Prostatic Adenocarcinoma
Differential Diagnosis
Carcinoma patterns that may be confused with benign prostate
- No need to diagnose as specific variants
- Pseudohyperplastic Carcinoma
- Large glands with abundant eosinophilic cytoplasm, may be confused with hyperplasia
- Branching papillae
- Infiltrative pattern may be missing or difficult to appreciate
| Pseudohyperplastic Carcinoma |
(Benign) Hyperplasia |
| Nuclei line up at base |
Nuclei frequently scattered at all levels |
| Luminal border sharp and smooth usually at least in areas |
Luminal border undulating |
| Lacks lobular pattern |
Lobular grouping |
| Luminal crystalloids or blue mucin very suggestive if present |
Crystalloids and blue mucin absent |
| Large atypical nuclei with large nucleoli |
Bland nuclei |
| No basal cells |
Basal cell markers positive |
| Glands may be densely packed with minimal stroma between |
Stroma clearly seen between glands |
Non-straightforward cases should be resolved with IPOX stains for basal cell markers
- Foamy Gland Carcinoma
- Voluminous xanthomatous cytoplasm
- Usually has sharp luminal border
- May virtually fill gland lumens
- Mucin and lipid stains negative
- Bland, pyknotic nuclei
- Usually basal nuclei but may be located in center of cell
- Common as a minor component of usual carcinoma
- No difference in staining pattern from usual acinar carcinoma
| Foamy Gland Carcinoma |
(Benign) Hyperplasia |
| Usually mixed with usual patterns of carcinoma |
Usually associated with benign glands and ducts |
| Luminal border sharp and smooth |
Luminal border undulating |
| Lacks lobular pattern |
Lobular grouping |
| No basal cells |
Basal cell markers positive |
Non-straightforward cases should be resolved with IPOX stains for basal cell markers
- Atrophic Carcinoma
- Refers to a pre-therapy pattern
- Radiation can also result in an atrophic pattern
- Very little cytoplasm
- Simulates small atrophic glands
- If glands are dilated, see Microcystic Carcinoma
- A subset of atrophic carcinomas express p63 in the malignant cells (Giannico)
- HMW keratin is negative
- Recoginzed by infiltrative pattern, poorly formed glands, stratified, often spindled nuclei
- Appear to do well clinically and should not be Gleason graded
| Atrophic Carcinoma |
Benign Atrophy |
| Infiltrative architecture, too many glands |
Lobular groups, frequently with an associated larger duct |
| Most glands have round contours |
Most glands irregular and angulated |
| Luminal crystalloids or blue mucin very suggestive if present |
Crystalloids and blue mucin absent |
| Large atypical nuclei with large nucleoli but may be compressed by cellular flattening |
Bland nuclei |
| No basal cells |
Basal cell markers positive, but may be decreased |
Non-straightforward cases should be resolved with IPOX stains for basal cell markers
- Microcystic Carcinoma
- Densely packed dilated/cystic glands
- Glands approximately 10x the size of usual acinar carcinoma
| Microcystic Carcinoma |
Benign Ducts |
| Crowded grouping dilated/cystic glands, frequently associated with typical carcinoma |
Scattered large ducts usually associated with small benign acini |
| Luminal border sharp and smooth |
Luminal border undulating |
| Nuclei line up at base |
Nuclei frequently scattered at all levels |
| Luminal crystalloids and blue mucin very suggestive if present |
Crystalloids and blue mucin absent |
| No basal cells |
Basal cell markers positive |
Non-straightforward cases should be resolved with IPOX stains for basal cell markers
- PIN-like and Stratified Carcinoma
- Mimics high grade PIN but lacks basal cells
- May be flat, tufted or micropapillary
- Some may be only two cells deep, simulating normal ducts
| PIN-like Carcinoma |
High Grade PIN |
| Crowded grouping of large ducts/glands |
HG-PIN involves scattered large ducts separated by benign parenchyma |
| No basal cells |
Basal cell markers positive |
| May surround nerves |
No perineural invasion |
Non-straightforward cases should be resolved with IPOX stains for basal cell markers
