Case Number : Case 1412- 20 November Posted By: Guest

I see a deep pleomorphic mesenchymal neoplasm with angiosarcomatous, osteosarcomatous and lipomatous features. Thinking of anciently called malignant mesenchymoma that represents an specific sarcoma with malignant heterologous differentiation, maybe in this case a dedifferentiated liposarcoma MDM-2 qnd CDK4 could help.

Raul just preceded me !!!!
I think this is dedifferentiated liposarcoma with angiosarcomatous and fibrosarcomatous dedifferentiation (epithelioid angiosarcoma like, sclerosing epithelioid fibrosarcoma like and MFH like areas)

Sorry Mona but apparently I was quicker with the keyboard, at least we agree with the diagnosis! haha

[color=#1C2837][font=arial, verdana, tahoma, sans-serif][size=4]Dedifferentiated liposarcoma, [/size][/font][/color]to be confirmed by[color=#1C2837][font=arial, verdana, tahoma, sans-serif][size=4] MDM2. [/size][/font][/color]

Agree, dedifferentiated liposarcoma with heterologous elements like osteosarcoma and MFH.

Agree

Well done Raul and colleagues. In fact the dermpathpro team must have been feeling very generous as all the images were given to you in one group. The majority of the tumour was either highly malignant appearing (undifferentiated giant cell tumour pattern with interstitial haemorrhage) and osteosarcoma but no angiosarcoma morphologically for me (although I confess I did not do any immunos or any other studies in fact) that readily catches the eye. However roughly 50% of the lesion was relatively hypocellular and evenly cellular as seen in part in the top two images with scattered hyperchromatic nuclei. The significance of the relatively small focus of obvious liposarcoma (nice with lipoblasts) was overlooked by the colleagues who kindly shared this case with me. I remember Chris Fletcher teaching that relatively few soft tissue lesions leave fat in the tumour (rather than pushing it aside e.g. DFSP) so that whenever you see a fat component in a soft tissue lesion consider the possibility of an adipocytic histogenesis. I therefore agree this case is compatible with a [b]predominantly sclerosing well differentiated liposarcoma with dedifferentiation[/b]. In the UK patients with proper "soft tissue" sarcomas such as this are automatically referred to centres and a soft tissue expert pathologist will also automatically request slides and tissue blocks for review. Since the patient was not from my own geographic area I was content with making an H&E diagnosis and not delay the referral process so I do not know if additional molecular work-up was undertaken. On another note any benign to highly malignant tumour of pretty much any histogenesis that has interstitial haemorrhage may (in addition to having (often malignant) tumour giant cells) attract reactive osteoclast-type giant cells (that are characterised by bland clustered nuclei similar to foreign body type giant cells but have characteristic red/purple as opposed to pale pink cytoplasm).

On another note: We have enjoyed a wonderful ISDP meeting in New Dehli - many thanks to the organising committee and sincere apologies for running over on my presentation. A good case to appear on dermpathpro sometime in the future. It was nice to meet a few dermpath pro "fans" at the meeting.