Endocrine Abstracts

Background: Cancer of thyroid gland is rare in childhood, representing 1% of all pediatric malignancies. Primary thyroid lymphoma (PTL) is even rarer accounting for 5% of thyroid malignancies and 2% of extranodal lymphomas. The disease affects mainly adults in thesixth orseventh decade of life, with a female predominance. Most thyroid lymphomas are non-Hodgkin’s lymphomas (nHL) of B-cell origin. The most common type is Diffuse Large B- cell Lymphoma (DLBCL). Patients with Hashimoto’s thyroiditis (HT) are at greater risk for developing PTL.

Objectives and methods: We describe the case of DLBCL of thyroid in an adolescent girl with a history of HT. To our best of our knowledge, DLBCL in a young child has not been reported in the medical literature.

Results: A 12 -years- old girl with known HT for the last 9 years admitted to our department with a right sided painless progressive swelling of the neck. The physical and ultrasound examination revealed an enlarged thyroid gland and right lymphadenopathy. Full blood count, renal, liver and thyroid function tests were normal while anti-thyroglobulin and thyroid peroxidase antibodies were positive. She has been receiving treatment with levothyroxine since the age of 3. Two FNAs were performed showing suspected lymphoblastic lesions for nHL without precise diagnosis. A neck CT scan revealed a nodular alteration max diameter 2.95 × 3.9 × 5.2 cm of the right thyroid gland and multiple lymph nodes in the neck highly suspicious of the above diagnosis. PET/CT scan confirmed these findings with SUV max = 16.5 and 2.5 in the right thyroid gland and lymph nodes respectively. Ultra-sound guided core needle biopsy was finally performed confirming the diagnosis of DLBCL. CSF analysis showed no tumor cells and the bone marrow aspiration was negative. She was treated according to LMB 2000 – group B protocol with one course COP, two courses COPADM and two courses CYM chemotherapy with no surgical removal of thyroid. The patient had a good response to the treatment with a rapid decrease in the size of the thyroid mass. She is well in herself 8 months post initial diagnosis.

Conclusion: PTLis a rare cause of thyroid malignancy and extranodal lymphomas. However, it should be considered at differential diagnosis of a thyroid mass in patients presenting with a rapidly enlarging neck mass and a history of HT. It is a treatable condition with an excellent prognosis even with the aggressive histological subtypes with no need of thyroidectomy.