Brain Pathology Case of the Month - December 2018

Contributed by Josť Pimentel, MD, PhD1,3,4, Ana Afonso, MD1, Rafael Roque, MD3, Jo„o Paulo Farias, MD2
1Department of Pathology, and 2Neurosurgery, Hospital Cuf Descobertas, Lisbon; 3Laboratory of Neuropathology,
      Department of Neurology, Hospital de Santa Maria (CHLN), Lisbon; 4Faculdade de Medicina, Universidade de Lisboa, Lisbon


CLINICAL HISTORY

An 82-year old male presented with a 3 month long progressive cognitive deterioration, particularly regarding temporo-spatial orientation and short term memory. Previous medical history included colorectal carcinoma with liver metastases, prostatic carcinoma, type 2 DM and arterial hypertension. No focal neurological signs were elicited, and a MRI scan (Fig. 1a) showed an extra-axial fronto-basal tumor, with heterogenous contrast enhancement and dural tail sign (not seen in the image). A large cyst between the lesion and the cortex could also be seen. A frontal craniotomy with total excision of a non-infiltrative, dural-adherent mass was performed. MICROSCOPIC EXAMINATION

H&E sections disclosed a high cellular and vascularized tumor where pigmented cells could easily be seen (Fig. 1b). These cells were localized, as much near the vessels as far from them, in the core of the tumor parenchyma, and indistinguishable from neoplastic elements (Fig. 1c). Neoplastic cells were mainly spindled or oval with sheeting arrangements and intermingle with pigmented cells (Fig. 1d). Focally, nests of neoplastic cell with intervening stroma containing also pigmented cells could be seen (Fig 1e). No nuclear pseudo-inclusions, pseudo-syncytial areas, whorls or psammoma bodies were elicited. Pigment became evident with Perls staining (Fig. 1f) but not with Fontana-Masson. Neoplastic cells displayed extensive reactivity for EMA (Fig. 1g), vimentin (Fig. 1h) and progesterone receptor (Fig. 1i), but negativity for S100, Melan A (Fig. 1j) and HMB-45. There were no anaplastic features, including high mitotic or proliferative (Ki67) indexes. What is your diagnosis?

FINAL DIAGNOSIS


International Society of Neuropathology