WHO classification of prostate tumours

The World Health Organisation (WHO) classification of prostate tumours is a commonly used classification system for prostate tumours. It was published in 2016 as part of the  WHO Classification of Tumours of the Urinary System and Male Genital Organs ^1,2 and replaces the previous classification from 2004:

Classification

Epithelial tumours

Glandular neoplasms

• acinar adenocarcinoma

  • atrophic acinar adenocarcinoma

  • pseudohyperplastic acinar adenocarcinoma

  • microcystic acinar adenocarcinoma

  • foamy gland acinar adenocarcinoma

  • mucinous acinar adenocarcinoma

  • signet ring-like cell acinar adenocarcinoma

  • pleomorphic giant cell acinar adenocarcinoma

  • sarcomatoid acinar adenocarcinoma

• prostatic intraepithelial neoplasia - high grade

• intraductal carcinoma

• ductal adenocarcinoma

  • cribriform

  • papillary

  • solid

• urothelial carcinoma

Squamous neoplasms

• adenosquamous carcinoma of the prostate

• squamous cell carcinoma of the prostate

• basal cell carcinoma of the prostate

Neuroendocrine tumours

• adenocarcinoma with neuroendocrine differentiation

• well-differentiated neuroendocrine tumour

• small cell neuroendocrine carcinoma

• large cell neuroendocrine carcinoma

Mesenchymal tumours

• stromal tumour of uncertain malignant potential

• prostatic stromal sarcoma

• leiomyosarcoma of prostate

• rhabdomyosarcoma

• leiomyoma

• angiosarcoma

• synovial sarcoma

• inflammatory myofibroblastic tumour

• osteosarcoma

• undifferentiated pleomorphic sarcoma

• solitary fibrous tumour

• malignant solitary fibrous tumour

• haemangioma

• granular cell tumour

Haematolymphoid tumours

• diffuse large B-cell lymphoma

• chronic lymphocytic leukaemia/small lymphocytic lymphoma

• follicular lymphoma

• mantle cell lymphoma

• acute myeloid leukaemia

• B lymphoblastic leukaemia/lymphoma

Miscellaneous tumours

• cystadenoma

• nephroblastoma

• rhabdoid tumour

• germ cell tumour

• clear cell adenocarcinoma

• melanoma

• paraganglioma

• neuroblastoma

Metastatic tumours

Tumour of the seminal vesicles

Epithelial tumours

• adenocarcinoma

• squamous cell carcinoma

Mixed epithelial and stromal tumours

• cystadenoma

Mesenchymal tumours

• leiomyoma

• schwannoma

• mammary-type myofibroblastoma

• gastrointestinal stromal tumour, NOS

• leiomyosarcoma

• angiosarcoma

• liposarcoma

• solitary fibrous tumour

• haemangiopericytoma

Miscellaneous tumours

• choriocarcinoma

• seminoma

• well-differentiated neuroendocrine tumour/carcinoid tumour

• lymphomas

• Ewing sarcoma

Metastatic tumours

Changes from prior versions

Modifications to the Gleason grading system were incorporated into the new version among those:

• cribriform glands and glomeruloid glands should be graded as Gleason 4

• grading of mucinous carcinoma of the prostate should be according to the growth pattern

Entities and variants

Entities include:

• intraductal carcinoma

Variants include:

• microcystic adenocarcinoma

• pleomorphic giant cell adenocarcinoma

• large cell neuroendocrine carcinoma