Case Number : Case 2316 - 2 May 2019 Posted By: Raul Perret

Looks like nodular Fasciitis. How big is it? Is it well circumscribed? Rapid growth? I cant rule out pleomorphic dermal sarcoma (although they usually uglier)

Myxofibrosarcoma?

Agree with Anh, My first thought was Myxofibrosarcoma: pleomorphic, myxoid, curvy linear vessels. Interestingly focally there is almost a hint of herring bone pattern. I don't favor nodular fasciitis but will probably need clinical info (age of patient, how fast it grew) to rule it out.

Myxofibrosarcoma is my first thought.

myxoid dermatofibrosarcoma

Myxofibrosacroma primary or DFSP with transformation to myxofibrosarcoma (considering the upper dermal component).

9 hours ago, John Zhang said:

Agree with Anh, My first thought was Myxofibrosarcoma: pleomorphic, myxoid, curvy linear vessels. Interestingly focally there is almost a hint of herring bone pattern. I don't favor nodular fasciitis but will probably need clinical info (age of patient, how fast it grew) to rule it out.

Agree. AFX could be a diff, but it seems a large mass coming from the deep soft parts.

Myxoinflammatory fibroblastic sarcoma

Good diff, Mona. A poorly inflammatory MIFS could be a possibility, because we can see ganglion like atypical cells and some sternbergoid cell(fig3). But it don't seems me at a glance. Waiting for the diagnosis. 

Good differential. This was a grade 2 myxofibrosarcoma. Note the multinodular architecture and the curvilinear blood vessels that are a key finding for this diagnosis. There are not virocyte-like cells in this case but rather multinucleated "myoid" cells which can be sometimes seen in Mixofibrosarcoma. Thanks for participating 

Nice case! Thanks Raul.