Case of prostate stromal tumour of uncertain malignant potential where positron emission tomography with 18F-fluorodeoxyglucose was useful for surgical planning

Primary mesenchymal tumors of the prostate:18F FDG PET/CT findings

BACKGROUND

Primary mesenchymal tumors of the prostate are very rare, and there is no systematic report on fluorine-18-fluorodeoxyglucose positron emission tomography (18F-FDG PET/CT). The aim of this research was to characterize mesenchymal tumors of the prostate on 18F-FDG PET/CT.

RESULTS

We included 13 patients with pathologically confirmed mesenchymal neoplasms of the prostate. The location, size, maximum standardized uptake value (SUVmax), metabolic tumor volume (MTV), total glycolysis of the lesion (TLG), pathologic findings, and available imaging study of the tumors were reviewed. Of the 13 patients (median age, 38 years; ranged from 13 to 74 years), the mean size of the tumors was 8.8 cm in diameter ranged from 5 to 16.1 cm. SUVmax ranged from 3.1 to 17.6 (mean 9.5), MTV ranged from 4.9 to 398 cm3 (mean 109 cm3) and TLG ranged from 21.3 to 1216 g (mean 96 g). The seminal vesicles, rectum, and bladder are the most commonly affected sites of invasion, while metastasis typically occurs in the bones, lungs, and lymph nodes.

CONCLUSIONS

Mesenchymal tumors of the prostate revealed large sizes and high SUVmax, MTV and TLG levels on 18F-FDG PET/CT. 18F-FDG PET/CT may be useful for accurate diagnosis, staging, and restaging, which plays an important role in the management of subsequent plans.

Prostatic stromal tumor of uncertain malignant potential: a case report and literature review

Prostatic stromal tumors, encompassing prostatic sarcoma and stromal tumors of uncertain malignant potential (STUMP), represent an exceedingly rare category of prostatic diseases, with a prevalence of less than 1%. We present a rare case involving a man in his early 40s diagnosed with STUMP. Despite presenting with normal prostate-specific antigen (PSA) concentrations, the patient experienced persistent dysuria and gross hematuria for >7 months, leading to an initial misdiagnosis of benign prostatic hyperplasia. Persistent symptoms prompted further investigation, with magnetic resonance imaging (MRI) revealing a suspicious lesion on the left side of the prostate, initially thought to be malignant. Transrectal prostatic biopsy subsequently confirmed the presence of mucinous liposarcoma, with no medical history of diabetes, coronary heart disease, or hypertension. The treatment approach comprised robot-assisted laparoscopic radical prostatectomy, culminating in a postoperative pathological definitive diagnosis of STUMP. This case underscores the indispensable role of early MRI in the diagnostic process, highlighting the necessity of detailed pathological examination for a conclusive diagnosis. Our report aims to illuminate the diagnostic challenges and potential treatment pathways for STUMP, emphasizing its consideration in the differential diagnosis of prostatic tumors to advance clinical outcomes in this rare but important condition.

Prostatic stromal tumour of uncertain malignant potential treated with robotic-assisted radical prostatectomy: medium-term oncological and functional outcome of two cases

Stromal tumour of uncertain malignant potential (STUMP) is a rare tumour of the prostate with variable and unpredictable risk and clinical progression. There is no clear consensus on how it should be managed. We describe two cases of patients who presented to their general practitioners with raised prostate-specific antigen in one instance and an abnormal digital rectal examination in the other. Biopsies were carried out and a diagnosis of STUMP was made. Both cases were managed with robot-assisted radical prostatectomy and after 4.8 years of follow-up, there has not been any recurrence. This is the first reported UK case in which STUMP has been successfully managed with robotic surgery with excellent medium-term results. Radical prostatectomy can be used to treat STUMP tumour with good oncological and functional outcomes.

A case of incidental STUMP discovery in a patient with concurrent prostatic adenocarcinoma

Stromal tumours of the prostate are exceedingly rare, often presenting in patients in their fifth decade of life. They are classified as either stromal sarcomas, or stromal tumours of uncertain malignant potential (STUMP), the latter of which is known to have diverse clinical behaviour and thus surgical excision is often warranted. We present a case of a 71-year-old male, initially worked up by his family doctor due to mild obstructive voiding symptoms. Following a more thorough urologic workup, including a prostate biopsy, he was found to have a markedly elevated prostate specific antigen and positive cores on prostate biopsy demonstrating prostatic adenocarcinoma. The decision was made to treat with retropubic radical prostatectomy and bilateral pelvic lymph node dissection. Resulting pathology showed concurrent prostatic adenocarcinoma in addition to STUMP. The patient continues to be followed by oncology as well as a sarcoma specialist due to the unique nature of his case.