Inflammatory infiltrates in parathyroid tumors

Tuberculous granulomatous inflammation of parathyroid adenoma manifested as primary hyperparathyroidism: A case report and a review of the literature

Tuberculosis of the thyroid gland is rare, and tuberculous granulomatous inflammation of the parathyroid glands is even rarer. The present study reports a rare case of primary hyperparathyroidism caused by tuberculous granulomatous inflammation. A 58-year-old female patient presented with generalized body pain persisting for 1 year. She had a history of recurrent renal stones (>20 times) and an incidental finding of multinodular goiter involving the parathyroid on neck ultrasound. A blood analysis revealed elevated levels of serum calcium (11.26 mg/dl) and parathyroid hormone (154.7 pg/ml). The patient underwent the resection of the affected left thyroid lobe under general anesthesia. A histopathological examination revealed parathyroid adenoma with caseating granulomatous inflammation involving the adenoma with focal lymphocytic thyroiditis of the left thyroid gland. Although granulomatous parathyroid disease with parathyroid adenoma causing hypercalcemia is an extremely rare event, it can occur. The treatment of choice is surgical resection.

Immunocyte density in parathyroid carcinoma is correlated with disease relapse

PURPOSE

Parathyroid carcinoma (PC) is an endocrine malignancy with a poor prognosis. The tumour immune microenvironment is a critical factor influencing the outcomes of multiple cancer types. However, knowledge of the immune microenvironment in PC remains limited.

METHODS

The intratumoural density of immunocytes and the Ki-67 index were evaluated immunohistochemically in 51 PC patient samples and were compared with clinicopathological features and parafibromin staining results. The Kaplan-Meier method and Cox proportional hazards analysis were used to estimate the effects of these variables on clinical outcomes.

RESULTS

Intratumoural immunocyte density was not correlated with age, gender, urolithiasis, or palpation of a neck mass. The Ki-67 index was correlated with the intratumoural density of CD3⁺ cells (P = 0.022) and CD8⁺ cells (P = 0.021) and serum calcium levels (P = 0.022). In the intratumoural area of primary foci, Kaplan-Meier method showed that the risk factors associated with recurrence/metastasis were a low density of CD3⁺ (P = 0.017), CD8⁺ (P = 0.019) and CD45⁺ cells (P = 0.047), a high density of CD163⁺ cells (P = 0.003) and a high Ki-67 index (P = 0.004). Cox regression multivariate analysis revealed that CD163⁺ cell density (hazard ratio (HR) 16.19, 95% confidence interval (CI) 1.99-131.66; P = 0.009) and CD8⁺ cell density (HR 0.13, 95% CI 0.02-0.76, P = 0.024) were independent factors associated with PC relapse.

CONCLUSION

The immune microenvironment is an important factor influencing the relapse of PC. The intratumoural density of CD3⁺, CD8⁺, CD45⁺, and CD163⁺ immunocytes was correlated with disease-free survival (DFS) in patients with PC. Immunotherapy based on T lymphocytes or tumour-associated macrophages may be a promising treatment strategy.

Parathyroid Tumor Microenvironment

Parathyroid tumors are the second most common endocrine neoplasia, and it is almost always associated with hypersecretion of the parathormone (PTH), involved in calcium homeostasis, causing primary hyperparathyroidism (PHPT). Parathyroid neoplasia has a stromal component particularly represented in atypical adenomatous and carcinomatous lesions. Recently, data about the features and the function of the parathyroid tumor microenvironment (TME) have been accumulated. Parathyroid TME includes heterogeneous cells: endothelial cells, myofibroblasts, lymphocytes and macrophages, and mesenchymal stem cells have been identified, each of them presenting a phenotype consistent with tumor-associated cells. Parathyroid tumors overexpress proangiogenic molecules including vascular endothelial growth factor (VEGF-A), fibroblast growth factor-2 (FGF-2), and angiopoietins that promote both recruitment and proliferation of endothelial cell precursors, thus resulting in a microvessel density higher than that detected in normal parathyroid glands. Moreover, parathyroid tumor endocrine cells operate multifaceted interactions with stromal cells, partly mediated by the CXCL12/CXCR4 pathway, while, at present, the immune landscape of parathyroid tumors has just begun to be investigated. Studies about TME in parathyroid adenomas provide an example of the role of TME in benign tumors, whose molecular mechanisms and functions comprehension are limited.