Strightforward cytological atypia together with CK7+ favor carcinoma, maybe sarcomatoid? maybe metastic?  
Please expand your panel: CK5, cdx2, AB/PAS, give us more high power photos and add virtual slide for better reviewing of sytological details. Remarkable that some areas are IMFT like (imflammatory myofibroblastic tumor like): epithelioid spindle cells with intermingled lymhocytes (ALK?). Are these epithelioid spindle cells positive for Vimentin?

CK5 and CDx2 are negative.  
I like You idea about inflammatory myofibroblastic tumor.  
ALK1 is noted in 40% of the cases, but smooth muscle actin must be possitive.  
Additional IHQ are coming.

I favour the diagnosis of diffuse mesothelioma, mixed type epitheioid/sarcomatoid. As far as I can see, the tumour seems at least partly to be positive for Calretinin. My diagnosis would gain more plausibility, if the tumour cells were negative for BerEP4 (epithelial membrane antigen), monoclonal CEA, and TTF1, and if the patient had been exposed to asbestos. The asbestos exposure may be difficult to explore; it needs evaluation of the whole professional history of the patient. Was the patient engaged in ship building? Even a short but intense exposure in the far past may be cancerologically relevant.

Unfortunately I have no data about asbestos in this case. Heavy inflamation looks unusual in case of mesothelioma, as negativity of CK5 and WT1.  
Lets wait Ber-EP4 and CEA.

Dear colleaque's, please find new IHQ slides. CEA and ALK-1 looks negative. So, I think we have no enought data for tumor diagnosis. "Atipical" cells are myofibroblasts in origin (SMA+).

Dear colleagues, thanks a lot for Your opinion!

I would also favor mesothelioma. D2-40 stain may be helpful, since a positivity would additinally favor mesotheloma.

Histology and negative CEA are well compatible with mesothelioma. To strengthen the diagnosis negative BerEP4-Reaction is necessary. Calretinin-positivity is also expected in mesothelioma and therefore a valuable diagnostic tool. TTF1 is necessary to exclude "pseudomesothelioma". SMA is relatively non-specific, as de-differentiated mesenchymal cells are positive in many tumours. It is a pity, that you do not know anything about the professional history of the patient. In Germany this would be in the interest of the patient and his relatives, as they may get a compensation from the professional association.

Too late dear coleaques for dicusions, patient are dead, and I am waiting results of autopsy.

Dear coleagues, autopsy matherial show clear mesothelioma, please find last 3 images.

Final diagnosis: epithelioid mesothelioma with spreading to heart and mts at liver.  
Case completed.