<?php
$html = '
<table>
<td>Any html <span>code</span> this</td>
<td class="нужно получить меня">Any html <span>code</span> this</td>
</tr>
<tr>
<td>Any html <span>code</span> this</td>
<td class="нужно получить меня">Any html <span>code</span> this</td>
</tr>
<tr>
<td>Any html <span>code</span> this</td>
<td class="нужно получить меня">Any html <span>code</span> this</td>
</tr>
</table>
';
$pat = '/<td.*?>.*?<\/td.*?>/si';
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