Prostatic Signet Ring Adenocarcinoma
Definition
- Primary prostatic adenocarcinoma with a prominent population of signet ring cells
Diagnostic Criteria
- No agreement on percent of signet ring cells required for this diagnosis
- 5-50% have been described in the literature
- Nucleus is displaced and indented by clear mucin filled vacuole
- Vacuole must be positive on mucin stain
- Mucin-negative vacuolated "signet ring cell-like" adenocarcinoma is more common
- May be included in many studies
- These are usually high grade also
- Gleason pattern 4, with ragged infiltration and poorly formed glands may simulate scattered signet ring cells
- Cautery in TURP chips may cause stromal cell vacuoles
- Infiltration pattern may be as single cells up to sheets
- Rarely associated with mucinous carcinoma
- Gleason pattern 5 by definition
- May be associated with other patterns, usually 4 or 5
- Poor response to therapy and poor prognosis
- PSA, PAP positive
- Urothelial and non-prostatic origin must be excluded
- Mucinous urothelial carcinoma
- HMWCK positive and CK7/20 double positive in most cases
- PSA and PAP negative (Osunkoya 2007)
- Some older reports find some positivity
- GI tract adenocarcinoma must be ruled out
- PSA and PAP negative
- CDX2 positive in GI primaries but also reported positive in 30% of signet ring prostate carcinomas (Leite 2008)
- History, endoscopy and imaging are critical
- Mucinous urothelial carcinoma
- Bibliography (for general references see Prostatic Acinar Adenocarcinoma)
- Humphrey, P. A. (2012), Histological variants of prostatic carcinoma and their significance. Histopathology, 60: 59–74.
- Torbenson M, Dhir R, Nangia A, Becich MJ, Kapadia SB. Prostatic carcinoma with signet ring cells: a clinicopathologic and immunohistochemical analysis of 12 cases, with review of the literature. Mod Pathol. 1998 Jun;11(6):552-9.
- Osunkoya AO, Epstein JI. Primary mucin-producing urothelial-type adenocarcinoma of prostate: report of 15 cases. Am J Surg Pathol. 2007 Sep;31(9):1323-9.
- Leite KR, Mitteldorf CA, Srougi M, Dall'oglio MF, Antunes AA, Pontes J Jr, Camara-Lopes LH. Cdx2, cytokeratin 20, thyroid transcription factor 1, and prostate-specific antigen expression in unusual subtypes of prostate cancer. Ann Diagn Pathol. 2008 Aug;12(4):260-6.
- For general diagnostic, grading and staging criteria, see also Prostatic Acinar Adenocarcinoma
Robert V Rouse MD
Department of Pathology
Stanford University School of Medicine
Stanford CA 94305-5342
Original posting/updates: 6/1/12
