Introduction: Primary thyroid lymphoma (PTL) presents between 2 and 8% of all thyroid malignancies. Rapidly enlarging neck mass, especially in women with Hashimotos thyroiditis should steer the diagnostic procedures in the way of PTL. The most common type is diffuse large B-cell lymphoma. Adrenal incidentaloma are incidentally discovered adrenal masses without prior suspicion of adrenal disease.
Case report: A 71-year-old woman with an adrenal incidentaloma was admitted to our Clinic for regular annual testing. Her incidentaloma was first diagnosed 3 years ago. Ultrasound and CT confirmed left adrenal tumor of 15 mm in size. Annual endocrine evaluations showed normal midnight cortisol and basal ACTH with adequate cortisol suppression after 1 mg-overnight dexamethason suppresion test. Plasma renin activity (PRA) and aldosterone (ALD) were also in normal range with normal ALD:PRA ratio. Normal urinary catecholamines and serum chromogranine excluded active pheochromocythoma. Annual CT visualizations showed no change in tumor size during these 3 years. For the last 7 years she was taking levothyroxine due to hypothyroidism Hashimotos thyroiditis. Her thyroid status showed good substitution with elevated antithyroglobulin and anti-thyroid peroxidase antibodies. Ultrasound revealed recently enlarged thyroid mass with normal calcitonine. Surgery was performed after fine needle cytology. Pathohistology and immunohistochemistry showed B-cell lymphoma positive for CD3, CD5, CD43, PAX5, CD20 and partially positive for bcl2, CD43, with Ki67 of 25%. After surgery she received six cycles of chemotherapy. Overall she is doing well with good prognostic features.
Conclusion: The adrenal tumor was diagnosed three years before PTL and it did not show any change in size so it is most unlikely that this incidentaloma was of B cell lymphoma origin. According to the available literature this is the first case of PTL in a patient with most likely benign, nonfunctional adrenal incidentaloma.