An eight-year-old male presented with a mass in the right anterior neck that had been apparent for one week. Upon physical examination, blood pressure was recorded as 100/65 mmHg, heart rate was 80 beats per min, respiratory rate was 20 breaths per min and temperature was 36.1°C. A mass measuring ~4.0 cm in size, which caused difficulty in swallowing, was identified in the right anterior neck. The laboratory test results demonstrated a normal blood count and serum biochemistry, as well as normal levels of electrolytes and carcinoembryonic antigen. In addition, the test results for Epstein-Barr virus (EBV) viral capsid antigens immunoglobulin (Ig)M and IgG, human immunodeficiency virus (HIV) and hepatitis C virus antibodies, hepatitis B antigen and syphilis were negative. Furthermore, the thyroid hormone test results were as follows: Free thyroxine (FT) 4 levels of 11.8 pmol/l (normal range, 9–25 pmol/l); FT3 levels of 4.2 pmol/l (normal range, 3–9 pmol/l); thyroid-stimulating hormone levels of 0.720 μIU/ml (normal range, 0.34–5.60 μIU/ml); anti-thyroglobulin levels of 20 IU/ml (normal range, <115 IU/ml); and anti-thyroid peroxidase levels of 25 IU/ml (normal range, <34 IU/ml). The patient had no significant past medical or family history of disease. A B-mode ultrasound examination revealed a mass measuring 4.0×3.0×2.5 cm in the right lobe of the thyroid (), however, the lymph nodes surrounding the mass were normal (). The patient underwent a right lobe and isthmus thyroidectomy whereby two lymph nodes were excised simultaneously. Following the surgery, positron emission tomography-computed tomography scans showed normal metabolism in the left lobe of the thyroid and other parts of the body (). The patient’s bone marrow cytology was also normal, however, histological examination revealed diffuse infiltration of atypical lymphocytes and the observation of residual thyroid follicles and necrosis (). In addition, under low magnification, the ‘starry sky’ histology was observed in certain areas (). The atypical lymphocytes were medium-sized and consistent, with centrally located nuclei of irregular shape, displaying dispersed and deep basophilic chromatin and scanty cytoplasm. Additionally, certain neoplastic cells were visible, while varying numbers of nucleoli and apoptosis and mitosis were observed. Benign tissue cells engulfing apoptotic bodies were also observed under high magnification (), however, the isthmus of the thyroid was not infiltrated by the neoplastic cells. No reactive lymphocyte infiltration or fibrosis was identified in the stroma of the thyroid, and no oxyphilic change or squamous metaplasia was observed in the epithelial cells of the background thyroid tissues (). The only change in the two lymph nodes that were simultaneously excised, was the presence of reactive hyperplasia of the lymphoid follicles (). Immunohistochemical staining was then performed with the primary antibodies shown in (Zymed Corporation, Inc., San Francisco, CA, USA; Santa Cruz Biotechnology, Inc., Santa Cruz, CA, USA). The results showed that the neoplastic cells were diffusely positive for cluster of differentiation (CD)20 () and CD10 (), marginally positive for CD38, CD43 and B-cell lymphoma (Bcl)-6, but negative for Bcl-2 and terminal deoxynucleotidyl transferase (TDT). In addition, CD3 and CD5 stained the background T cells, and the Ki-67 proliferation index was >95% (). Analysis using an EBV-encoded small RNA (EBER) digoxin-labeled probe (PanPath B.V., Budel, Netherlands) was performed and revealed a negative result (), however, positive nuclei were observed in the nasopharyngeal carcinoma tissue, which was used as the positive control (). Analysis using the C-MYC break-apart detection probe (Guangzhou LBP Medical Science Technology Co., Ltd., Guangzhou, China) was also performed and the results revealed that ~90% of the neoplastic cells exhibited red and green signal separation, which indicated that chromosome breakage and translocation of the MYC gene had occurred in the neoplastic cells (). Immunoglobulin gene rearrangement assays were performed according to instructions of the Biomed-2 Polymerase Chain Reaction kit (Invivoscribe technologies, Inc., San Diego, CA, USA), followed by capillary electrophoresis, which was analyzed using Genemarker® v1.5. software (SoftGenetics, LLC, State College, PA, USA). Positive gene arrangements of IgH and IgK were observed in the tumor tissues, however, no positive gene rearrangements were observed for IgL (). Consequently, the patient was diagnosed with primary BL of the thyroid and underwent alternate R-B-NHL-BFM-90-A and R-B-NHL-BFM-90-B treatment, for four cycles each. The two regimens, including the dose and duration of chemotherapy, are described in . After almost four years of follow-up, the patient appears well and remains free of disease.
A 49-year-old woman with a history of Hashimoto’s thyroiditis presented with a rapidly growing neck mass and upper airway compression symptoms. No B symptoms were present. The hematological test showed a white blood cell count within the normal range (51.5 × 102/μL). Interleukin-2 receptor (801 U/mL) and lactate dehydrogenase (228 U/L) levels were elevated, although serum thyroxine and thyroid-stimulating hormone levels were within their normal ranges. An elevated thyroid peroxidase antibody of 271.4 IU/mL was detected. Ultrasonography revealed a mass measuring 2.0 × 1.0 × 1.0 cm in the right lobe of the thyroid; the border of the nodule was indistinct. The patient underwent a right thyroidectomy after a core needle biopsy revealed a diffuse large B-cell lymphoma. Following the final histological diagnosis of primary thyroid BL, the patient received rituximab, cyclosphosphamide, doxorubicin, vincristine, and prednisone for 2 weeks, as well as rituximab, hyperfractionated cyclophosphamide, vincristine, doxorubicin, and dexamethasone including prophylactic intrathecal methotrexate for 3 months. Adjuvant treatments involving 22 cycles of linear accelerator (LINAC) therapy, 40 Gy each, were administered after the chemotherapy. Thirty months after the initial diagnosis, the patient had no evidence of recurrent disease.\nThe tumor cells were composed of round, intermediate-sized lymphoid cells admixed with scattered tingible body macrophages imparting a “starry sky” appearance (Fig. ). The nuclei were uniform and round-to-oval-shaped. The chromatin was coarsely clumped and had medium-sized paracentral nucleoli, while the cytoplasm was basophilic. Mitotic figures (12 per high-power field) were identified; there was no coagulative necrosis, although extrathyroidal extension was observed. Hashimoto’s thyroiditis was identified in the non-tumoral thyroid tissue.\nDiffuse membranous immunostaining for CD10, CD20, and CD79α, as well as diffuse nuclear staining for MUM-1 (Fig. a) and p16 (Fig. b), were noted in the tumor cells. The expression of MDM2 was focal and confined to the tumor cell nuclei (Fig. c), although the cells were negative for Bcl-2, Bcl-6, and p53. The Ki-67 labeling index exceeded 90% (Fig. ). The EBER in situ hybridization test was negative (Fig. ). Ninety-six percent of the tumor cells were found to have MYC/IgH gene fusion as determined by FISH (Fig. ).\nThe clinicopathological features of 21 thyroid BLs are summarized in Table . The median age at diagnosis was 39.3 years with a male-to-female ratio of 13/8. The majority (94.4%) of these patients presented with a thyroid mass; patients also presented with a rapidly growing nodule (66.7%), dyspnea (61.1%), dysphagia (16.7%), and thyrotoxicosis (5.6%). Four of the 14 described patients (28.6%) showed B symptoms (e.g., systematic symptoms of fever, night sweats, or weight loss). None of the reported patients presented with immunosuppressive conditions or the endemic form of BL. Regarding the treatment modalities, all of the 20 patients for whom data were available (data for 1 were missing) received multidrug chemotherapy regimens; 12 received chemotherapy only, 7 received chemotherapy with combined surgery, and 1 was administered chemotherapy combined with surgery and adjuvant radiotherapy (LINAC).\nFive of 7 patients with thyroid BL (71.4%) had morphologic evidence of Hashimoto’s thyroiditis. Regarding immunohistochemical features, all patients who were tested for CD10 (n = 14), CD20 (n = 18), and CD79a (n = 5) were positive for these respective proteins. IgM was positive in the lone patient who was tested. Additional factors measured are shown in Table . The Ki-67 labeling index exceeded 90% in all 19 patients for whom such staining was performed. We demonstrated that our patient had focal immunoreactivity for MDM2, but none of the other patients had been tested for this protein. All 12 patients who were tested for EBER in situ hybridization showed negative results, and flow cytometry immunophenotyping demonstrated CD10-positive monotypic B-cell populations in all 5 tested patients; moreover, MYC gene translocation was detected using FISH in all 12 patients whose samples were tested.\nOf 19 patients with available clinical outcome data, 14 (73.7%) were alive with complete remission, 1 (5.3%) was alive with persistent disease, and 4 (21.1%) died of the disease. Three of the 19 patients lacked follow-up data; hence, the median follow-up of the 16 remaining patients was 46.5 months (range, 0.5–361 months). Kaplan-Meier survival analysis showed that the 12- and 60-month overall survival rates were 87.5 and 70.7%, respectively (Fig. ).