Hashimotos Thyroiditis with Coexistent Papillary Carcinoma and Non-hodgkin Lymphoma-thyroid

Two lymphoma histotypes and papillary thyroid carcinoma coexisting on Hashimoto ground: a case report and review of the literature

BACKGROUND

Papillary carcinoma is the most frequent type of thyroid carcinoma, while primary thyroid lymphoma is uncommon disease. The coexistence of these entities has already been described, and the common risk factor is considered Hashimoto thyroiditis. The two most frequent histotypes of primary thyroid lymphoma are diffuse large B-cell and mucosa-associated lymphoid tissue lymphoma, but the coexistence of both with papillary carcinoma is rarely reported.

METHODS

We present a case of a previously healthy 57-years old male with rapidly growing lump on the right side of the neck. Ultrasonography revealed nodules in both thyroid lobes. Fine needle aspiration cytology and pertechnetate scintigraphy were performed. Due to the Bethesda T-5 in the "cold" nodule of the right lobe, surgery with histopathological and immunohistochemistry analysis was indicated.

RESULTS

Histopathological and immunohistochemistry methods confirmed concomitant malignancies in the thyroid gland: diffuse large B-cell lymphoma and papillary carcinoma in the right, and mucosa-associated lymphoid tissue lymphoma in the left lobe with Hashimoto thyroiditis in the remaining tissue. Patient underwent therapy procedures and was without signs of local recurrence or metastatic spread on subsequent follow-up.

CONCLUSIONS

Sudden appearance of the neck mass in patients with Hashimoto thyroiditis should raise suspicion on primary thyroid lymphoma and be promptly taken in the diagnostic workup, including fine needle aspiration cytology. Pathology with immunohistochemistry is crucial for further clinical decision making. Since the standardized protocol in management of these complex patients is missing, personal approach and close collaboration between cytologist, pathologist, surgeon, haematologist and nuclear medicine specialist is essential.

Cytodiagnosis of Primary Thyroid Lymphoma Coincident with Unnoticed Papillary Thyroid Carcinoma: A Case Report and Review of the Literature

Papillary thyroid carcinoma (PTC) is the most common type of thyroid cancer, whereas primary thyroid lymphoma is very rare. Here, we report a case in which a right-sided nodule measuring 4.3 × 2.2 cm was examined using fine-needle aspiration biopsy. This revealed abundant monomorphic non-cohesive large lymphoid cells without thyroid follicular cells, on which basis acytodiagnosis of lymphoma coincident with lymphocytic thyroiditis was made. Subsequent histologic examination revealed CD45−, CD20+, and Bcl-6 + and cytokeratin-, CD3-, CD5-, and CD30-negative tumor cells arranged diffusely in the whole thyroid coexisting with a separate PTC nodule sized 1.3 × 1.0 cm in the right lobe. The key point exemplified by this case is that a cytodiagnosis of this extremely rare coexistence of PTC and lymphoma can be made by adequate sampling of both nodules preoperatively. In our case, only one nodule formation was sampled, and therefore the coexisting PTC was not detected with cytology preoperatively.

Impact of Hashimotoas thyroiditis on clinicopathologic features of papillary thyroid carcinoma associated with infiltration of tumor-infiltrating lymphocytes

The association between Hashimoto's thyroiditis (HT) and papillary thyroid carcinoma (PTC) has been a long and ongoing controversy. In the present study, a total number of 322 patients who underwent thyroidectomies were retrospectively studied, and the impact of HT with the incidence, clinicopathologic features, and presence of CD4+, CD8+ tumor-infiltrating lymphocytes (TILs) in PTC patients were analyzed. We further explored the correlation between CD4+, CD8+ TILs and clinicopathologic features in PTC patients with and without HT. The incidence of HT concurrent with PTC was 42.9%, which was significantly associated with a younger age (P=0.039) and the presence of hyperthyroid (P=0.010). The PTC patients coexistent with HT tended to be more female (P=0.001), with diffuse swelling of the thyroid (P<0.001), decreased TSH (P=0.004), and elevated anti-TgAb (P<0.001) and anti-TPOAb (P<0.001). The tumor size of PTC with HT was smaller (P=0.006) and exhibited more bilateral tumors (P<0.001) and less lymph node metastasis (P=0.016). Furthermore, CD4+ and CD8+ TILs in PTC with HT were significantly higher than without HT (both P<0.001). Both high CD4+ and CD8+ TILs were significantly associated with elevated TSH (P=0.019 and P=0.023, respectively), anti-TgAb (P=0.002 and P=0.001, respectively) and anti-TPOAb (P=0.001 and P=0.003, respectively), and the tumor size was smaller (P=0.017 and P=0.039, respectively) and with less lymph node metastasis (P=0.012 and P<0.001, respectively) in PTC with HT. Our study suggests that HT is significantly associated with PTC, which might be ascribed to infiltration of CD4+, CD8+ TILs.

Mantle Cell Lymphoma in the Thyroid: A Rare Presentation

Background

While 2% of all extranodal Non-Hodgkin Lymphomas present in the thyroid, there exists insufficient data to describe the incidence of mantle cell lymphoma in the thyroid. A case series of 1400 patients revealed that <1% of thyroid lymphomas may be MCL; hence better understanding of the disease course is essential.

Patient Findings

A 65-year-old female was referred for a multinodular goiter. Multiple fine needle aspirations from the dominant right nodule were consistent with Hashimoto's thyroiditis and flow cytometry was negative. Due to progressing dysphagia, she underwent total thyroidectomy.

Summary

Pathology revealed MCL with mantle zone growth pattern in the right thyroid. Flow cytometry showed monoclonal B cells comprising 9% of total cells. The Ki-67 index was 10%. She was diagnosed as having stage IIE MCL and offered conservative management by medical oncology, given that she had no B symptoms.

Conclusion

Though chemotherapy is the treatment of choice in MCL, a subset of patients with low-grade disease may be observed. As in our patient, mantle zone growth pattern and a Ki-67 index < 10% suggest a favorable prognosis. A diagnosis of primary MCL in the thyroid remains rare and staging modalities as well as treatment options continue to evolve.

The Effects of Hashimoto Thyroiditis on Lymph Node Metastases in Unifocal and Multifocal Papillary Thyroid Carcinoma: A Retrospective Chinese Cohort Study

The purpose of this study was to investigate the risk factors for central and lateral neck lymph node metastases in papillary thyroid carcinoma (PTC) and multifocal papillary thyroid carcinoma (MPTC), particularly when associated with Hashimoto thyroiditis (HT).A retrospective analysis of 763 consecutive patients who underwent total thyroidectomy with bilateral central neck dissection in the First Affiliated Hospital, College of Medicine, Zhejiang University between October 2011 and October 2014 was conducted. All patients had formal histological diagnoses of HT. Multivariable logistic regression analysis was performed to identify risk factors of neck lymph node metastases.Our study identified 277 PTC patients with HT and showed comparatively low rates of central lymph node metastases (CLNM) compared with the PTC patients without HT (37.2% versus 54.7%, P < 0.001). There were no statistically significant differences in lateral lymph node metastases (LLNM) (P = 0.656). Neck lymph node metastases were histologically proven in 127 (45.8%) patients with PTC with HT, including 103 CLNM and 24 LLNM. There were no significant differences in LLNM between the MPTC-associated HT and classic MPTC cases; however, a significantly reduced risk of CLNM was observed in the MPTC-associated HT compared with the MPTC cases (35.7% versus 72.4%, respectively, P < 0.001). In the multivariate analysis, HT was identified as an independent alleviating factor for CLNM in all PTC patients (odds ratio, 0.369; 95% confidence interval (CI), 0.261 to 0.521; P < 0.001) and in MPTC patients (odds ratio, 0.227; 95% CI, 0.126-0.406; P < 0.001). A cut-off of thyroid peroxidase antibody >140 IU/mL was established as the most sensitive and specific level for the prediction of MPTC based on receiver operating characteristic curve analyses. Thyroid peroxidase antibody, age, tumor size, and multifocality exhibited the ability to predict CLNM in PTC with HT patients with an area under the curve of 81.1% based on a multivariate model.Hashimoto thyroiditis was associated with increased prevalences of multifocality and capsular invasion. In contrast, HT was associated with a reduced risk of CLNM in PTC and MPTC patients, which indicated a potential protective effect. We found that the prognostic prediction model was applicable for predicting multifocality and CLNM in PTC patients with HT.