Reversible dilated cardiomyopathy caused by primary hyperparathyroidism: A case report

Figure 4 Histopathology of the parathyroid adenoma in this patient. A and B: Original magnification 10.0 × and 40 ×. In the tissue of parathyroid adenoma, the structures of main cells and eosinophils are clearly distinguishable on hematoxylin and eosin stained sections, and eosinophils aggregate into clusters, significantly increasing compared to normal parathyroid glands. Orange: Eosinophils, blue: Main cell. The dashed line indicates the boundary between eosinophil clusters and main cells; C and D: Positive precipitates of parathyroid hormone immunohistochemistry (IHC) staining can be seen in the cytoplasm of main cells and eosinophils. Among them, the cytoplasmic positivity intensity of the main cells is high, eosinophil positive particles are mainly distributed at the top of the cells, and negative around the nucleus. Black: Positive staining of main cells, blue: Positive staining of eosinophils. The dashed line indicates the boundary between eosinophil clusters and main cells; E and F: The strong positive result of synaptophysin IHC can be seen in the cytoplasm of the main cells. Some eosinophils are weakly positive, while others are negative. Black: Positive staining of main cells, blue: Positive staining of eosinophils, light blue: Negative eosinophils. The dashed line indicates the boundary between eosinophil clusters and main cells.