[744] Atypical Prostatic Ductal Lesions (APDL) Presenting as Small Prostatic Urethral Polyps: A Clinicopathologic Study of 7 Cases and Documentation of a Unique form of Prostatic Ductal Neoplasia Warranting Active Surveillance.

Chandrakanth Annaiah, Bonnie L Balzer, Rugvedita S Parakh, Loren P Herrera, Komal Arora, Daniel J Luthringer, Mahul B Amin. Cedars-Sinai Medical Center, Los Angeles, CA

Background: Prostatic ductal carcinoma (PDCa) involves the prostate as: a) as papillary transition zone lesions with obstructive symptoms in transurethral (TURP) specimens, or b) as diffuse proliferations in the parenchyma with elevated PSA, abnormal rectal exam in needle biopsies (NBx). It is an aggressive variant of prostatic cancer (PCa) when pure in histology and when it is occurs concurrently with acinar PCa, it is associated with high stage disease.
Design: We describe 7 cases of APDLs that presented with hematuria and as small urethral polyps. At the time of diagnosis, due to restriction to suburethral tissue, active surveillance with repeat TURP and multiple peripheral zone NBxs was recommended to document further extent of disease.
Results: Patients presented with hematuria, the mean age was 73 (64-83) yrs. The lesions occurred in the prostatic urethra & varied in size from 0.2 to 0.9 (mean 0.5) cm. All lesions had a large glandular tubuolopapillary pattern with intraductal growth. Four cases had a component of ductal histology without basal cells (invasive growth); three were exclusively intraductal. These findings were supported by reactivity pattern of basal cell markers (p63 & HMCK). The cells were predominantly elongated with prominent nucleoli & showed pseudostratification. All cases strongly expressed racemase & prostatic lineage markers (PSA, PSAP, PSMA). CDX2 & PAX2 were negative. On follow up [6 cases – 7-72 (mean 30.5) months] invasive PDCa or acinar PCa was diagnosed in peripheral zone NBxs (2 cases) & no evidence of neoplasia was detected in repeat TURP or NBxs (3 cases); 1 case had a 1 cm APDL in a repeat urethral biopsy with no further disease progression in 30 months.
Conclusions: 1) APDL may present as small urethral polyps raising the differential diagnosis of villous adenoma and nephrogenic adenoma. 2) There are only 2 papers in the literature of similar cases whereby, diagnostic criteria employed designate them as PDCa, a diagnosis which generally evokes radical treatment due to implied poor prognosis. 3) Our study describes a unique form of prostatic ductal neoplasia, distinct from cancers more typically detected in TURP or NBxs, in which there is prominent intraductal growth. 4) Follow up data showing lack of involvement of the prostate gland or significant disease progression (67%), suggesting that these patients may be candidates for active surveillance, a treatment modality conventionally not associated with PDCa.
Category: Genitourinary (including renal tumors)

Monday, February 28, 2011 1:00 PM

Poster Session II # 157, Monday Afternoon

 

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