Langerhans cell histiocytosis presenting as an isolated brain tumour: A case report

Figure 1 Brain computed tomography. A and B: Represent the lateral ventricular and basal ganglia levels on non-contrast computed tomography (CT), respectively. An irregularly shaped nodule is observed in the left frontal lobe with large perifocal low-density oedema; C and D: Represent the same level as the former on contrast-enhanced CT. The nodules are significantly enhanced heterogeneously; E and F: Represent the coronal and sagittal views of the contrast-enhanced CT; G and H: Represent the same level as the former, with no abnormalities in the adjacent skull. CT: Computed tomography.

Figure 2 Brain magnetic resonance imaging. A: Axial T1-weighted images (T1WI) show heterogeneous hypo-intensity of the left frontal lobe lesion; B: Axial T2-weighted images (T2WI) show heterogeneously mixed signal of hyperintensity with hypointense areas of the left frontal lobe lesion; C-E: Axial, coronal, and sagittal views of T1WI with contrast agent administration show heterogeneous enhancement of the lesion; F: Sagittal T1WI show no abnormality in the sellar region. T1WI: T1-weighted images; T2WI: T2-weighted images.

Figure 3 ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography. A: Maximum-intensity-projection show a focal ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) uptake lesion in the right maxillary sinus and multiple foci with ¹⁸F-FDG uptake in the bilateral lung field; B-G: Axial and coronal views of the selected positron emission tomography (PET), non-enhanced computed tomography (NE-CT), and fused PET/CT images show the left frontal lesion with ¹⁸F-FDG uptake (SUVmax 9.5, arrowheads); H-J: Axial views of the selected PET, NE-CT, and fused PET/CT images show multiple cysts with peripheral exudation in the upper lobes of bilateral lungs, with slightly increased ¹⁸F-FDG uptake (SUVmax 3.2). MIP: Maximum-intensity-projection; PET: Positron emission tomography; CT: Computed tomography.

Figure 4 High-resolution computed tomography of the lung. Axial, coronal, and sagittal (the left and right lungs, respectively) views of high-resolution computed tomography images show multiple scattered small thick-walled irregular cysts as well as small nodules. A: Axial; B: Coronal; C: Left lungs; D: Right lungs.

Figure 5 Histopathological images. A: The specimen is a greyish brown and greyish dark solid tumour; B: The cut surface is greyish brown and greyish white; C: Histopathological examination reveal mononucleated and multinucleated histocytes with abundant cytoplasm and light staining (haematoxylin and eosin, magnification, × 400).