Thyroid & parathyroid
Parathyroid - general
Staging-parathyroid
Editor-in-Chief: Debra L. Zynger, M.D.
Last author update: 9 April 2019
Last staff update: 2 June 2021
Copyright: 2019-2024, PathologyOutlines.com, Inc.
PubMed Search:
Parathyroid gland staging
Cite this page: Bychkov A. Staging-parathyroid. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/parathyroidstaging.html. Accessed December 20th, 2024.
Definition / general
- Applicable to parathyroid carcinoma
- First introduced in AJCC 8th edition
- There is limited evidence on significant prognostic factors in parathyroid carcinoma
- Prognostic significance of tumor size, extent of invasion or regional lymph node involvement is unclear and studies are conflicting
- Presence of distant metastasis is the only consistent factor across the literature that is predictive of overall survival
- While TNM definitions have been established, no universal staging system is available so far; instead, AJCC / TNM includes recommendations for recording data collection variables in the cancer registry to be used to develop a formal staging system in the future
- Microscopic and macroscopic classifications of the primary tumor have not been standardized
Essential features
- T, N and M categories are established but no cancer stages defined at the moment
- Distant metastasis (M category) is the major predictor of overall survival
ICD coding
- ICD-10: C75.0 - Parathyroid gland
Primary tumor (pT)
- pTX: primary tumor cannot be assessed
- pT0: no evidence of primary tumor
- pTis: atypical parathyroid neoplasm (neoplasm of uncertain malignant potential) (see notes below)
- pT1: localized to the parathyroid gland with extension limited to soft tissue
- pT2: direct invasion into the thyroid gland
- pT3: direct invasion into recurrent laryngeal nerve, esophagus, trachea, skeletal muscle, adjacent lymph nodes or thymus
- pT4: direct invasion into major blood vessel or spine
Notes:
- Atypical parathyroid neoplasm is defined as a tumor that is histologically or clinically worrisome but does not fulfill the more robust criteria (i.e. invasion, metastasis) for carcinoma
- Generally includes tumors that have 2 or more concerning features, such as fibrous bands, mitotic figures, necrosis, trabecular growth or adherence to surrounding tissues intraoperatively
- Usually have a smaller dimension, weight and volume than carcinomas and are less likely to have coagulative tumor necrosis
Regional lymph nodes (pN)
- pNX: regional lymph nodes cannot be assessed
- pN0: no regional lymph node metastasis
- pN1: regional lymph node metastasis
- pN1a: metastasis to level VI (pretracheal, paratracheal and prelaryngeal / Delphian lymph nodes) or superior mediastinal lymph nodes (level VII)
- pN1b: metastasis to unilateral, bilateral or contralateral cervical (level I, II, III, IV or V) or retropharyngeal nodes
AJCC prognostic stage groups
- Not established in the current AJCC / TNM
Registry data collection variables
- Age at diagnosis
- Gender
- Race
- Size of primary tumor in millimeters
- Location of primary tumor: left or right and superior (upper) or inferior (lower)
- Invasion into surrounding tissue (present or absent)
- Distant metastasis
- Number of lymph nodes removed (by level)
- Number of lymph nodes positive (by level)
- Highest preoperative calcium (mg/dL)
- Highest preoperative parathyroid hormone (pg/mL)
- Lymphovascular invasion (present or absent)
- Grade (low or high)
- Weight of primary tumor (in milligrams)
- Mitotic rate
- Time to recurrence (months)
Histologic grade
- Low grade: round monomorphic nuclei with only mild to moderate nuclear size variation, indistinct nucleoli and chromatin characteristics resembling those of normal parathyroid or of adenoma
- High grade: more pleomorphism, with a nuclear size variation > 4:1; prominent nuclear membrane irregularities; chromatin alterations, including hyperchromasia or margination of chromatin; and prominent nucleoli; high grade tumors show several discrete confluent areas with nuclear changes
Board review style question #1
A patient presented with a parathyroid carcinoma directly invading thyroid and adjacent fibroadipose tissue. What is the pT category?
- pTis
- pT1
- pT2
- pT3
- pT4
Board review style answer #1
Board review style question #2
A 72 year old man presented with a 4 cm advanced parathyroid carcinoma invading trachea and thyroid and showing cervical lymph nodes metastasis along with dissemination in the lungs. What is the clinical stage as per the AJCC / TNM 8th edition?
- Stage I
- Stage II
- Stage III
- Stage IV
- Not applicable
Board review style answer #2
E. Not applicable; no AJCC / TNM staging system for parathyroid carcinoma is available so far, only standalone TNM categories
Comment Here Reference:
Staging-parathyroid
Back to top
