Parathyroid cancer pathophysiology: Difference between revisions
Jump to navigation
Jump to search
No edit summary |
No edit summary |
||
| Line 3: | Line 3: | ||
{{CMG}}; {{AE}} {{Ammu}} | {{CMG}}; {{AE}} {{Ammu}} | ||
==Overview== | ==Overview== | ||
On gross pathology, stony-hard consistency, lobulation, and dense, fibrous, grayish-white capsule are characteristic findings of parathyroid cancer. On microscopic histopathological analysis, | 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. | dense fibrous trabeculae, [[mitoses]], and capsular invasions are characteristic findings of parathyroid cancer. | ||
==Pathogenesis== | ==Pathogenesis== | ||
* Parathyroid cancer typically runs an indolent course because the tumor has a rather low malignant potential. | * Parathyroid cancer typically runs an indolent course because the [[tumor]] has a rather low malignant potential. | ||
* At initial presentation, very few patients with parathyroid carcinoma have metastases either to regional lymph nodes (<5%) or distant sites (<2%). | * At initial presentation, very few patients with parathyroid carcinoma have [[metastases]] either to regional [[lymph nodes]] (<5%) or distant sites (<2%). | ||
* A higher proportion of parathyroid cancers locally invade the thyroid gland, overlying strap muscles, recurrent laryngeal nerve, trachea, or esophagus. Parathyroid carcinoma tends to be localized in the inferior parathyroid glands; one series reported that the primary tumor originating in the inferior parathyroid glands was found in 15 of 19 cases involving local invasion. | * A higher proportion of parathyroid cancers locally invade the [[thyroid gland]], overlying strap muscles, recurrent laryngeal nerve, [[trachea]], or [[esophagus]]. Parathyroid carcinoma tends to be localized in the inferior parathyroid glands; one series reported that the primary tumor originating in the inferior parathyroid glands was found in 15 of 19 cases involving local invasion. | ||
* Approximately 40% to 60% of patients experience a postsurgical recurrence, typically in the range of 2 to 5 years after the initial resection. In most cases, hypercalcemia precedes physical evidence of recurrent disease. | * Approximately 40% to 60% of patients experience a postsurgical recurrence, typically in the range of 2 to 5 years after the initial resection. In most cases, [[hypercalcemia]] precedes physical evidence of recurrent disease. | ||
* The location of recurrence is typically regional, either in the | * The location of recurrence is typically regional, either in the [[tissue]] of the [[neck]] or in cervical [[lymph node]], and accounts for approximately two thirds of recurrent cases. Distant [[metastases]] were reported to occur in 25% of patients, primarily in the lungs but also in the [[bone]] and [[liver]]. Serum parathyroid hormone levels may be 3 to 10 times above the upper limit of normal and hence cause [[nephrolithiasis]] or [[nephrocalcinosis]]. | ||
==Genetics== | ==Genetics== | ||
* HRPT2/CDC73 gene is involved in the pathogenesis of parathyroid cancer. | * ''HRPT2/CDC73'' gene is involved in the pathogenesis of parathyroid cancer. | ||
==Associated Conditions== | ==Associated Conditions== | ||
* Multiple endocrine neoplasia 1 | * [[Multiple endocrine neoplasia 1]] | ||
* Autosomal dominant familial isolated hyperparathyroidism | * Autosomal dominant familial isolated [[hyperparathyroidism]] | ||
==Gross Pathology== | ==Gross Pathology== | ||
* Operatively, parathyroid cancers may be distinguished from adenomas by their firm, stony-hard consistency and lobulation. | * Operatively, parathyroid cancers may be distinguished from adenomas by their firm, stony-hard consistency and lobulation. | ||
* In most series, the median maximal diameter of parathyroid carcinoma is between 3.0 cm and 3.5 cm compared with approximately 1.5 cm for benign adenomas. | * In most series, the median maximal diameter of parathyroid carcinoma is between 3.0 cm and 3.5 cm compared with approximately 1.5 cm for benign adenomas. | ||
* In approximately 50% of the patients, the malignant tumor is surrounded by a dense, fibrous, grayish-white capsule that infiltrates adjacent tissues. The clinical features of parathyroid carcinoma are caused primarily by the effects of excessive secretion of parathormone (PTH) by the tumor rather than by the infiltration of vital organs by tumor cells. | * In approximately 50% of the patients, the malignant tumor is surrounded by a dense, fibrous, grayish-white capsule that infiltrates adjacent tissues. The clinical features of parathyroid carcinoma are caused primarily by the effects of excessive secretion of [[parathormone]] (PTH) by the [[tumor]] rather than by the infiltration of vital organs by tumor cells. | ||
==Microscopic Pathology== | ==Microscopic Pathology== | ||
* Histopathologically, as with other endocrine neoplasms, the distinction between benign and malignant parathyroid tumors is difficult to make. | * Histopathologically, as with other endocrine neoplasms, the distinction between benign and malignant parathyroid tumors is difficult to make. | ||
Revision as of 15:58, 29 December 2015
|
Parathyroid cancer Microchapters |
|
Diagnosis |
|---|
|
Treatment |
|
Case Studies |
|
Parathyroid cancer pathophysiology On the Web |
|
American Roentgen Ray Society Images of Parathyroid cancer pathophysiology |
|
Risk calculators and risk factors for Parathyroid cancer pathophysiology |
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Ammu Susheela, M.D. [2]
Overview
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.
Pathogenesis
- Parathyroid cancer typically runs an indolent course because the tumor has a rather low malignant potential.
- At initial presentation, very few patients with parathyroid carcinoma have metastases either to regional lymph nodes (<5%) or distant sites (<2%).
- A higher proportion of parathyroid cancers locally invade the thyroid gland, overlying strap muscles, recurrent laryngeal nerve, trachea, or esophagus. Parathyroid carcinoma tends to be localized in the inferior parathyroid glands; one series reported that the primary tumor originating in the inferior parathyroid glands was found in 15 of 19 cases involving local invasion.
- Approximately 40% to 60% of patients experience a postsurgical recurrence, typically in the range of 2 to 5 years after the initial resection. In most cases, hypercalcemia precedes physical evidence of recurrent disease.
- The location of recurrence is typically regional, either in the tissue of the neck or in cervical lymph node, and accounts for approximately two thirds of recurrent cases. Distant metastases were reported to occur in 25% of patients, primarily in the lungs but also in the bone and liver. Serum parathyroid hormone levels may be 3 to 10 times above the upper limit of normal and hence cause nephrolithiasis or nephrocalcinosis.
Genetics
- HRPT2/CDC73 gene is involved in the pathogenesis of parathyroid cancer.
Associated Conditions
- Multiple endocrine neoplasia 1
- Autosomal dominant familial isolated hyperparathyroidism
Gross Pathology
- Operatively, parathyroid cancers may be distinguished from adenomas by their firm, stony-hard consistency and lobulation.
- In most series, the median maximal diameter of parathyroid carcinoma is between 3.0 cm and 3.5 cm compared with approximately 1.5 cm for benign adenomas.
- In approximately 50% of the patients, the malignant tumor is surrounded by a dense, fibrous, grayish-white capsule that infiltrates adjacent tissues. The clinical features of parathyroid carcinoma are caused primarily by the effects of excessive secretion of parathormone (PTH) by the tumor rather than by the infiltration of vital organs by tumor cells.
Microscopic Pathology
- Histopathologically, as with other endocrine neoplasms, the distinction between benign and malignant parathyroid tumors is difficult to make.
- Features such as dense fibrous trabeculae, trabecular growth patterns, mitoses, and capsular invasions, which have been classically associated with carcinomas, have also been found in parathyroid adenomas.
- Capsular and vascular invasion appears to correlate best with tumor recurrence.