This is a rare group of malignancies which may arise in the prostate.
Tumours of Prostatic Stroma
The stroma of the prostate can give rise to two unique mesenchymal malignancies.
Stromal Tumour of Uncertain Malignant Potential (STUMP)
This is considered a malignant tumour due to its ability to invade throughout the prostate gland, invade adjacent structures and locally recur. Metastasis is rare. They may resemble phyllodes tumour of the breast with a hypercellular stromal component.
Sarcoma of the prostate stroma is a poorly understood and rare disease. It may resemble a phyllodes tumour or be similar to leiomyosarcoma. Metastasis can occur.
Other Mesenchymal Tumours
This is the most common type of prostate sarcoma. It is similar in appearance to leiomyosarcoma elsewhere. It frequently recurs locally and metastasises to the lungs.
This tumour is notable for being the most common sarcoma of the prostate in childhood. It has a relatively good prognosis if localised. Patients who present with metastatic disease have a poor prognosis.
Most other types of sarcoma have been reported in the prostate but only a few cases exist.
Lymphomas rarely occur in or involve the prostate gland. Most cases are non-Hodgkins (DLBCL).
Primary prostatic melanoma is very rare.
Clear Cell Adenocarcinoma
This tumour resembles those from the female genital tract and is thought to arise from the prostatic urethra or from Mullerian duct remnants.
Metastatic tumours to the prostate are very rare. The lung is the most common primary. Germ cell tumours may also metastasise to the prostate in very rare occasions.