SUN-627 Unexpected Presentation of a Primary Thyroid T-Cell Lymphoma

Background Thyroid T-cell lymphoma is an unusual diagnosis, responsible for less than 2% of all thyroid malignancies and all extra-nodal lymphomas. Hashimoto’s thyroiditis may predispose patients to its development, but only half of the cases reported were associated with it. We present a case of a 42 years old man with generalized skin rash with subsequent development of a rapidly growing anterior neck mass arising from the thyroid gland without TFT impairments. Ultimately, an excisional cervical node biopsy disclosed immune-pathological characteristics of Angioimmunoblastic T-cell lymphoma. Clinical Course A 42 y/o Hispanic male patient without past medical history, presents for the first time complaining of a generalized intense pruritic-excoriated skin rash of 3-week duration. Rest of physical examination and biochemical test were unremarkable. Five weeks later, he reports worsening skin rash and rapid enlargement of a painless anterior neck mass. Review of systems was non contributory. An enormous, not previously palpated, left thyroid mass and a cervical lymphadenopathy was found. Laboratory data reported leukocytosis with lymphocytic predominance, microcytic hypochromic anemia and mild hypercalcemia. Analysis of ANA test, HIV test, Hepatitis profile and VDRL were negative. TFT within normal reference, and negative TPO-antibodies. Auxiliary laboratory test as CRP, ESR and LDH were elevated. A thyroid ultrasound showed multiple cervical lymph nodes with intense hilar vascularity and a large isoechoic nodularity involving upper, lower and interpolar left thyroid region, measuring 7.4cm-CC x 3.9 cm-AP x 5.3 cm-TRV. FNA biopsy reported unspecific lymphoma. Supplemental excisional lymph node biopsy disclosed pathological diagnosis of a T-cell lymphoma with immunophenotype of Angioimmunoblastic type. Further PET CT and CT scans of head, neck and abdominopelvic area, suggested a large enhancing posteriorly extended neck mass, intimately associated and originating from the left thyroid gland. The diagnosis of a Primary Thyroid Angioimmunoblastic T-cell Lymphoma was established and patient was referred to an Oncology evaluation for staging and management considerations. Discussion Angioimmunoblastic T-cell Lymphoma is a rare form of non-Hodgkin lymphoma arising from the lymphatic system not from the thyroid gland. In addition, a metastatic process in our patient was ruled out, following the definition of primary thyroid lymphoma which exclude direct malignant invasion to the thyroid gland. According to our literature revision, no cases of such pathology have yet been reported. We consider that our case poses a unique etiological manifestation with extraordinary clinical significance worthy to be the first one communicated in order to diversify diagnostic approach of unexpected manifestations of a thyroid diseases.