In urologic pathology, atypical small acinar proliferation, is a collection of small prostatic glands, on prostate biopsy, whose significance is uncertain and cannot be determined to be benign or malignant. ASAP, generally, is not considered a pre-malignancy, or a carcinoma in situ; it is an expression of diagnostic uncertainty, and analogous to the diagnosis of ASCUS (atypical squamous cells of undetermined significance) on the Pap test..