Contributed by Rajmohan Murali1,2, Wayne I. Jones1,2, Jenny Ma Wyatt1
1 Department of Anatomical Pathology Nepean Hospital, Penrith, Australia
2Department of Tissue Pathology, Institute of Clinical Pathology and Medical Research, Westmead Hospital, Westmead, NSW 2145, Australia
Published on line in April 2007
An otherwise well 57-year-old man presented with a 6 month history of worsening headaches, hearing difficulties and personality changes. No sensory or motor deficits were found on clinical examination. Computed tomography (CT) and magnetic resonance (MR) imaging showed a dural-based, contrast-enhancing, lobulated left parasagittal mass, associated with mass effect. A clinicoradiologic diagnosis of meningioma was made.
Craniotomy revealed a vascular tumor arising from the falx cerebri and sagittal sinus, showing extensive dural attachment. Two fragments of soft, red tumor tissue, measuring 3mm and 5mm in maximal dimension, were removed for intra-operative diagnosis, following which the tumor was resected.
Air-dried smears of fresh tumor tissue stained with Diff Quik were moderately cellular and showed several cohesive groups of cells as well as detached small groups of cells in a bloody background. Scattered intact single cells and a few stripped nuclei were also present. The cell groups were often too thick to permit interpretation, except at their edges where thin strips of cells extended out and revealed cytologic detail. Capillary-sized vessels were prominent within the cell groups and streaming away from them, with some vessels being closely associated with the tumor cells. (Fig 1A) The cells possessed moderate amounts of often poorly-defined, pale, filmy and/or foamy cytoplasm; the cytoplasmic vacuolation was inapparent on wet-fixed, hematoxylin & eosin-stained smears. (Fig 1B, inset) Their nuclei were round-to-oval and hyperchromatic with coarse chromatin. (Fig 1B) Occasional nuclei exhibited grooves and folds. Appreciable nuclear pleomorphism was present, and some bizarre stripped nuclei were seen. (Fig. 1B, inset) The frozen sections showed a cellular, predominantly solid-appearing tumor composed of sheets of cells with amphophilic cytoplasm and moderately pleomorphic nuclei. Occasional thick-walled vessels were present. No mitotic activity or necrosis was seen. (Fig 2A)
The resected specimen consisted of a congested, grey-red nodule measuring 40x35x20mm. Dura was intimately adherent to part of the surface of the nodule. The cut surface showed a hemorrhagic, spongy and microcystic appearance. Histologically, the tumor was composed of sheets of round-to-oval cells exhibiting moderate nuclear pleomorphism, in a richly vascular background containing numerous capillary-sized vessels as well as larger feeder vessels. The cells contained moderate amounts of clear or vacuolated cytoplasm. (Fig 2B) The tumor cells were negative for cytokeratins and epithelial membrane antigen (EMA), and for CD31, which highlighted the rich background vasculature.