Solitary fibrous tumor in the abdomen and pelvis: A case series with radiological findings and treatment recommendations

Robotic-assisted laparoscopic resection of a pelvic solitary fibrous tumour causing distal ureteric compression

This case report describes a male in his late 40s with a 4 cm pelvic mass compressing the left distal ureter, resulting in left hydroureteronephrosis. Biopsy of the mass was suggestive of a solitary fibrous tumour. The patient underwent a robotic-assisted laparoscopic excision of the left pelvic mass. Intraoperatively, the mass was found to be densely adhered to the ureter, necessitating a left distal ureterectomy and ureteric reimplantation. Subsequent histopathological analysis revealed the mass was a solitary fibrous tumour with no evidence of malignancy.

Solitary fibrous tumor within the mesorectum: literature review based on a case report of resection by transanal minimally invasive surgery (TAMIS)

PURPOSE

Solitary fibrous tumors (SFT) are a rare entity of in majority benign neoplasms. Nevertheless, up to 20% of cases show a malignant tendency with local infiltration or metastasis. Commonly arising in the thoracic cavity, only few cases of SFT of the mesorectal tissue have been reported in the literature. Complete surgical resection, classically by posterior approach, is the treatment of choice. The purpose of this review is to demonstrate the safety and suitability of transanal minimally invasive surgery (TAMIS) as a surgical approach for the resection of benign pararectal solid tumors.

METHODS

We report the case of a 52-year-old man who was diagnosed incidentally with SFT of the distal mesorectum. Resection by TAMIS was performed. Based on this case, we describe the steps and potential benefits of this procedure and provide a comprehensive review of the literature.

RESULTS

Histopathology confirms the completely resected SFT. After uneventful postoperative course and discharge on day four, follow-up was recommended by a multidisciplinary board by clinical examination and MRI, which showed a well-healed scar and no recurrence up to 3 years after resection.

CONCLUSION

SFT of the mesorectum is a very rare entity. To our knowledge, this is the first report on a TAMIS resection for SFT, demonstrated as a safe approach for complete resection of benign pararectal solid tumors.

Diagnosis and management of an extremely rare solitary fibrous tumor in the retropubic space of Retzius: A case report

INTRODUCTION AND IMPORTANCE

Solitary fibrous tumors (SFTs), rare mesenchymal tumors, occur in diverse locations. Retroperitoneal and pelvic SFTs are extremely uncommon, challenging to identify due to vague clinical and radiological features. We present a high-risk SFT case in the retropubic Retzius space.

CASE PRESENTATION

A 56-year-old woman with diabetes and bronchial carcinoid tumor had abdominal pain. Physical exam revealed hypogastric and pelvic masses. MRI showed a 16.5x12x8cm mass near the bladder. Initial laparotomy deemed it unresectable; biopsy indicated grade 2 FNCLCC mesenchymal tumor. In a second surgery, a 20 cm mass was successfully removed from the Retzius space. Histopathology confirmed SFT. Due to vaginal involvement, adjuvant radiotherapy was given. After 12 months, clinical and radiological follow-up showed remission. Unusual SFT location and successful treatment highlight the importance of comprehensive assessment and multidisciplinary approach in managing these rare tumors.

CLINICAL DISCUSSION

Solitary fibrous tumors (SFTs) are rare mesenchymal neoplasms, often found in extremities but seldom in the abdomen. Diagnosis is challenging due to vague symptoms and imaging. This case discusses an unusual SFT location in the pelvic space, requiring surgical removal. SFTs are typically benign but can be malignant, requiring wide resection and potential adjuvant therapy.

CONCLUSION

Diagnosing SFTs can be difficult because of their non-specific clinical and radiological characteristics, but imaging studies and biopsies can aid in the diagnosis. The preferred treatment for SFTs is surgical removal with clear margins, and regular follow-up is essential to watch for any signs of recurrence.

Multidisciplinary treatment of giant presacral solitary fibrous tumour: a case report and literature review

Solitary fibrous tumours (SFTs) usually occur at the pleura. Extrapleural sites, particularly giant extrapleural solitary fibromas, are more rarely observed in the clinic, and the clinical diagnosis and treatment of this disease is a focus of attention. Herein, the case of a 43-year-old male patient with giant presacral SFT successfully treated by open surgery, and with a final diagnosis confirmed by postoperative pathology and immunohistochemistry, is reported. The patient was followed-up regularly during 5 years after surgery, with no obvious surgical complications, and no tumour recurrence noted on pelvic magnetic resonance imaging. This case provides clinical information that may help in the diagnosis and treatment of complex SFT.

Mesentery solitary fibrous tumor with postoperative recurrence and sarcomatosis: A case report and review of literature

BACKGROUND

Solitary fibrous tumors are rare neoplasms of mesenchymal origin. They are often of low malignant potential and rarely metastasize. They frequently arise from the pleura and can occur at any soft tissue site in the body. However, these tumors rarely develop in the mesentery, peritoneal cavity or peritoneum.

CASE SUMMARY

We report on a scarce case of solitary fibrous tumor of the rectal mesentery showing sarcomatosis about 4 years after previous tumor resection. This 69-year-old male had no clinical symptoms but was transferred to our hospital because of a suspected tumor recurrence from follow-up abdominal computed tomography. Tumor markers (CEA, CA 19-9 and CA 125) were within the normal range. Open laparotomy showed sarcomatosis, and pathology confirmed its mesenchymal origin and diagnosis as the solitary fibrous tumor. Our case may be the second recurrent mesentery solitary fibrous tumor reported to date, and the only one with progression to sarcomatosis. There has been no evidence of recurrence in follow-up at the 28^th mo after extensive intra-operative peritoneal lavage and cytoreductive surgery.

CONCLUSION

Although there are few risk factors of cancer recurrence in this patient, careful long-term follow-up after cytoreductive surgery is necessary.

Primary intraperitoneal solitary fibrous tumor in mesentery: How does it present?

Intra-abdominal solitary fibrous tumor (SFT), also known as hemangiopericytoma, is rare, especially for those with a mesenteric location, and only a few cases have been reported. Distinguishing a hemangiopericytoma from other intra-abdominal benign or malignant tumors can be difficult, as they have similar presentations on both computed tomography and magnetic resonance imaging. In the present study, the records for a 31-year-old Vietnamese woman who underwent abdominal surgery for greater omental tumor resection and received histopathological results revealing SFT are retrospectively reviewed. The case is discussed and similar reported cases are reviewed. Due to the aggressive behavior and high rate of postoperative recurrence associated with SFT, a thorough understanding of the radiologic and histopathological features of the disease is necessary to achieve an appropriate diagnosis and treatment.

Transcatheter arterial embolization of malignant pelvic solitary fibrous tumor: case report and literature review

Pelvic malignant solitary fibrous tumor (SFT) is a relatively rare disease, and literature on radical resection with transcatheter arterial embolization of pelvic SFT is lacking. In this work, we report on a 55-year-old man with a presacral mass who was hospitalized at our department. Computed tomography and magnetic resonance imaging indicated pelvic space-occupying lesions that were 12 cm × 10 cm in size and pelvic lesions that were not clearly demarcated from the right posterior wall of the bladder and the right ureter. This result suggested severe secondary hydronephrosis of the right renal pelvis. The patient underwent transcatheter iliac arterial embolization. Radical tumor resection was performed, and the results of pathological examination confirmed the diagnosis of malignant pelvic SFT. There was no SFT recurrence in this patient at 1-year follow-up. Herein, we report on the treatment of a patient with malignant pelvic SFT, a rare condition, who underwent successful radical resection after transcatheter arterial embolization. Transcatheter arterial embolization can block the blood supply of the SFT as much as possible and improve the possibility of tumor resection. In the future, pelvic SFTs can be considered improving the resection rate by transcatheter arterial embolization before surgery.

Solitary fibrous tumors: Clinical and imaging features from head to toe

Solitary fibrous tumors (SFTs) are rare fibroblastic mesenchymal tumors that are usually benign with variable malignant potential. They can develop in any organ due to their spindle cell origin. The exact etiology of solitary fibrous tumors is unknown. The majority of SFTs are benign with 10-30% of them exhibiting aggressive and malignant features. The aggressiveness of this type of tumor is not associated with its histological features, which makes surgical resection the treatment of choice. We will review the clinical and radiological features and possible differential diagnoses of SFTs according to their anatomical sites following the World Health Organization 2020 classification.

Rare Mesenchymal Tumors of the Pelvis: Imaging and Pathologic Correlation

Most pelvic tumors originate from the organs. Less commonly, tumors can arise from the various anatomic pelvic compartments and are comprised of mesenchymal tissue: muscles, connective tissue, vessels, lymphatics, and fat. Among some of the rarer entities are benign tumors (eg, angiomyxoma, cellular angiofibroma, and desmoid fibromatosis), malignant tumors (eg, sarcoma), and tumors that can manifest as benign or malignant (eg, solitary fibrous tumor or nerve sheath tumor). Because these tumors are uncommon and often manifest with nonspecific clinical features, imaging (usually MRI) is an initial step in the evaluation. Radiologists interpreting these images are asked to help narrow the differential diagnosis and assess the likelihood of malignancy for treatment planning. Thus, the MRI report should include the imaging features that would indicate the underlying tissue histology for pathologic diagnosis as well as a description of the anatomic extent and pattern of growth. The authors describe multiple locally aggressive benign and malignant mesenchymal tumors and highlight characteristic clinical and imaging features that enable the radiologist to narrow the differential diagnosis. The anatomic spaces of the pelvis are reviewed with illustrations to aid the radiologist in describing these tumors, which often span multiple pelvic compartments. Tumor appearance at T2-weighted, diffusion-weighted, and postcontrast MRI is summarized and illustrated with correlation at CT or fluorodeoxyglucose PET/CT, when available. MRI features that correspond to specific types of tissue (eg, myxoid, fibrous, or vascular) are highlighted and correlated with images from pathologic evaluation. Online supplemental material is available for this article. ^©RSNA, 2021.

A rare case of rectal bleeding and Fusobacterium mortiferum sepsis due to solitary fibrous tumour originating from the mesentery

Solitary fibrous tumours (SFTs) are rare mesenchymal tumours that are mostly seen in the pleura. Lately, they have also been described in other locations. Recent discovery of the NAB2-STAT6 fusion gene which is specific for SFTs has led to an accurate diagnosis of SFTs. The occurrence of SFTs in the mesentery is very rarely reported in the literature. We report a case of a 63-year-old female who presented with abdominal pain, rectal bleeding and Fusobacterium bacteraemia, who was ultimately found to have a mesenteric SFT.

Doege-Potter syndrome: a systematic review of the literature and case presentation of a rare pelvic malignant solitary fibrous tumour

Solitary fibrous tumours (SFTs) are a rare mesenchymal neoplasm with an incidence of 2.8 per 100 000 of which only 1% occur in the female genital tract. Doege-Potter syndrome is a paraneoplastic phenomenon associated with approximately 5%-10% of SFTs and is characterised by non-islet cell hypoglycaemia due to tumour production of low molecular weight insulin-like growth factor-II. We present the fourth confirmed case of female pelvic SFT with Doege-Potter syndrome and a literature review.

Perianal Solitary Fibrous Tumor in a Rare Anatomical Presentation: A Case Report and Literature Review

BACKGROUND Solitary fibrous tumors (SFTs) account for <2% of all soft tissue tumors and are slow-growing neoplasms of mesenchymal origin, which have been reported in various locations. They are frequently observed at the pleura and a perianal location is extremely rare. They show no predisposition by sex, are mainly benign, and usually occur between the 5th and 7th decades of life. CASE REPORT We report the case of an 80-year-old man with no comorbidities except hypertension, who presented with an asymptomatic perineal mass. Magnetic resonance imaging showed a solid tumor measuring 3.5×2.5 cm identified in the perineal midline. It was very close to the anal sphincter, showing no extension to the rectum or anus. The tumor was completely excised with negative margins. The postoperative course was uneventful and he was discharged home, free of any symptoms. The pathological examination showed a benign completely excised SFT, and no further treatment was necessary. At the 6-month and 1-year follow-ups, there was no sign of recurrence. CONCLUSIONS A comprehensive review of all the reported cases of perianal SFTs shows that the majority of these tumors present with no symptoms and have a favorable prognosis. Diagnosis is possible only after a pathological examination. The criterion standard of treatment is complete excision with negative margins. Once excised, the tumors have low rates of recurrence and metastasis. Tumors very close to the anal sphincter and with malignant potential need to be operated on with extra care to obtain clear margins without disrupting the continence mechanism.

Robot-assisted laparoscopic resection of a pelvic solitary fibrous tumor

Solitary fibrous tumor (SFT) is a rare soft tissue neoplasm of mesenchymal origin. SFT is most commonly located in the thoracic cavity (in approximately 80% of cases), but can also develop rarely in the pelvis. A 47-year-old man presented to our hospital with a pelvic tumor that was discovered during a health checkup. We performed transperitoneal robotic resection of the pelvic tumor. Intraoperative blood loss and the console time were 100 mL and 2 hours 42 minutes, respectively, and no intraoperative or postoperative complications were recorded. Histologic analysis revealed a pelvic SFT with negative surgical margins. The patient was followed-up for 13 months with no evidence of tumor recurrence. To our knowledge, this is the first report of robot-assisted laparoscopic resection of a pelvic SFT.

Solitary Fibrous Tumor in the Perianal Region: Report of Two Cases With an Atypical Location

A solitary fibrous tumor (SFT) is a mesenchymal neoplasm of spindle cells, initially described in the pleura. The World Health Organization (WHO) classifies the solitary fibrous tumor as a neoplasm with intermediate biological potential. Diagnostic images are essential for the diagnostic and therapeutic approach in this entity. The standard of treatment for this type of lesion is surgical resection with oncological margins larger than 1 cm. The solitary fibrous tumors located in the perianal, perineal, and pelvic regions are infrequent and represent a challenge in the clinical approach, mainly because the manifestations are nonspecific. Given the low incidence of this type of neoplasm, we present two cases of SFT in the perianal region managed in a high-complexity hospital.

Solitary fibrous tumor with atypical features of the paravesical space: benign clinical course at the 10-years follow-up. Report of a case and review of the literature

Extra-pleural solitary fibrous tumor (SFT) is a relatively rare soft tissue neoplasm, with only rare cases reported in the pelvic cavity. Most SFTs are histologically benign, with only a few malignant cases reported in the literature so far. We report a rare case of SFT arising in the paravesical space of a 79-year-old man. Histologically the tumor corresponds to an “intermediate risk tumor” according to a risk stratification scheme for metastatic potential, which incorporates patient age, tumor size, mitotic activity and necrosis. Notably tumor showed a benign clinical course without evidence of local recurrence after a 10-years follow-up. Tumor was composed of both spindle and epithelioid cells variably set in a fibro-myxoid stroma, with focal pleomorphic, necrotic and highly mitotic (> 4 mitoses/10HPF) areas. Immunohistochemistry, showing a diffuse CD34 and STAT6 immunoreactivity, supported the diagnosis of SFT. The present case emphasizes that the clinical course of the pelvic SFTs with atypical morphological features is unpredictable on the basis of morphology alone, and thus the term “SFT with atypical features, including the risk stratification class” should be preferred to “malignant SFT”.

Novel technical modifications of hand-assisted laparoscopic dissection of a large obturator mass: A case report and literature review

Laparoscopic lateral pelvic tumor dissection (LLPTD) for transobturator tumors may be technically challenging due to the requirement for sufficient operative space. The present study discusses a technique modification with combination of the laparoscopic approach and hand-assisted (HA) open surgery for patients with large obturator masses. LLPTD was performed using the combined approach, defined as HA-LLPTD, with one case treated. According to this technique, a combined working space is constructed based on the outreached laparoscopic space and open extraperitoneal approach, followed by HA-LLPTD. Finally, a literature review was performed to retrospectively evaluate 17 cases of obturator tumors, in terms of tumor type and operative approach. The tumor in the present case was successfully and completely resected, without any obvious intra- and post-operative complications. Based on the literature review, the majority of the cases were benign (~75%) and originated from neurological tissue (~50%). The selection of the operative approach was either open or minimally invasive (50% each). HA-LLPTD allows experienced urological laparoscopic surgeons to safely and completely perform obturator surgery without obstruction of the obturator foramen or formation of intraperitoneal adhesions and associated complications. Therefore, HA-LLPTD may be more useful for transobturator tumor resection compared with the conventional intraperitoneal approach.

Solitary Fibrous Tumor of the Prostate

Even though most tumors located in the prostate derive from prostatic glands, there is a long list of malignant and nonmalignant causes for prostatic growths that clinicians should be aware of. Tumors of the prostate can be grouped in epithelial, neuroendocrine, stromal, mesenchymal, hematolymphoid, and miscellaneous. Solitary fibrous tumor of the prostate (SFT), is an extremely rare mesenchymal tumor (only about 20 cases reported in the literature). Histologic features resemble those of the more common variant pleural SFT. Of all, 10%-20% of SFTs, also known as malignant SFTs, behave aggressively. Herein, we describe a case of prostatic SFT in a 66-year-old patient that presented with obstructive urinary symptoms and normal prostate-specific antigen levels.

Solitary fibrous tumor of the scrotum: a case report and review of the literature

BACKGROUND

Solitary fibrous tumor (SFT) is a rare soft tissue tumor originally reported in the pleura. Although it has been reported in various extra-pleural sites, the occurrence of SFT in the scrotum is extremely rare. Herein, we present a 48-year-old man who had scrotal SFT. There are very few reported cases of genitourinary SFTs, this is only the fifth report of SFT of the scrotum in the English medical literature.

CASE PRESENTATION

In this study, we report on a 48-year-old man who presented with a 5 × 8 cm scrotal mass between his testes. Physical examination revealed a 4.7 × 8.5 cm lobulated tumor mass located between his testicles. Surgical excision of the tumor with scrotal approach was done and pathology reported a SFT. The patient was alive without tumor recurrence or distant metastasis during ongoing follow-up for 9 months post-operatively..

CONCLUSION

Scrotal SFTs are very rare and only five cases have been reported in English literature to date. Treatment often involves surgical resection, and a definite diagnosis is made with the help of immunohistochemistry. The current general consensus for the management of SFTs is long-term follow-up after surgical excision of the tumor.

Solitary fibrous tumor arising from pelvic retroperitoneum: A report of two cases and a review of the literature

Solitary fibrous tumors (SFT) rarely arise in the pelvis. Here, we report two cases of SFT arising from the pelvic retroperitoneum. The first case involves a 64-year-old woman diagnosed with a 5-cm pelvic mass. Magnetic resonance imaging revealed a solid and cystic mass with marked enhancement, but limited water restriction. During surgery, intraligamental tumor arising near the round ligament was resected. Pathologically, the tumor comprised dilated vessels and spindle-shaped cells positive for STAT6 and CD34. The second case involves a 53-year-old woman diagnosed with a 4.5-cm pelvic mass through computed tomography. Magnetic resonance imaging demonstrated a solid mass with multiple cysts with strong enhancement and slight water restriction. During surgery, the tumor was found in the retroperitoneum. Pathologically, spindle-shaped tumor cells positive for STAT6 and CD34 had proliferated around the prominent hyalinized vessels. Although rare in the pelvis, SFT should be suspected when a mass with strong enhancement is found.

Solitary fibrous tumor/hemangiopericytoma of the penis

Solitary fibrous tumor/hemangiopericytoma (SFT-HMP) is a rare spindle-cell mesenchymal tumor, thought to be of myofibroblastic origin. Penile SFT-HMP was mentioned in the literature in two separate case reports which were published in 2015 and 2017. We present the first case of SFT-HMP which is localized on corpus cavernosum of the penis. A 55-year-old man presented to our clinic with a small and gradually growing lesion on his penis for the past year, which recently caused difficulties during sexual intercourse. On physical examination; a well-shaped, nodular non-fluctuant, solid, painless mass, measuring 4×4 cm was palpated. Magnetic resonance imaging showed 5×5 cm mass located on the right corpus cavernosa. Under spinal anesthesia, surgical excision was performed. Pathologically, the tumor had an irregular architecture patterns and was characterized by hypercellular areas separated by thin-walled, branching vessels, lined with a single layer of flattened endothelial cells. SFT-HMP rarely occurs in genital tract and penile presentation is among the rarest. It should be classified and considered under penile masses, especially if the mass is well circumscribed, painless and slowly growing in nature. After differential diagnosis, surgical excision is mandatory.