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 (1985-1995) 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’ calcifications 5/7

Gross hemorrhage 1/7 Enhancement

Heterogeneous 3/4 Uniform 1/4

CT (7 patients) NECT (3), CECT (3), both (1)

Peripheral ‘exploded’ calcifications 5/7

Gross hemorrhage 1/7 Enhancement

Heterogeneous 3/4 Uniform 1/4

CT (7 patients) NECT (3), CECT (3), both (1)

Peripheral ‘exploded’ calcifications 5/7

Gross hemorrhage 1/7 Enhancement

Heterogeneous 3/4 Uniform 1/4

MR

All patients had MRI T1 heterogeneously hypointense 11/11 T2 heterogeneously hyperintense 11/11 Strong heterogeneous CE

10/11 Uniform enhancement 1/11 Cystic-appearing foci 8/11

MR

T1WI T2WI

MR

T1+CT1+C

Leptomeningeal seeding

T1+C T1+CT1+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’ 1st recurrence → ‘pineoblastoma’ Multiple recurrences Died at age 37y Autopsy diagnosis (1991) → ‘Pineoblastoma with transitional

features and retinoblastomatous differentiation’ Pathology reviewed (2010) → PPTID

T1 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

T1 T2 T1+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