy and Physiology of the Parathyroid glands can be found here.

Pseudo-Hyperparathyroidism

• Non-endocrine tumours may be capable of secreting hormones, or hormone-like factors.
  • A parathormone-like substance may be secreted in such a manner.

Apocrine Gland Adenocarcinoma

• Malignant tumours of the anal sac apocrine glands can produce PTH-related peptide (PTHrp).
  • This induces a pseudo-hyperparathyroidism and hypercalcaemia.

Lymphosarcoma

• 10 to 40% of cases in dogs may cause a pseudo-hyperparathyroidism.

Other Carcinomas

Some other carcinomas may also be capable of causing pseudo-hyperparathyroidism.

Hypoparathyroidism

• Hypoparathyroidism may result from primary gland hypofunction.
  • Gland hypofunction occurs due to:
    1. Destruction of secretory cells by a disease process.
       • For example, this may be immune mediated, or another inflammatory cause.
    2. A biochemical defect in synthetic pathway of the hormone.
       • These are usually genetic aberrations.
       • Defects in synthesis are not commonly identified in the veterinary species.