Table 2. Prevalence and clinicopathological distribution of primary thyroid lymphomas.
| Parameters | Asian studies | Western studies |
|---|---|---|
| Prevalence of PTL | 2% of thyroid malignancies and 0.4% all lymphomas (11,12) | 2.3–3.5% of thyroid malignancies and 2.1–2.6% of all lymphomas (27,28,30,34,35) |
| Histological subtypes (%) | ||
| MALT lymphoma | 41.10 | 12.40 |
| DLBCL | 32.90 | 66.00 |
| Mixed lymphomas (MALT lymphoma /FL with DLBCL) | 4.40 | 5.90 |
| FL | 1 | 7.90 |
| CLL | – | 2.50 |
| BL | – | 0.20 |
| MCL | – | 0.05 |
| Plasmacytoma | 0.30 | 0.80 |
| HL | – | 1.90 |
| NHL-HG | 2.80 | 0.75 |
| NHL-IG | 11.50 | – |
| NHL-LG | 3.80 | 0.70 |
| B-NHL | 0.10 | 0.60 |
| PTLL | 0.10 | – |
| PTCL NOS | 0.30 | 0.20 |
| NK/T | – | 0.10 |
| ALCL | 1.70 | – |
| Stage at presentation (%) | ||
| I | 45.70 | 57.50 |
| II | 51.30 | 30.30 |
| III | 0.90 | 2.80 |
| IV | 2.10 | 9.40 |
PTL, Primary thyroid lymphoma; MALT, Mucosa-associated lymphoid tissue; FL, follicular lymphoma; CLL, chronic lymphocytic leukemia; BL, Burkitt lymphoma; MCL, mantle cell lymphoma; HL, Hodgkin lymphoma; NHL, Non-Hodgkin lymphoma; HG, high grade; IG, intermediate grade; LG, low grade; PTLL, primary T-cell lymphoblastic lymphoma; PTCL NOS, primary T-cell lymphoma, not otherwise specified; NK/T, NK/T cell lymphoma; ALCL, anaplastic large cell lymphoma.