There's
NeoOffice. If this doesn't work, let me know. I have 3.1.2 Patch 4. Opens .docx. From there you can export a PDF.
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Just a note that PDFs saved from OSX are generally the worst PDFs for print. They are RGB, generally don't have fonts embedded and are usually 72dpi (if graphics are included). That's because the OS is making them simply for viewing, general printing from the Mac. Not for publication.
I realize that that's being nitpicky as this is probably just a document containing text, but you don't know how many OSX PDFs I've gotten from people who thought everything was camera ready, but wasn't.