case_images: PMC11785415_01
case_images: Computed tomography of the chest, in both (A) the coronal and (B) the axial planes, reveals an oval nodular lesion (red arrow) measuring approximately 7 cm in the longest axis and 4.5 cm in the shortest axis (on the axial plane), located in the anterior mediastinum. The lesion demonstrates heterogeneous density following the administration of contrast. The images C and D show the resolution of the thymoma.
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case_images: FIG1
case_images: A follow-up chest CT scan performed four months after surgery showed no evidence of tumor recurrence (Figure 1).
case_images: Positron emission tomography (PET): The lesion in the anterior mediastinum (red arrow) demonstrates heterogeneous increased uptake of 18F-FDG, with an SUVmax of 3.81.
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case_images: FIG2
case_images: In addition, a positron emission tomography (PET) scan was performed, revealing a lesion in the anterior mediastinum with heterogeneous glycolytic metabolism and bilateral cervical lymph nodes exhibiting high metabolic activity, without other significant changes (Figure 2).
case_images: Thymoma biopsy. . Image A (Hematoxylin and eosin (HE) stain, 50x magnification): HE staining reveals fibrous tissue infiltrated by a neoplastic process, characterized by small lymphocytes and a few epithelial cells.. Image B (CD5 stain, 50x magnification): CD5 immunohistochemistry highlights the T lymphocytes within the neoplasm, confirming their involvement.. Image C (CAM5.2 stain, 50x magnification): CAM5.2 immunohistochemistry demonstrates the epithelial cells within the neoplasm, indicating the biphasic nature of thymomas.
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case_images: FIG3
case_images: The histological result of the mediastinal mass biopsy became available, confirming the diagnosis of thymoma (Figure 3).
case_images: Bone marrow biopsy. . Image A (Hematoxylin and eosin (HE) stain at 200x magnification): The intertrabecular space contains hematopoietic marrow with noticeable myeloid hyperplasia (increased myeloid precursor cells). There is a leftward deviation in myeloid maturation, meaning there is an overrepresentation of immature myeloid cells. Rare megakaryocytes (large cells responsible for platelet production) are visible.. Image B (HE stain at 200x magnification): Hematopoietic marrow in the intertrabecular space is evident but shows rare erythroid lineage elements (reduced red blood cell precursors). This indicates a potential underrepresentation of erythropoiesis (red blood cell production).. Image C (Glycophorin immunohistochemical staining at 200x magnification): Glycophorin immunohistochemical staining highlights erythroid lineage elements, enabling their clear identification within the marrow. This helps to confirm the presence and distribution of erythroid precursors.
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case_images: FIG4
case_images: The bone marrow biopsy revealed a paucity of hematopoietic marrow, with very few erythroid precursors and reactive changes in the myeloid lineage (Figure 4).