Papillary tumor of the pineal region: a single-center experience

Abstract

Papillary tumor of the pineal region (PTPR) is a rare entity. Its clinical presentation is diverse, and establishing an accurate and timely diagnosis may be challenging. Treatment recommendations are based on the evidence level of case series. Recently, several key advances have been made for immunohistochemical characterization, molecular diagnostics, and neurosurgical treatment of PTPR. Here, we describe our single-center experience.

Keywords: papillary neoplasm; papillary tumor of the pineal region.

Fig. 1

MRI of cases 1 to 4. Contrast-enhanced T1-weighted sequence, A, C, E, and G, sagittal view, and T2-weighted sequences, B, D, E, and H, axial view. A and B, In case 1, a well-marginated small lesion appears with only faint contrast enhancement. C and D, In case 2, a contrast-enhancing lesion appears with multiple small cysts. E and F, In case 3, a large intraluminal mass appears with only partial contrast enhancement. G and H, In case 4, a contrast-enhancing mass appears with cystic parts and infiltration in the brain parenchyma and surrounding edema.

Fig. 2

Histology and immunohistochemical analyses. A, Histological sections of cases 1 to 4 highlight morphological patterns (hematoxylin and eosin, scale 200 µm). B, Representative immunohistochemical stainings (top left: pan cytokeratin, top right: glial fibrillary acid protein) and expression of mammalian target of rapamycin pathway (bottom left: phosphor-mammalian target of rapamycin, bottom right: phosphor-S6) appear in the majority of tumor cells of case 3 with phosphatase and tensin homolog missense mutation (scale 200 µm). Complete immunohistochemical staining profiles of cases 1 to 4 are available as Supplementary Table 1 and Supplementary Figure 1.