Prostatic Adenocarcinoma
Definition
- Malignant epithelial neoplasm of the prostatic acini and ducts
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)
- 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 of 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
Original posting/last update: 6/1/12
