Spanish to English Medical Medical (general) Pathology report

The following appears in a pathology report from Argentina:

INFORME HISTOPATOLÓGICO
DESCRIPCIÓN MACROSCÓPICA
Se recibe pap en orina, se procesa y se obtienen extendidos citológicos.
DESCRIPCIÓN MICROSCÓPICA
El material centrifugado muestra células uroteliales con cambios reactivos, células planas y aislados leucocitos.
DIAGNÓSTICO
Orina, muestra citológica: Investigación para células neoplásicos: negativo.
M98200 / P / T.

There is no further context or supporting information.

I am unsure what "pap" refers to here.
I have considered the following:
"papila" (papilla) .
PAP test/smear, which does not appear to fit, based on positioning and the lack of capitalisation.
Prostatic acid phoshatase, although no capitalisation.
"pared anterior prostatico" (anterior wall of the prostate), but no capitalisation.

Can anyone help?