Table 2.
Epidemiological, clinical, pathological, and prognostic features of patients with parathyroid involvement by thyroid cancer: review of the literature.
| Tang et al., 2002 (Ref. [4]) | Kakudo et al., 2004 (Ref. [5]) | Ito et al., 2009 (Ref. [6]) | Chrisoulidou et al., 2012 (Ref. [7]) | Present study | Total/conclusions | |
|---|---|---|---|---|---|---|
| Rate of parathyroid involvement in thyroid cancer patients | 2.2% | 3.9% | 1.6% | 0.5% | 0.4% | Range: 0.4–3.9% |
| Number of patients enrolled | 20 | 14 | 30 | 10 | 10 | 84 |
| Sex | 14 F, 6 M | 10 F, 4 M | Not reported | 8 F, 2 M | 7 F, 3 M | F to M ratio: 2.3–4 to 1 |
| Mean age (yrs) | 52 | 60.4 | Not reported | 52.2 | 55 | Range: 52–60.4 |
| Primary tumor histotype | 20 PTC | 14 PTC | 30 PTC | 6 PTC 3 FTC 1 ATC |
10 PTC | 80 out of 84 cancers are PTC |
| Primary tumor size | >1 cm 14 ≤1 cm 6 |
2.5 cm (mean) | >1 cm 22 ≤1 cm 8 |
2.5 cm (mean) | 2.4 cm (mean) >1 cm 10 |
Microcarcinomas are uncommon |
| Extrathyroid invasion of tissues other than parathyroid | 10 yes 10 no |
13 yes 1 no |
8 yes 22 no |
9 yes 1 no |
6 Yes 4 no |
46 yes 38 no |
| Lymph node metastases | 17 yes 3 no |
13 yes 1 no |
1 yes 29 no |
5 yes 5 no |
3 yes 7 no |
39 yes 45 no |
| Distant metastases | 1 yes 19 no |
2 yes 12 no |
0 yes 30 no |
2 yes 2 no |
0 yes 10 no |
5 yes 79 no |
| Patterns of parathyroid involvement | Pattern A 15 Pattern B 3 Pattern C 2 |
Pattern A 10 Pattern B 3 Pattern C 1 |
Not reported | Pattern A + B 9 Pattern C 1 |
Pattern A 6 Pattern B 1 Pattern A + B 3 |
Pattern A + B 90–100% Pattern C 0–10% |
| Stage* | Not reported | I/II 2 III/IV 12 |
pT3 30/30 | I/II 3 III/IV 7 |
I 2 III 8 |
— |
| Recurrence | Not reported | 2 yes 12 no |
1 yes 29 no |
Not reported | 0 yes 10 no |
Most cases do not recur |
| 10-yr disease free survival rate | Not reported | 80.8% | >95% | Not reported | N/A | >80% in the reported cases |
ATC: anaplastic thyroid carcinoma; F: female; FTC: follicular thyroid carcinoma; M: male; N/A: not applicable; PTC: papillary thyroid carcinoma; Pattern A: direct invasion by infiltrative growth from the primary thyroid carcinoma to parathyroid; Pattern B: extension of thyroid malignancy into the parathyroid, in which cancer nests are separated from by a pseudocapsule; Pattern C: true thyroid cancer metastasis within the parathyroid, with no evidence of continuity from the primary thyroid tumor; Ref.: reference. *Based on AJCC/International Union against Cancer (AJCC/UICC) classification system [11].