Prostatic Adenocarcinoma
Definition
- Malignant epithelial neoplasm of the prostatic acini and ducts
See Classification/Links in left sidebar for Ductal, Intraductal, Small Cell, Mucinous types
Diagnostic Criteria
- Presence of any one of the following features, even if only focal, is considered diagnostic of prostatic adenocarcinoma (none are required for diagnosis and in real life, it is rather uncommon to have these without obvious carcinoma near by)
- Circumferential perineural invasion
- Glands adjacent to and indenting nerves is not sufficient as a solitary diagnostic criterion
- Partial surrounding of nerve may be used as supportive evidence for a diagnosis of carcinoma
- Glomeruloid formations
- Epithelial proliferation projecting into the gland lumen
- Typically a cribriform tuft with a single attachment to the side of the gland
- Resembles a glomerulus in Bowman’s space
- Mucinous fibroplasia / collagenous micronodules
- Dense nodules of collagen surrounded and encased by epithelium
- Frequently entraps epithelial cells
- Frequently appears to represent organized, hyalinized mucin
- The presence of the following features can also be used to make the diagnosis of carcinoma, but none are specific by themselves and none of them is required
- Generally more than one must be present and the focus must not be explainable as a benign glandular collection
- Nuclear enlargement (moderate) and hyperchromasia large nucleoli
- Nuclei are frequently enlarged, but typically uniform
- Very large or pleomorphic nuclei suggest a non-prostatic primary (or normal seminal vesicle)
- May be seen in acute inflammation, partial atrophy
- Prominent enlarged nucleoli
- Nucleoli >3 μ are very rare outside of carcinoma
- Enlarged nucleoli but <3 μ, while not diagnostic may still be helpful
- Basal cells have prominent but small nucleoli
- Luminal blue (acidic) mucin or dense pink amorphous secretion
- May be seen in adenosis and rarely in partial atrophy
- Luminal crystalloids
- Bright red, sharp corners, rectangular
- May be seen in adenosis
- Do not confuse with fractured corpora amylacea which may have occasional sharp edges
- Sharp luminal border
- Normal glands frequently have an undulating border
- Nuclei consistently lined up basally
- Normal glands usually have nuclei at many levels
- Amphophilic cytoplasm
- Not seen in all carcinomas but helpful when present
- Infiltrative pattern
- A distinct population of glands surrounding or separating benign glands
- Lack of lobularity
- Crowded, haphazard glands
- Immunohistochemical demonstration of complete absence of basal cells can be confirmatory of a diagnosis of carcinoma but must be interpreted with caution (see Supplemental Studies)
- See also:
- Atypical Small Acinar Proliferation (ASAP) – what to do with a small focus of suspicious glands
- Benign prostate patterns that may simulate carcinoma
- Carcinoma patterns that simulate benign prostate
- See Grading at left for criteria relevant to Gleason grading
Robert V Rouse MD
Department of Pathology
Stanford University School of Medicine
Stanford CA 94305-5342
Last update 5/7/15
