Case Number : Case 2244 - 18 January 2019 Posted By: Dr. Richard Carr

Masson tumor

Intravascular Papillary Endothelial Hyperplasia (aka Masson´s tumor)

Cystic Lymphangioma with organized trombus.

Thrombosed venous malformation. Unlike this case, Masson's tumore is usually well demarcated.

Some kind of vascular malformation with features of Masson's tumor ( papillary endothelial hyperplasia)

 Considering the age the large vessel might be a venous lake with intravascular Intravascular papillary endothelial hyperplasia (Masson's tumor)

Masson tumor

I thought this case was a little unusual but basically a benign haemangioma or lymphangioma or vascular malformation with a dissecting pattern.

I shared with Raul who raised the possibility of lymphangiomatous KS but I did not do HHV8 in this instance because of the clear cut SMA staining in the larger dilated vessels indicative of an indolent lesion. Nor were there plasma cells or haemosiderin to speak of. Raul mentioned doing C-Myc if the lesion was post radiotherapy.

I also shared it with Chris Fletcher (Boston) who (agreeing with Vincenzo) comments as follows: Looks most like progressive lymphangioma with superimposed thrombus, tho’ prominent pericytes a little unusual.  Certainly benign and unlikely to recur.

Thanks for all the responses, warm regards.