<p><strong>In patients with AIP, clinicians should perform additional testing. (<em>Expert Opinion</em>)</strong></p>
Discussion
Discussion
<p>AIP describes lesions with greater architectural complexity and/or cytologic atypia than would be expected in HGPIN but lacking definitive criteria for the diagnosis of intraductal carcinoma (IDC-P).<sup>278-282</sup> AIP encompasses many of the lesions formerly designated cribriform HGPIN, exhibiting loose cribriform architecture with moderate cytologic atypia, but lacking marked pleomorphism or necrosis.<sup>278, 279</sup> AIP, like IDC-P, is usually seen in the context of GG2+ cancer, but uncommonly, may be seen as a sole finding on biopsy or in association with GG1 cancer only. Although there are no prospective studies or those with extended follow-up, available data suggest a close association with unsampled IDC-P<sup>280, 282</sup> and similar adverse pathologic characteristics as IDC-P in patients who went onto radical prostatectomy.<sup>281, 282</sup> Given these associations, a diagnosis of AIP as either the sole finding or together with GG1 cancer only warrants additional testing, which may include early repeat systematic needle biopsy or MRI +/- targeted biopsy. The timing of additional testing should be based on reassessment of risk and SDM. Patients with a diagnosis of AIP in the setting of other biopsy cores showing clinically significant prostate cancer should be managed in accordance with the definitive carcinoma component. As in the PSA screening setting, the use of SDM is highly recommended given the uncertainty involved.</p>