Genetical and epigenetical profiling identifies two subgroups of pineal parenchymal tumors of intermediate differentiation (PPTID) with distinct molecular, histological and clinical characteristics

Understanding and Managing Pineal Parenchymal Tumors of Intermediate Differentiation: An In-Depth Exploration from Pathology to Adjuvant Therapies

“…Pineal tumors of intermediate differentiation are characterized by intermediate malignancy between pineocytoma and pineoblastoma [ 4 , 7 ]. Histologically, they are composed of diffuse sheets or large lobules of monomorphic round cells that appear more differentiated than those observed in pineoblastomas.…”

“…In this review, we delve into the intricacies of PPTs, emphasizing the histologic and immunohistochemical nuances that underpin their classification, and consequently their treatment. From the initial characterization by Schild et al in 1993 to their formal inclusion in the WHO classification in 2000, PPTIDs have emerged as a distinct subgroup, encompassing both low and high-grade variants [ 3 , 4 ].…”

Reply: pineal parenchymal tumors of intermediate differentiation: in need of a stringent definition to avoid confusion

“…Indeed, the typing of tumors arising in this region needs to be revisited in a larger effort. In our cohort, we specifically focused on tumors that were, based on the current WHO classification CNS5, compatible with PPTID and had been diagnosed as such before [ 2 ]. A clinically annotated, similarly sized cohort of pineocytoma was not available, hence comparison towards this pole of the classification spectrum is limited.…”

Pineal parenchymal tumors of intermediate differentiation: in need of a stringent definition to avoid confusion. Scientific commentary on ‘Genetical and epigenetical profiling identifies two subgroups of pineal parenchymal tumors of intermediate differentiation (PPTID) with distinct molecular, histological and clinical characteristics’

“…In their recent publication in Acta Neuropathologica, Rahmanzade, et al, described a new subgroup of pineal parenchymal tumor of intermediate differentiation (PPTID), suggested to be referred as 'PPTID-C' [8]. Their interesting study raises a very critical issue regarding the terminology of pineal parenchymal tumors (PPTs): what neoplasm should be named PPTID?…”

“…Taking into consideration these earlier definitions ('transitional' and 'pleomorphic' variants of PPTID) together with the more classic definition of PPTID, Rahmanzade, et al, described a new subgroup of PPTID [8]. This new subgroup, named 'PPTID-C', is mainly characterized by transitional morphology (70%) with large cells, significant NFP immunopositivity, absence of KBTBD4 alteration, and loss of chromosome 13q (60%) (Table 1).…”