Stromal tumor of uncertain malignant potential of the prostate

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.

Robot-Assisted Extraperitoneal Radical Prostatectomy for Giant Multilocular Prostatic Cystadenoma: A Case Report and Literature Review

A 48-year-old man with a medical history of hypertension and no family history of prostate cancer presented with abdominal distension, lower abdominal pain, and lower urinary symptoms. Physical examination revealed a palpable mass in the lower abdomen, and a digital rectal examination detected a firm mass on the anterior side of the rectum. Laboratory tests showed an elevated PSA level (7.9 ng/mL). Imaging studies indicated a solid mass connected to the prostate's posterior and rectum's anterior walls, along with bladder compression. Transperitoneal biopsy and histological analysis led to a diagnosis of a stromal tumor with uncertain potential malignancy. Considering the absence of apparent malignancy signs and the smooth outer wall of the tumor, the patient underwent, for the first time in the literature, a robot-assisted radical extraperitoneal prostatectomy for complete macroscopic resection. The surgery involved excision of the bulky pelvic mass, preservation of the urethra, and anatomical reconstruction. The postoperative course was uneventful, and we discharged the patient with no complications. The pathological examination documented the diagnosis of multilocular prostatic cystadenoma. Post-surgery follow-up examinations, including PSA levels and imaging scans, showed no signs of tumor recurrence. At the 3-, 6-, and 9-month follow-ups, the patient was asymptomatic and had fully recovered, with no urinary or sexual dysfunction reported.

Magnetic resonance imaging features of prostatic stromal tumour of uncertain malignant potential

INTRODUCTION

Prostatic stromal tumours of uncertain malignant potential (STUMPs) are rare prostate tumours. The purpose of this study was to investigate the magnetic resonance imaging features of STUMPs.

METHODS

A total of 12 patients with STUMP confirmed with pathology who underwent MRI from 2012 to 2020 were retrospectively reviewed. Pathological characteristics including histopathology and immunohistochemistry were also recorded.

RESULTS

Among 12 STUMPs, the tumours were detected in the peripheral zone (41.7%[n = 5]) and transitional zone (58.3% [n = 7]) of the prostate. 8 cases (66.7%) were round shape. All lesions were well-defined and compressed the adjacent structures but without signs of an invasion. Homogeneous T1WI and heterogeneous T2WI signals were observed in the STUMPs. The tumours were mainly composed of solid components, while intratumoral cystic change (58.3%[n = 7]) and haemorrhage (8.3%[n = 1]) were seen. 10 cases(83.3%) were seen as relatively high DWI signal, while 2 cases(16.7%) with no increase in DWI. The mean ADC value was 1.084 ± 0.193 (range: 0.864-1.489 × 10^-3  mm² /s). STUMPs had heterogeneous enhancement, with persistent or gradual enhancement. In immunohistochemical staining, Vim, CD34, PR and SMA were positive in the majority of STUMPs.

CONCLUSION

MRI features of STUMP are presented as regular, well-defined and isolated prostatic mass with intact pseudocapsule. The presence of heterogeneous T2WI signal, intratumoral cystic change, slightly low mean ADC value and persistent or gradual enhancement may help predict the STUMPs.

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.

Clinical and Pathological Features of Prostatic Stromal Tumor of Uncertain Malignant Potential: A Retrospective Study of 23 Chinese Cases

INTRODUCTION

Prostatic stromal tumor of uncertain malignant potential (STUMP) is a rare disease that may coexist with prostate stromal sarcoma (PSS). We aimed to analyze the histological and clinical features of STUMP.

METHODS

Twenty-three patients diagnosed with STUMP from 2008 to 2019 were included. Clinicopathological and follow-up information was collected. In the subgroup analysis, we divided the patients into a pure STUMP group (N = 18) and a mixed STUMP (STUMP coexisting with PSS) group (N = 5). Student's t test was used to compare the 2 groups.

RESULTS

Patients had a mean age of 55.5 ± 19.4 years and an average follow-up time of 42.3 months. The mean prostate volume was 109.2 ± 73.5 cm3, and the mean prostate-specific antigen was 8.03 ± 10.5 ng/mL. In the subgroup analysis, 16.7% (2/12) of pure STUMP patients had disease progression, while 100% (3/3) of mixed STUMP patients suffered from recurrence. Compared with the pure STUMP group, the mixed STUMP group was younger (37.2 vs. 60.6 years, p = 0.013) and had lower expression of estrogen receptor and progesterone receptor (p = 0.004 and p < 0.001, respectively).

CONCLUSION

STUMP is a rare disease with a relatively good prognosis. However, there is still a possibility of disease progression or coexistence with stromal sarcoma. Timely diagnosis and regular monitoring may be helpful in improving treatment outcomes.

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

Stromal tumour of uncertain malignant potential of the prostate is a rare tumour with a variable clinical behaviour ranging from incidentally detected indolent tumours that never progress, to aggressive diseases almost identical to sarcomas that may invade surrounding organs or develop metastases. Surgical excision is generally recommended for local diseases; however, owing to its diverse clinical outcomes, optimal management may vary from surgery alone to wide excision combined with chemotherapy and/or radiotherapy. Therefore, preoperative evaluation of the malignant potential of the disease is essential to decide the treatment strategy. Herein, we report a case of stromal tumour of uncertain malignant potential successfully treated with minimally invasive robot-assisted radical prostatectomy alone under the diagnosis of the disease with low malignant potential based on the findings of positron emission tomography with 18F-fluorodeoxyglucose.

Stumped by rapid symptomatic prostatic regrowth: A case report on a STUMP tumour of the prostate resected with HoLEP

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Stromal tumour of Undetermined malignant potential (STUMP) of the prostate is a rare tumour arising from the prostate specialized stroma.

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The patient presented with LUTS, MRI showed prostatic growth, and biopsy showed no malignancy.

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The symptoms were treated by TURP and 11 g were removed of the prostate.

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The tumour recurred within less than a year to three times its original size.

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It is the first time in literature, HoLEP was used to remove the origin of the tumour successfully.

Introduction

Stromal Tumour of Undetermined malignant potential (STUMP) is a rare category of the prostate benign tumours, which has a variable clinical presentation, behavior and different approaches to manage it.

Case presentation

A 57 year-old male presented with voiding symptoms of the urinary tract and an increased PSA (14.7 ng/ml). Ultrasound and multiparametric MRI showed an enlarged prostate of 41 ml. Transurethral resection of the prostate (TURP) was performed with 11 g benign tissue removed. The patient presented one year later with the same symptoms; further ultrasound and parametric MRI demonstrated huge recurrence in the transition zone with a new prostate size of 131 ml.

Discussion

Despite no malignancy being identified in the initial TURP histology, the transition zone prostatic tumour behaved aggressively and recurred in just one year. For the first time in literature, the tumour recurred rapidly to three times the initial size and was removed using Holmium Laser enucleation of the prostate (HoLEP), after which no recurrence was seen in 11 months period.

Conclusion

HoLEP can be used to successfully enucleate STUMP tumours but the clinical behavior of the STUMP in prostate is still not understood well because of its rareness.

Lacrimal Sac Smooth Muscle Tumor of Uncertain Malignant Potential

A 13-year-old male presented with recurrent left nasolacrimal duct obstruction following endoscopic dacryocystorhinostomy 4 years prior at an outside institution. The past medical history was significant for stage IV neuroblastoma, diagnosed at age 2, requiring surgical resection, induction chemotherapy, autologous bone marrow transplantation and radiation, currently in remission. Preoperative CT scan demonstrated a 2 cm ovoid mass centered in the left lacrimal fossa, consistent with dacryocystocele; however, a solid tumor could not be ruled out. Subsequent surgical exploration of the lacrimal sac revealed a friable, solid mass filling the lacrimal sac, and extending into the duct. The mass was grossly resected with preservation of the lacrimal drainage system and placement of indwelling silicone stents. Histopathology confirmed the diagnosis of smooth muscle tumor of uncertain malignant potential. The patient remained free of epiphora and showed no clinical or radiographic evidence of recurrence at 6 months of follow up.

Beyond Prostate Adenocarcinoma: Expanding the Differential Diagnosis in Prostate Pathologic Conditions

Recent advances in magnetic resonance (MR) imaging of the prostate gland have dramatically improved the ability to detect and stage adenocarcinoma of the prostate, one of the most frequently diagnosed cancers in men and one of the most frequently diagnosed pathologic conditions of the prostate gland. A wide variety of nonadenocarcinoma diseases can also be seen with MR imaging, ranging from benign to malignant diseases, as well as infectious and inflammatory manifestations. Many of these diseases have distinctive imaging features that allow differentiation from prostate acinar adenocarcinoma. Early recognition of these entities produces a more accurate differential diagnosis and may enable more expeditious clinical workup. Benign neoplasms of the prostate include plexiform neurofibroma and cystadenoma, both of which demonstrate distinctive imaging features. Stromal neoplasms of uncertain malignant potential are rare tumors of uncertain malignant potential that are often difficult to distinguish at imaging from more-malignant prostate sarcomas. Other malignant neoplasms of the prostate include urothelial carcinoma, primary prostatic carcinoid, carcinosarcoma, endometrioid or ductal adenocarcinoma, and mucinous adenocarcinoma. Prostatic infections can lead to abscesses of pyogenic, tuberculous, or fungal origins. Finally, miscellaneous idiopathic disorders of the prostate include amyloidosis, exophytic benign prostatic hyperplasia, and various congenital cysts. Considerable overlap can exist in the clinical history and imaging findings associated with these prostate pathologic conditions, and biopsy is often required for ultimate confirmation of the diagnosis. However, many diagnoses, including cystadenoma, mucinous adenocarcinoma, sarcoma, and abscesses, have distinct imaging features, which can enable the informed radiologist to identify the diagnosis and recommend appropriate clinical workup and management. (©)RSNA, 2016.

Prostatic Stromal Tumor of Uncertain Malignant Potential Which Was Difficult to Diagnose

Here, we report a case of stromal tumor of uncertain malignant potential (STUMP) that was difficult to diagnose. A 53-year-old male was found to have a hard nodule on digital rectal examination; magnetic resonance imaging revealed a large nodule on the left side of the prostate, indicating prostate cancer. However, pathological diagnosis of the biopsy specimen was benign prostatic hyperplasia. Although a papillary tumor in the prostatic urethra was also seen on urethrocystoscopy, the tumor specimen obtained from transurethral resection was not malignant. The tumor in the prostatic urethra recurred only 3 months after transurethral resection, and pathological findings revealed benign hyperplasia not only in the stromal tissue but also in the epithelium; therefore, the prostate tumor was suspected to be STUMP. It took many prostate pathologists a long time to reach the final diagnosis of STUMP. STUMP is a rare benign tumor, difficult to diagnose, and sometimes transforms into stromal sarcoma. Thus, we should consider radical resection in such cases.

Is it really an abscess? An unusual case of metastatic stromal cell sarcoma of the prostate

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Prostatic stromal sarcomas account for about 0.1% of all prostatic malignancies.

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The preferred treatment is surgery by radical prostatectomy or cystoprostatectomy.

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Local recurrence occurs in to bladder, seminal vesicles and rectum.

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Distal metastasis, has so far only been reported in lung and bone.

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Subcutaneous metastasis of a prostatic stromal cell sarcoma has not been reported before.

Introduction

Prostatic stromal sarcomas account for about 0.1% of all prostatic malignancies. Local recurrence into bladder, seminal vesicles and rectum has been documented. Distal metastasis, has so far only been reported in lung and bone.

Presentation of case

We report the case of a 42 year old man with a subcutaneous metastatic deposit of a prostatic stromal cell sarcoma 5 years after radical prostatectomy. Additional staging with CT- and PET-scan showed lymph node involvement in the neck and left axilla. A core biopsy of the skin lesion was undertaken, of which the histology revealed a low grade spindle cell tumour that was morphologically identical to a previously diagnosed prostatic stromal sarcoma.

Discussion

In literature distant metastases to the lung and bone have been documented before. This is the first documented case of a subcutaneous metastasis of prostatic stromal cell sarcoma.

Conclusion

The preferred treatment for prostatic stromal cell sarcoma is surgery by radical prostatectomy or cystoprostatectomy. There is currently not enough literature on the topic to elucidate the role of chemo- or radiotherapy in loco-regional or distant spread.