Papillary Intralymphatic Angioendothelioma of the Spleen: A Rare Lymphatic Tumour in the Context of a <I>PIK3CA </I>Mutation

Abstract

Papillary intralymphatic angioendothelioma (PILA) is a locally aggressive, rarely metastasising lymphatic tumour that typically arises within the skin and soft tissues. We report a case of PILA arising within the spleen of a 6-year-old boy with megacephaly-capillary malformation (MCAP/MC-M) syndrome. MCAP/MC-M represents part of the phosphatidylinositol-4,5-biphosphate 3 kinase catalytic subunit alpha (<I>PIK3CA) </I>related overgrowth spectrum (PROS). This is the 6<sup>th</sup> reported case in the literature of a splenic PILA and the 2<sup>nd</sup> known to have occurred in the context of a confirmed <I>PIK3CA </I>mutation. In reporting this case we review prior reports of PILA occurring within the spleen and discuss the potential role of the <I>PIK3CA </I>mutation in the aetiology of the lesion, and note a theoretical application of mammalian target of rapamycin (mTOR) inhibitors as a possible therapeutic strategy.