# Radiation Oncology/NHL/Thyroid

Thyroid Lymphoma

## Background

Lymphomas make up only 2% of all thyroid gland malignancies. Thryoid gland lymphomas make up only 2% of extranodal lymphomas. Associated with Hashimoto's thyroiditis

## Pathology

Nearly all thyroid lymphomas are B-cell Non-Hodgkin's lymphoma; Hodgkin's lymphoma of the thyroid and T cell lymphomas have been reported but are very rare.
60-80% are DLBCL; 30% are extranodal marginal zone lymphoma; <10% follicular lymphoma. Extranodal marginal zone lymphoma (MALT type) is most commonly associated with Hashimoto's.

## Staging

50% - Stage IE (limited to thyroid gland) 45% - Stage IIE (limited to thyroid gland and regional nodes) 5% - Stage III/IV

## Treatment results

Case Series:
* Royal Marsden Hospital; 2005 (1936-96) PMID 15845932 -- "Management of non-Hodgkin's lymphoma of the thyroid: the Royal Marsden Hospital experience." (Harrington KJ, Br J Radiol. 2005 May;78(929):405-10.)
** 91 pts, retrospective. Stage I-II in 91% (38%/53%). Path = not reviewed or reclassified. 91% were intermediate or high grade.
** Treatment: 89 pts received RT. 27 pts received chemotherapy (13 planned, either prior to or following RT; 14 for relapse after RT; 2 chemo alone). RT was EFRT (modified mantle) in 64, IFRT (thyroid + neck) in 25. Dose: median 40 Gy.
** 5-yr OS 48%, median RFS 34 mo. Multivariate analysis for OS: Stage, Debulking Surgery, EFRT (HR=0.45) vs IFRT. Dose was not significant for OS but was sig. for LC. 52% of pts with IFRT had LRF (20% local alone, 32% L+D) vs 26% for EFRT (9% local alone, 17% L+D).
** Conclusion: IFRT should be abandoned in favor of EFRT. Suggest dose of 40 Gy in 20 fractions. EFRT alone is effective for Stage I but not Stage II. For Stage II or higher, chemotherapy followed by EFRT is recommended.
* MDACC; 2001 (1959-94) PMID 11241227 -- "Localized non-Hodgkin lymphoma involving the thyroid gland." (Ha CS, Cancer. 2001 Feb 15;91(4):629-35.)
** 51 pts, retrospective. Stage I-II (41%/59%). Path = Working Formulation: DLCL in 60%; 96% were intermediate or high grade. A subset(n=13) of pts were retroactively classified by immunophenotype and 28 were reclassified according to the WHO classification.
** Treatment: 24 chemo+RT, 18 pts surgery+RT, 5 chemo alone, 4 surgery alone. RT was modified mantle in 34, involved field in 8. Dose: median 42 Gy in 21 fractions.
** Median f/u 10 yrs (23 yrs for RT alone, 8 yrs for CMT). OS 5 yrs 64%, 10 yrs 49% (Stage I 80%@5y,55%@10y; Stage II 53%/45%); CSS 75%/75%; FFS 76%/76% (Stage I 88%/88%; Stage II 68%/68%). FFS at 5 and 10y was 91% for CMT, 76% for RT alone, and 50% for chemo alone (NS).
** Conclusion: excellent prognosis for Stage I/II pts treated with CMT. Distant recurrence is common. IPI was a significant prognostic factor.
* Princess Margaret Hospital; 1993 PMID 8226154 -- "Non-Hodgkin's lymphoma of the thyroid gland: prognostic factors and treatment outcome. The Princess Margaret Hospital Lymphoma Group." (Tsang RW, Int J Radiat Oncol Biol Phys. 1993 Oct 20;27(3):599-604.)
* Royal Marsden Hospital; 1986 PMID 3759532 -- "Primary lymphoma of the thyroid: clinical features, prognostic factors, and results of treatment." (Tupchong L, Int J Radiat Oncol Biol Phys. 1986 Oct;12(10):1813-21.)
* 1986 PMID 2428787 -- "Thyroid lymphomas stages IE and IIE: comparative results for radiotherapy only, combination chemotherapy only, and multimodality treatment." (Vigliotti A, Int J Radiat Oncol Biol Phys. 1986 Oct;12(10):1807-12.)
* Mayo; 1985 PMID 3918965 -- "Radiotherapeutic management of primary thyroid lymphoma." (Blair TJ, Int J Radiat Oncol Biol Phys. 1985 Feb;11(2):365-70.)
Clinicopathologic Studies:
* AFIP; 2000 PMID 10800981 -- "Malignant lymphoma of the thyroid gland: a clinicopathologic study of 108 cases. (Derringer GA, Am J Surg Pathol. 2000 May;24(5):623-39.)
* Royal Marsden Hospital / British National Lymphoma Investigation (BNLI); 1994 PMID 7826922 -- "The significance of MALT histology in thyroid lymphoma: a review of patients from the BNLI and Royal Marsden Hospital." (Laing RW, Clin Oncol (R Coll Radiol). 1994;6(5):300-4.)
* Christie Hospital (UK); 1992 PMID 1555984 -- "Primary malignant lymphoma of the thyroid: a clinicopathological analysis." (Logue JP, Int J Radiat Oncol Biol Phys. 1992;22(5):929-33.)
* 1985 PMID 3906977 -- "Malignant lymphoma of the thyroid gland: a clinical and pathologic study of twenty cases." (Rasbach DA, Surgery. 1985 Dec;98(6):1166-70.)
Reviews:
* University of Calgary; 2007 PMID 17235456 -- "An evidence-based approach to the treatment of thyroid lymphoma." (Mack LA, World J Surg. 2007 May;31(5):978-86.)
* Yale; 1994 PMID 8275426 Full text -- "Thyroid lymphoma. The case for combined modality therapy." (Doria R, Cancer. 1994 Jan 1;73(1):200-6.)