While many of the psammoma bodies are shelled out during processing, one particularly intact example is seen here. Nice laminations are evident. The lesion is abutting the dura to the right.
The precise degree of psammomatous calcifications needed to label this as the psammomatous variant is not defined.
However, it is clear that this meningioma is packed with psammoma bodies. The background is that of syncytial meningioma consisting of cells with indistinct cell borders.
The cells between the psammoma bodies form whorls, typical of the syncytial (a.k.a meningotheliomatous appearance).
A smear shows psammoma bodies associated with slightly tapered cells.
The psammomatous variant of meningioma consists of abundant psammoma bodies. Note that the common variants of meningiomas (i.e. syncytial or fibrous) also exhibit psammoma bodies, but not quite as prominent as the psammomatous variant. This variant tends to favor the spinal cord (Prayson).
The exact number of psammoma bodies needed to diagnosis this subtype has not been defined; it is probably not relevant clinically and largely academic since like syncytial, fibrous and psammomatous variants are all categorized as WHO Grade I tumors with similar prognosis.
Fletcher CDM, ed. Diagnostic Histopathology of Tumors. 3rd Ed. Philadelphia, PA: Elsevier; 2007: 1707-1710.
Kumar V, Abbas AK, Fausto N. Robbins and Cotran Pathologic Basis of Disease. 7th Ed. Philadelphia, PA: Elsevier; 2005: 1409-1410
Prayson, RA. Neuropathology: Foundations in Diagnostic Pathology. Philadelphia, PA: Elvesier; 2005: 489-494.
Prayson R, Kleinschmidt-Demasters BK, Cohen ML. Brain Tumors. Consultant Pathology Series New York, NY: Demos Publishing: 2010: 190-2.