Pineal Parenchymal Tumor of Intermediate Differentiation (PPTID), a Newly-designated Tumor: Pathology and Imaging Spectrum in 11 Cases S. T. Komakula, M. Warmuth-Metz, P. G. Hildenbrand, L. Loevner, R. Hewlett, K. L. Salzman, W. T. Couldwell, C. Lin, A. Osborn University of Utah

Purpose  Delineate the imaging spectrum of PPTID, new tumor entity recognized in 2007  Identify imaging findings that may suggest the preoperative diagnosis of this newly- recognized neoplasm

Materials and Methods  IRB-approved  Case material gathered  Search of radiology database since 2001  Key words: ‘pineal tumor,’ ‘pineal mass,’ ‘pineocytoma,’ ‘pineoblastoma’  Search hard copy teaching files for atypical- appearing pineal tumors ( )  Gathered pathologically-proven cases from other institutions

Materials and Methods  Inclusion criteria  11 cases of pathology-proven PPTIDs  Data collected included  Patient demographics  Presenting symptoms  Radiological findings  Treatment and outcome

Results  Demographics:  Age at presentation = 4.5 – 75 yrs (mean = 23 yrs)  M:F = 7:4  Presenting symptoms  Headache 8/11  Parinaud syndrome 3/11  Gait disturbances 3/11  Other unspecified visual symptoms 2/11  Seizures 1/11

Imaging Findings  General features:  Size =1 - 6 cm (mean = 2.5 cm)  Local parenchymal invasion = 9/11  Well-circumscribed = 2/11  Meningeal dissemination = 2/11

CT (7 patients) NECT (3), CECT (3), both (1)  Peripheral ‘exploded’ calcifications5/7  Gross hemorrhage 1/7  Enhancement  Heterogeneous 3/4  Uniform 1/4

CT (7 patients) NECT (3), CECT (3), both (1)  Peripheral ‘exploded’ calcifications5/7  Gross hemorrhage 1/7  Enhancement  Heterogeneous 3/4  Uniform 1/4

CT (7 patients) NECT (3), CECT (3), both (1)  Peripheral ‘exploded’ calcifications5/7  Gross hemorrhage 1/7  Enhancement  Heterogeneous 3/4  Uniform 1/4

MR  All patients had MRI  T1 heterogeneously hypointense11/11  T2 heterogeneously hyperintense11/11  Strong heterogeneous CE10/11  Uniform enhancement1/11  Cystic-appearing foci 8/11

MR T1WIT2WI

MR T1+C

Leptomeningeal seeding T1+C

MRS  1/11  Elevated choline  Decreased NAA  Lactate doublet

Results: Outcome  Follow up available in 8 patients  Surveillance period = 0.5 – 21years  5 patients tumor free  Tumor recurrence in 3 patients

Tumor recurrence  Partial resection in 1997 (1 year after initial symptoms)  Initial histopathology ‘mixed pineocytoma – pineoblastoma’  Recurrence in 2007  Radiosurgery  Continued growth of tumor  Review of pathology → PPTID  Considering surgery Initial post-op scan 10 years later

Tumor recurrence  Initial diagnosis at 15y → ‘pineal teratoma’  1 st recurrence → ‘pineoblastoma’  Multiple recurrences  Died at age 37y  Autopsy diagnosis (1991) → ‘Pineoblastoma with transitional features and retinoblastomatous differentiation’  Pathology reviewed (2010) → PPTID T1 T2CECT

Discussion: PPTID  WHO 2007: New category, PPTID  Describes tumors intermediate in malignancy between pineocytoma (WHO grade I) and pineoblastoma (WHO grade IV)  WHO grade II-III  ~ 20% of all pineal parenchymal tumors  Usually large, complex pineal masses T1T2T1+C

Macroscopy  Hemorrhage  Necrosis  Local invasion  Craniospinal dissemination

Differential Diagnosis  Pineocytoma  Germinoma  Pineoblastoma  Papillary tumor of the pineal region T1+C

Summary  PPTID should be considered in an older child or adult with an atypical or aggressive- appearing, locally-invasive pineal region mass  Histopathology of tumors initially diagnosed as ‘pineocytoma versus pineoblastoma’ or ‘aggressive pineocytoma’ prior to 2007 may also be reviewed as these may be PPTIDs