Show the entry category, that´s it
If I'm following you correctly, it should be as simple as this:

&lt;span class="catNoticia"&gt;
    {% if blog.myCategoryFieldHandle|length %}
        &lt;ul&gt;
            {% for category in blog.myCategoryFieldHandle %}
                &lt;li&gt;{{ category.title }}
            {% endfor %}
        &lt;/ul&gt;
    {% endif %}
&lt;/span&gt;