Incidence, survival time, and surgical treatment of parathyroid carcinomas in dogs: 100 cases (2010–2019)

Abstract

OBJECTIVE To evaluate outcomes of dogs with parathyroid carcinoma (PTC) treated by surgical excision and to describe the incidence of postoperative hypocalcemia, degree of hypocalcemia, duration of hospitalization, duration of calcium supplementation, and survival time ANIMALS 100 client-owned dogs with PTC admitted to academic, referral veterinary institutions. PROCEDURES In a retrospective multi-institutional study, medical records of dogs undergoing surgical excision of PTC between 2010 to 2019 were reviewed. Signalment, relevant medical history, clinical signs, clinicopathologic testing, imaging, surgical findings, intraoperative complications, histologic examination, and survival time were recorded. RESULTS 100 dogs with PTC were included, and 96 dogs had clinical or incidental hypercalcemia. Common clinical signs included polyuria (44%), polydipsia (43%), hind limb paresis (22%), lethargy (21%), and hyporexia (20%). Cervical ultrasonography detected a parathyroid nodule in 91 of 91 dogs, with a single nodule in 70.3% (64/91), 2 nodules in 25.3% (23/91), and ≥ 3 nodules in 4 (4/91)% of dogs. Hypercalcemia resolved in 89 of 96 dogs within 7 days after surgery. Thirty-four percent of dogs developed hypocalcemia, on the basis of individual analyzer ranges, within 1 week after surgery. One dog had metastatic PTC to the prescapular lymph node, and 3 dogs were euthanized for refractory postoperative hypocalcemia. Estimated 1-, 2-, and 3-year survival rates were 84%, 65%, and 51% respectively, with a median survival time of 2 years. CONCLUSIONS AND CLINICAL RELEVANCE Excision of PTC results in resolution of hypercalcemia and excellent long-term tumor control. Surgical excision of PTC is recommended because of resolution of hypercalcemia and a good long-term prognosis. Future prospective studies and long-term follow-up are needed to further assess primary tumor recurrence, metastasis, and incidence of postoperative hypocalcemia.

Surgical description and outcome of ultrasound‐guided minimally invasive parathyroidectomy in 50 dogs with primary hyperparathyroidism

“…Four dogs had incomplete follow-up, and one dog had ongoing follow-up at the time of writing and were excluded from postoperative hypocalcemia and outcome analysis. The median age was 11 years (5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15). The median weight was 15.5 kg (3.1-63.3).…”

“…Diagnosis of PHPT requires demonstration of repeatable hypercalcemia, followed by an elevated or normal parathyroid hormone (PTH) with concurrent serum ionized calcium elevation 4,6 . Clinical signs are often vague and nonspecific, which can include, hyporexia, weakness, lethargy, polyuria, polydipsia, vomiting, and diarrhea 1,3,7,9–13 . If calcium oxalate urinary stones are present, then the animal may also display signs of lower urinary tract disease 1,9–11 …”

“…Clinical signs are often vague and nonspecific, which can include, hyporexia, weakness, lethargy, polyuria, polydipsia, vomiting, and diarrhea 1,3,7,9–13 . If calcium oxalate urinary stones are present, then the animal may also display signs of lower urinary tract disease 1,9–11 …”

“…4,6 Clinical signs are often vague and nonspecific, which can include, hyporexia, weakness, lethargy, polyuria, polydipsia, vomiting, and diarrhea. 1,3,7,[9][10][11][12][13] If calcium oxalate urinary stones are present, then the animal may also display signs of lower urinary tract disease. 1,[9][10][11] In humans, the most common surgical treatment options for PHPT are bilateral neck exploration or minimally invasive focused neck exploration.…”

“…1,3,7,[9][10][11][12][13] If calcium oxalate urinary stones are present, then the animal may also display signs of lower urinary tract disease. 1,[9][10][11] In humans, the most common surgical treatment options for PHPT are bilateral neck exploration or minimally invasive focused neck exploration. [14][15][16] Minimally invasive parathyroidectomy has the advantage of significantly lower patient discomfort, decreased surgical time, ability to be performed on an outpatient basis with equal success rates and lower complication rates when compared to bilateral neck exploration.…”