Parathyroid cancer overview

# Overview
Parathyroid cancer was first described by Sainton and Millot, in 1933. In 1928, the first parathyroidectomy operation was conducted by Isaac Y. Olch to treat parathyroid lesions. On gross pathology, stony-hard consistency, lobulation, and dense, fibrous, grayish-white capsule are characteristic findings of parathyroid cancer. On microscopic histopathological analysis,
dense fibrous trabeculae, mitoses, and capsular invasions are characteristic findings of parathyroid cancer. The etiology of parathyroid cancer is unknown. Parathyroid cancer must be differentiated from renal disease, immobility, and thiazides adverse effect. The incidence of parathyroid cancer is approximately 0.015 per 100,000 individuals in United States. Parathyroid cancer affects men and women equally. Common risk factors in the development of parathyroid cancer are multiple endocrine neoplasia type 1, hyperparathyroidism, and familial isolated hyperparathyroidism. The hallmark of parathyroid cancer is neck mass. A positive history of multiple endocrine neoplasiab type I, hyperparathyroidism, and previous radiation therapy to the head or neck is suggestive of parathyroid cancer. The most common symptoms of parathyroid cancer include weight loss, muscle weakness, fractures, constipation, fatigue, and bone pain. Patients with parathyroid cancer usually appear well. Physical examination of patients with parathyroid cancer is usually remarkable for lymphadenopathy and a palpable lump in the neck. Neck CT scan may be diagnostic of parathyroid cancer. Laboratory findings consistent with the diagnosis of parathyroid cancer include elevated serum calcium and serum parathyroid hormone. Findings on CT suggestive of parathyroid cancer include metastasis and invasion of surrounding tissues. The predominant therapy for parathyroid cancer is surgical resection. Adjunctive supportive therapy, chemotherapy, and radiation may be required. Supportive therapy for parathyroid cancer includes IV fluids, diuretics, and calcimimetic agents. Surgery is the mainstay of treatment for parathyroid cancer. There are no primary preventive measures available for parathyroid cancer. Secondary prevention strategy recommended following parathyroid cancer is germline DNA analysis for HRPT2/CDC73.

# Historical Perspective
Parathyroid cancer was first described by Sainton and Millot, in 1933. In 1928, the first parathyroidectomy operation was conducted by Isaac Y. Olch to treat parathyroid lesions.

# Pathophysiology
On gross pathology, stony-hard consistency, lobulation, and dense, fibrous, grayish-white capsule are characteristic findings of parathyroid cancer. On microscopic histopathological analysis,
dense fibrous trabeculae, mitoses, and capsular invasions are characteristic findings of parathyroid cancer.

# Causes
The etiology of parathyroid carcinoma is unknown.

# Differential Diagnosis
Parathyroid cancer must be differentiated from renal disease, immobility, and thiazide adverse effect.

# Epidemiology and Demographics
The incidence of parathyroid cancer is approximately 0.015 per 100,000 individuals in United States. Parathyroid cancer affects males and females equally.

# Risk Factors
Common risk factors in the development of parathyroid cancer are multiple endocrine neoplasia type 1, hyperparathyroidism, and familial isolated hyperparathyroidism.

# Natural history, Complications and Prognosis
Depending on the extent of the tumor at the time of diagnosis, the prognosis may vary. However,  the prognosis is generally regarded as good. Common complications of parathyroid cancer  include hypercalcemia, metastasis, and death.

# Diagnostic Criteria
The diagnosis of parathyroid cancer is made when if any of the following 5 diagnostic criteria are met: Hypercalcemia greater than 14 milligrams per deciliter, serum parathyroid hormone levels greater than twice that of normal, a palpable cervical mass in a hypercalcemic patient, unilateral vocal cord paralysis with hypercalcemia, and concomitant renal and skeletal disease observed in a patient with a markedly elevated serum parathyroid hormone.

# Staging
The staging of parathyroid cancer is based on whether there is localized or metastatic disease.

# History and Symptoms
The hallmark of parathyroid cancer is a neck mass. A positive history of multiple endocrine neoplasia type I, hyperparathyroidism, and previous radiation therapy to the head or neck is suggestive of parathyroid cancer. The most common symptoms of parathyroid cancer include weight loss, muscle weakness, fractures, constipation, fatigue, and bone pain.

# Physical Examination
Patients with parathyroid cancer usually appear well. Physical examination of patients with parathyroid cancer is usually remarkable for lymphadenopathy and palpable lump in the neck.

# Laboratory Findings
Laboratory findings consistent with the diagnosis of parathyroid cancer include elevated serum calcium and serum parathyroid hormone.

# Chest Xray
On chest x-ray, parathyroid cancer is characterized by metastases into lungs and bones.

# CT
Neck CT scan may be diagnostic of parathyroid cancer.

# MRI
MRI scan may be diagnostic of parathyroid cancer. Findings on MRI suggestive  of parathyroid cancer include metastasis and invasion of surrounding tissues.

# Echocardiography or Ultrasound
Neck ultrasound may be helpful in the diagnosis of parathyroid cancer. Findings on neck ultrasound suggestive of parathyroid cancer include structural irregularities of parathyroid gland and invasion of the surrounding tissues.

# Other Imaging Findings
Other imaging studies for parathyroid cancer include sestamibi scan, venous sampling, or PET scan.

# Medical Therapy
The predominant therapy for parathyroid cancer is surgical resection. Adjunctive supportive therapy, chemotherapy, and radiation may be required. Supportive therapy for parathyroid cancer includes IV fluids, diuretics, and calcimimetic agents.

# Surgery
Surgery is the mainstay of treatment for parathyroid cancer.

# Primary Prevention
There are no primary preventive measures available for parathyroid cancer.

# Secondary Prevention
Secondary prevention strategy recommended following parathyroid cancer is germline DNA analysis for HRPT2/CDC73.

# Reference