Article

Perioperative characteristics, histological diagnosis, and outcome in cats undergoing surgical treatment of primary hyperparathyroidism

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  • Veterinary Specialty Hospital - North County
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Abstract

Objective To report perioperative characteristics, complications, histopathologic diagnosis and outcome in cats undergoing surgical treatment for primary hyperparathyroidism (PHPT). Study design Multi‐institutional, retrospective case series. Animals Thirty‐two client‐owned cats. Methods Medical records of cats treated with surgical removal of 1 or more parathyroid gland(s) with confirmed histopathologic evaluation were reviewed. Cats were divided into preoperative ionized calcium (iCa) groups corresponding to the 33rd, 67th, and 100th percentiles of the preoperative iCa results of the study population. Follow‐up consisted of phone conversation with owners or primary veterinarian. Results Ionized calcium was above reference range in all cats (median 1.8 mmol/L [interquartile range, 1.5–1.9]). Abnormal tissue was excised after cervical exploration in all cats. The most common histopathologic diagnoses were parathyroid adenoma in 20 of 32 (62.5%) cats and parathyroid carcinoma in 7 of 32 (21.9%) cats. At discharge, 6 of 32 (18.8%) cats had hypercalcemia, 5 of 32 (15.6%) had hypocalcemia, and 21 of 32 (65.6%) were normocalcemic. Preoperative iCa did not correlate with postoperative iCa. The median follow‐up time was 332 days (range, 7–3156). Overall median survival time was 1109 days (95% CI, 856–1332). Survival time was not associated with preoperative iCa group, hypocalcemia at discharge, hypercalcemia at discharge, or diagnosis of carcinoma. Conclusion In this cohort of cats, parathyroid adenoma was the most common cause of PHPT, and surgical treatment resulted in very good median survival time. Preoperative iCa was not predictive of postoperative hypocalcemia. Clinical significance Surgical parathyroidectomy for treatment of PHPT in cats provides a favorable prognosis.

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... Primary hyperparathyroidism is rarely reported in cats. [1][2][3][4][5][6][7] It is caused by overproduction of PTH due to parathyroid gland hyperplasia or an autonomously functioning parathyroid adenoma, cystadenoma or carcinoma, with adenoma being the most common and carcinoma the rarest form. 1,3-6,8-10 To our knowledge, this is the first case report of a bilateral parathyroid cystic carcinoma in a cat. ...
... No specific breed predispositions have been described. 1 Clinical signs include lethargy, anorexia, vomiting and weight loss, 1,3,6,7,11 and 37.5% of affected cats have a palpable mass in the cervical region. 1 Despite the bilateral and malignant presentation of the disease in this case, the only reported sign was chronic vomiting. ...
... 1 Clinical signs include lethargy, anorexia, vomiting and weight loss, 1,3,6,7,11 and 37.5% of affected cats have a palpable mass in the cervical region. 1 Despite the bilateral and malignant presentation of the disease in this case, the only reported sign was chronic vomiting. ...
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No other title offers such dedication to the depth, experience, and focus of endocrinology as Canine and Feline Endocrinology, 4th Edition. Comprehensive coverage includes virtually every common and uncommon condition in endocrinology, plus the most updated information on nutrition, geriatric care, pathophysiology, testing procedures, and cost-effective and expedient diagnostic protocols. With its logical, step-by-step guidance for decision making, diagnosis, and prescribing, you will be well-equipped to care for the wide spectrum of endocrine and metabolic disorders in dogs and cats. © 2015 by Saunders, an imprint of Elsevier Inc. All rights reserved.
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In primary hyperparathyroidism, calcium homeostasis is disrupted by excessive synthesis and secretion of parathyroid hormone (PTH), which is usually caused by a solitary adenoma, or less often by nodular hyperplasia or carcinoma of the parathyroid glands. So far, the distinction between these forms of primary hyperparathyroidism has been made by histological examination. In this report clinical and histological findings, including PTH immunohistochemistry, are described in five dogs with primary hyperparathyroidism, three dogs with secondary hyperparathyroidism due to chronic renal failure, and eight control dogs. In the dogs with primary hyperparathyroidism, nodular adenomatous hyperplasia was found in two animals and parathyroid adenoma in three. The dogs with chronic renal failure had diffuse parathyroid gland hyperplasia. The parathyroid glands of the control dogs and the inactive cells surrounding the hyperplastic nodules showed slight to moderate, localized, paranuclear PTH immunolabelling. In the primary nodular and secondary diffuse hyperplasia, all parathyroid cells had a diffuse cytoplasmic PTH labelling pattern, sometimes in combination with localized paranuclear labelling. In parathyroid adenoma, areas with either paranuclear labelling or diffuse cytoplasmic labelling were observed. As both parathyroid adenoma and primary nodular parathyroid gland hyperplasia have characteristics of intrinsic autonomy (i.e., suppression of the remaining endocrine tissue), there would seem to be no functional difference between the two abnormalities. It is argued that primary (multi)nodular hyperplasia is a multiple form of parathyroid adenoma.
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Reports of cystic thyroid and parathyroid masses in cats are uncommon. Herein, the authors describe a series of four cats with cystic ventral cervical lesions, among them thyroid cyst (n=1), thyroid cystadenoma (n=2), and parathyroid adenocarcinoma (n=1). Presentations ranged from completely asymptomatic cervical swellings to signs related to local compression of adjacent structures (e.g., trachea). Ultrasonographic evaluation was helpful in localization of the mass in two cases. Hormone analysis and concentration of cystic fluid were performed in one cat. Surgical excision was performed successfully in three cases. Histopathological examination was performed in all four cases. Long-term prognosis was excellent for those cases in which follow-up was available.
Article
To review the records of 29 dogs diagnosed with primary hyperparathyroidism and see if any factors correlate with renal failure. Dogs were selected retrospectively from case files from the QVSH and the QMH. The majority of dogs were middle-aged and four were keeshonds. The primary presenting complaints were polyuria and polydipsia. All dogs had an elevated total and ionised plasma calcium concentration. Plasma phosphate concentrations were variable. Ultrasonography of the parathyroid gland revealed nodular enlargement which was found to correlate well with surgical findings. The majority of dogs underwent surgical parathyroidectomy. Five cases were treated by ultrasound-guided chemical ablation of the parathyroid gland, of which only two cases showed a partial response. Three dogs were euthanased within a week of presentation. Seven other dogs had renal failure diagnosed either at presentation or up to six months after parathyroidectomy. The development of renal failure was correlated with total calcium concentration but did not correlate with any other factor, including the calcium phosphate product. Thirteen treated dogs were known to be alive at the time of writing, which was six months to 3.5 years after parathyroidectomy. Primary hyperparathyroidism cases with high total calcium were more likely to develop renal failure in this group of dogs; however, the calcium phosphate product did not seem to be a useful predictor. Ultrasound-guided chemical ablation seemed to have limited advantage over surgery.
Article
To evaluate pretreatment clinical and laboratory findings in dogs with naturally occurring primary hyperparathyroidism. Retrospective study. 210 dogs with primary hyperparathyroidism and 200 randomly selected, age-matched control dogs that did not have primary hyperparathyroidism. Medical records for dogs with primary hyperparathyroidism were reviewed for signalment; clinical features; and results of clinicopathologic testing, serum parathyroid hormone assays, and diagnostic imaging. Mean age of the dogs with primary hyperparathyroidism was 11.2 years (range, 6 to 17 years). The most common clinical signs were attributable to urolithiasis or urinary tract infection (ie, straining to urinate, increased frequency of urination, and hematuria). Most dogs (149 [71%]) did not have any observable abnormalities on physical examination. All dogs had hypercalcemia, and most (136 [65%]) had hypophosphatemia. Overall, 200 of the 210 (95%) dogs had BUN and serum creatinine concentrations within or less than the reference range, and serum parathyroid hormone concentration was within reference limits in 135 of 185 (73%) dogs in which it was measured. Urolithiasis was identified in 65 (31 %) dogs, and urinary tract infection was diagnosed in 61 (29%). Mean serum total calcium concentration for the control dogs-was significantly lower than mean concentration for the dogs with primary hyperparathyroidism, but mean BUN and serum creatinine concentrations for the control dogs were both significantly higher than concentrations for the dogs with primary hyperparathyroidism. Results suggest that urolithiasis and urinary tract infection may be associated with hypercalcemia in dogs-with primary hyperparathyroidism, but that development of renal insufficiency is uncommon.
Article
The medical records of 110 dogs treated for primary hyperparathyroidism were reviewed. Dogs were treated via parathyroidectomy (n=47), percutaneous ultrasound-guided ethanol ablation (n=15), or percutaneous ultrasound-guided heat ablation (n=48). Forty-five of 48 (94%) parathyroidectomies resulted in control of hypercalcemia for a median of 561 days. Thirteen of 18 (72%) ethanol ablation procedures resulted in control of hypercalcemia for a median of 540 days. Forty-four of 49 (90%) heat-ablation treatments resulted in control of hypercalcemia for a median of 581 days.
Fluoroscopic guided differential venous sampling of parathyroid hormone for diagnosis of persistent hyperparathyroidism following parathyroidectomy
  • J Howard
  • K Ham
  • S Jones
Howard J, Ham K, Jones S. Fluoroscopic guided differential venous sampling of parathyroid hormone for diagnosis of persistent hyperparathyroidism following parathyroidectomy. In: Proceedings of the Society of Soft Tissue Veterinary Surgery Annual Conference; June 15-17, 2017; Whitefish, MT.
Feline hyperparathyroidism: pathophysiology, diagnosis, and treatment of primary and secondary disease
  • V Parker
  • C Gilor
  • DJ Chew
Parker V, Gilor C, Chew DJ. Feline hyperparathyroidism: pathophysiology, diagnosis, and treatment of primary and secondary disease. J Feline Med Surg. 2015;17(5):427-439.
Fluoroscopic guided differential venous sampling of parathyroid hormone for diagnosis of persistent hyperparathyroidism following parathyroidectomy
  • Joness Howardj Hamk