Inflammatory myofibroblastic tumors of the genitourinary tract--single entity or continuum?

Postoperative Spindle Cell Nodule Mimicking Metastatic Lesion With Persistently Increasing 68 Ga-FAPI-04 Uptake After Receiving Personalized Antigen Peptide Tumor Vaccine

ABSTRACT

A 59-year-old woman underwent radical surgery and chemotherapy for gastric adenocarcinoma. After the personalized antigen peptide tumor vaccine, a new nodular lesion, in the upper abdomen, was discovered during 68 Ga-FAPI-04 PET/MRI follow-up. To determine possible pseudoprogression, 68 Ga-FAPI-04 PET/MRI was repeated 39 days later, referring to immune PET response criteria in solid tumors. The lesion showed increased 68 Ga-FAPI-04 uptake, whereas uptake in vaccine injection sites decreased, and was ultimately diagnosed as a postoperative spindle cell nodule.

Inflammatory myofibroblastic tumor of the bladder turn malignant: A case report

INTRODUCTION AND IMPORTANCE

Inflammatory myofibroblastic tumor (IMT) of the bladder is a rare sight, which can be distinguished by the proliferation of spindle cells and the presence of a persistent chronic inflammatory infiltrate. IMT is usually benign, but in a few cases it has a tendency for malignant transformation and metastases.

CASE PRESENTATIONS

A 30-year-old male with a history of recurrent hematuria. His initial symptoms was unfrequent painless hematuria. Abdomen multislice computerized tomography (MSCT) with contrast shows an enhancing solid mass with necrotized center measuring +/- 12.9 × 16.5 × 18.9 cm and extending from cavum pelvis to cavum abdomen. Cystectomy and bilateral ureterocutaneostomy were performed. The histology report found an IMT with mitotic cells, a necrotic region, and a positive ki67, which suggest the tumor's malignant transformation. Unfortunately, the patient's overall condition continued to deteriorate, and he passed away seven days after hospital discharge.

CLINICAL DISCUSSIONS

IMT is comprised of spindel cells and inflammatory cells. IMT might become aggressive locally, recurring, or progress to malignancy. Fifty percent of IMTs are caused by rearrangements of the anaplastic lymphoma kinase (ALK) gene on chromosome 2p23, resulting in ALK-1 overexpression. A change from uniform spindled cells to atypical polygonal cells or plump cells with oval vesicular nuclei, prominent nucleoli, and mitoses is indicative of malignant transformation.

CONCLUSION

This case emphasizes the importance of continuous monitoring and raising awareness about the possibility of malignant transformation of IMT. Understanding the characteristics of the findings could result in better decision-making and outcomes.

Single-cell profiling reveals various types of interstitial cells in the bladder

Clarifying the locations, molecular markers, functions and roles of bladder interstitial cells is crucial for comprehending the pathophysiology of the bladder. This research utilized human, rat and mouse bladder single-cell sequencing, bioinformatics analysis and experimental validation. The main cell types found in human, rat and mouse bladder tissues include epithelial cells, smooth muscle cells, endothelial cells, fibroblasts, myofibroblasts, neurons and various immune cells. Our study identified two significant types of interstitial cells (PTN+ IGFBP6+ PI16 (CD364)+ CD34+ ) and myofibroblasts (STC1+ PLAT+ TNC+ ). These two types of interstitial cells are mainly located in the subepithelial lamina propria, between muscles and between muscle bundles. In the CYP (cyclophosphamide)-induced bladder injury mouse model, the interaction types and signals (MK, MIF, GDF and CXCL) of fibroblasts and myofibroblasts significantly increased compared with the normal group. However, in the aging mouse model, the signals CD34, LAMININ, GALECTIN, MK, SELPLG, ncWNT, HSPG, ICAM and ITGAL-ITGB2 of fibroblasts and myofibroblasts disappeared, but the signals PTN and SEMA3 significantly increased. Our findings identified two crucial types of interstitial cells in bladder tissue, fibroblasts and myofibroblasts, which play a significant role in normal bladder physiology, CYP-induced bladder injury and aging bladder development.

USP6-associated neoplasm as a tentative subset of postoperative spindle cell nodule

AIM

Postoperative spindle cell nodule (PSCN) is a pseudosarcomatous proliferative lesion of unclear molecular genetic origins.

METHODS AND RESULTS

We examined seven patients with PSCN, using routine haematoxylin-eosin (H&E) slide preparations and a series of immunostains. The latter targeted keratin, vimentin, α-smooth muscle actin (SMA), anaplastic lymphoma kinase (ALK [D5F3]), and other proteins. Ubiquitin-specific peptidase 6 (USP6) and anaplastic lymphoma kinase (ALK) gene rearrangements were also analysed by fluorescence in situ hybridization (FISH). There were histories of prior surgical intervention (n = 6) or trauma (n = 1) in all seven patients. All lesions were highly cellular and mitotically active spindle cell proliferations, with no cytologic atypia, nuclear pleomorphism, or aberrant mitoses. Immunohistochemical (IHC) staining disclosed focal, weak keratin positivity in two lesions, whereas vimentin (diffuse, strongly positive) and SMA (tram-track pattern) were present in each instance, and ALK (D5F3) was entirely negative. FISH analysis confirmed USP6 gene rearrangements in all seven cases, showing no ALK gene rearrangements. RNA sequencing results showed an MYH9::USP6 gene fusion in only one lesion (No. 6).

CONCLUSION

A subset of PSCN is marked by USP6 gene rearrangements, a genetic feature of nodular fasciitis (NF). Given its similarity to NF, a designation as USP6-associated neoplasm (UAN) seems reasonable, signifying a transient clonal neoplastic lesion.

Case report: Emergency management of spontaneous rupture of the inflammatory myofibroblastic tumor of the urinary bladder

Acute abdomen caused by spontaneous rupture of the inflammatory myofibroblastic tumor of the urinary bladder (IMTUB) is a rare clinical emergency of the urinary system.It is difficult to distinguish it from spontaneous rupture of bladder caused by other causes before surgery. An emergency case of spontaneous rupture of IMTUB was reported. A 57-year-old middle-aged woman was admitted to the hospital because of “acute lower abdominal pain for 5 hours”. No history of smoking and gross hematuria. The physical examination revealed visible abdominal tenderness as well as signs of shock. A pelvic CT scan shows a space-occupying lesion above the bladder with massive accumulation of blood. When the nature of the tumor could not be determined, emergency laparotomy and partial cystectomy were performed, and postoperative pathology confirmed cystitis myofibroblastic tumor. No local recurrence or distant metastasis of the tumor was observed during the regular follow-up period of 6 months. IMTUB should focus on prevention and treatment, with a combination of preoperative examination and postoperative pathology, and finally implement highly individualized treatment.

Spindle cell tumours of the ureter: Operation or observation?

We describe a rare case of inflammatory spindle cell tumour of the ureter in a patient who presented with renal colic and macroscopic haematuria. Pyeloscopy revealed a partially obstructing mass at the proximal right ureter which confirmed a myofibroblastic tumour on biopsy. Radical nephrectomy was performed which confirmed a spindle cell tumour of the ureter confined to the resection margins. Follow-up imaging in 12 months did not illustrate recurrence or metastasis. The decision to perform a nephrectomy was due to the limited experience with this tumour. Reports illustrate that this tumour is unlikely to metastasize, and thus be managed conservatively.

•

Benign spindle cell tumours/inflammatory myofibroblastic tumours (IMTs) of the ureter are exceedingly rare.

•

Histologically they may mimic low grade genitourinary sarcomas and therefore good histological assessment needs to be sort.

•

Kidney sparing surgery should be offered to suitable patients.

•

Close clinical and radiological observation can be offered to suitable patients.

•

Surgery is likely to be curative without the need for ongoing surveillance.

A rare case of inflammatory myofibroblastic tumor of the vulva in a newborn

Inflammatory myofibroblastic tumor (IMT) is an uncommon neoplasm that rarely arises in the genitourinary system. IMTs in the vulva in infants are extremely rare in the literature. The tumor consists of myofibroblastic spindle cells accompanied by inflammatory cell infiltration. In this article, we aimed to describe the case of IMT in the vulva. A newborn girl presented with a mass in the vulva detected in the prenatal period. The patient was treated with surgery and chemotherapy. Follow-up 8 months after surgery showed no signs of recurrence. In conclusion, IMT has a variable clinical presentation, surgery is the optimal approach, but in cases without complete resection, chemotherapy is essential.

Sarcomatoid Urothelial Carcinoma With Myxoid Stroma: A Case Report and Diagnostic Approach

Bladder cancer is the seventh most common cancer in the world. Urothelial carcinoma is the most common type of bladder cancer. Other subtypes like squamous cell carcinoma and adenocarcinoma are less common. Urothelial carcinoma has a propensity for divergent differentiation. Sarcomatoid carcinoma is one of the variants of urothelial carcinoma. It is an aggressive tumor that presents at an advanced stage and has a poorer prognosis than conventional urothelial carcinoma. Therefore, identifying this variant histology is important clinically. The sarcomatoid component in sarcomatoid carcinoma can be spindle cell (not otherwise specified), myxoid, pseudoangiosarcomatous, and undifferentiated sarcoma like. Myxoid stroma in sarcomatoid urothelial carcinoma has been described but reported very rarely. We present a case of sarcomatoid urothelial carcinoma with myxoid stroma along with a review of the diagnostic approach to myxoid spindle cell lesions of the urinary bladder.

A Conservative Approach to Inflammatory Myofibroblastic Tumor of the Bladder: A Case Report and Review of Literature

Inflammatory myofibroblastic tumors (IMTs) are particularly rare tumors that have been described in various anatomic locations, of which the urinary bladder is the most common. These benign tumors are amendable to conservative therapy but are notoriously difficult to diagnose given their mimicry of malignant sarcomas and sarcomatoid carcinomas, making an accurate diagnosis paramount to spare a patient radical and unnecessary treatment. We hereby present the case of a 37-year-old female patient who was diagnosed with an IMT of the urinary bladder during workup for painless gross hematuria. Patient was successfully managed with a laparoscopic partial cystectomy and is free of recurrence 5 years after surgery. IMTs are rare benign tumors that share the same clinical presentation as malignant bladder tumors. Deep biopsy and experienced pathologist are crucial in establishing diagnosis and avoiding patient radical treatment. This case is a classical demonstration of a remarkably rare tumor that was adequately managed with conservative therapy, achieving excellent clinical outcomes.

TERT promoter mutation analysis as a surrogate to morphology and immunohistochemistry in problematic spindle cell lesions of the urinary bladder

AIMS

Pseudosarcomatous myofibroblastic proliferations (PSMPs) of the urinary bladder are diagnostically challenging. Diagnostic difficulties are mainly due to frequent cytokeratin expression, variable ALK expression and worrisome morphological features suggestive of malignancy. Conversely, sarcomatoid urothelial carcinoma (UC) may show bland inflammatory myofibroblastic tumour (IMT)-like morphology. TERT promoter mutations are characteristic events in urothelial cancers, but have not been studied in PSMPs.

METHODS AND RESULTS

We compared histomorphological and immunohistochemical features and TERT promoter status in 16 PSMPs and 18 sarcomatoid UC. In a subset of PSMPs, RNA sequencing was performed. At least focal IMT-like morphology was seen in nine of 17 sarcomatoid UC. Atypical mitoses, differentiated urothelial component and heterologous elements were the most reliable distinguishing histomorphological features of sarcomatoid UC, if present. A panel of immunohistochemistry (IHC) including ALK (clone D5F3), p53 pattern, p63 and GATA3 reliably distinguished PSMP from sarcomatoid UC. GATA3 (P = 0.001) and p53 patterns (mutant versus wild-type; P < 0.001) were differentially expressed between PSMPs and sarcomatoid UC. Diffuse pancytokeratin staining was significantly associated with PSMPs (10 of 13) compared to four of 14 sarcomatoid UCs (P = 0.012). TERT promoter mutations were found in 17 of 18 sarcomatoid UC versus none of 16 PSMPs (P < 0.001). RNA sequencing revealed ALK genetic rearrangements in one of two ALK-positive and one of 10 ALK-negative PSMPs, which revealed a novel FN1/RET gene fusion.

CONCLUSION

Careful histomorphological analysis and differential IHC reliably distinguish the majority of PSMPs and sarcomatoid UC. In equivocal cases, TERT promoter mutation analysis and/or detection of ALK expression/rearrangements are valuable additional diagnostic adjuncts, strongly supporting sarcomatoid UC and PSMP, respectively.

Inflammatory Myofibroblastic Tumor of the Urinary Bladder and Ureter in Children: Experience of a Tertiary Referral Center

PURPOSE

To present the clinicopathological characteristics and outcome of children with bladder and ureteral inflammatory myofibroblastic tumors (IMTs) in our center.

METHODS

We reviewed the medical records of patients with bladder and ureteral IMTs from 2010 to 2018. We recorded patients' demographic data, presentation, hemoglobin level, presence of hydronephrosis, tumor size, treatment, and outcomes.

RESULTS

Eight patients with bladder IMTs and 3 with ureteral IMTs were treated at our center during this period. The mean age was 7.1 years. Four patients presented with anemia at diagnosis with the mean hemoglobin level 84.5 g/L. Among patients with bladder IMTs, 5 were male and 3 were female. The most common symptom was lower urinary symptoms in 6 patients, followed by hematuria in 4 patients. 2 patients had complications of hydronephrosis and hydroureter. Among patients with ureteral IMTs, 2 were male and one was female. The most common symptom was abdominal pain, and 3 patients presented with upper urinary tract dilation. All patients underwent surgery. A total of 81.8% were positive for anaplastic lymphoma kinase. Cytokeratin (CK) expression was present in all patients with bladder IMTs, while it was negative in 2 patients with ureteral IMTs. During mean follow-up of 43.4 months, all patients survived event-free.

CONCLUSION

The presence of hydronephrosis and hydroureter is rare in patients with bladder IMTs. Anemia caused by hematuria should be raised the index of suspicion for IMTs. Children with bladder and ureteral IMTs had excellent prognosis. The expression pattern of CK varied between bladder and ureteral IMTs.

Metastatic inflammatory myofibroblastic tumor of the bladder

A 61-year-old male presented with gross hematuria and transurethral resection of bladder tumor revealed inflammatory myofibroblastic tumor (IMT). Due to extent of disease leading to ureteral obstruction and hydronephrosis, radical cystectomy (RC) with ileal conduit urinary diversion was performed. Five months after RC, the patient presented with decreased urine output. Exploratory laparotomy revealed mass in right colon and right hemicolectomy revealed metastatic IMT to the bowel and pericolonic fat. To our knowledge, this is the first report of primary IMT of the bladder metastasizing to other organs.

A rare inflammatory myofibroblastic bladder tumor masquerading urachal carcinoma

Inflammatory pseudotumor is a rare benign condition of unknown cause. A 19-year-old female presented with gross hematuria and storage symptoms to the emergency. Contrast-enhanced computed tomography scan revealed a mass of 5 cm × 6 cm involving the dome and anterior wall of the bladder. Urachal carcinoma was kept as a possibility and transurethral biopsy of the aforementioned lesion was performed. The histopathology revealed inflammatory myofibroblastic tumor (IMT) of the bladder. A laparoscopic partial cystectomy was undertaken with adequate resection margins and the histopathology of the lesion confirmed IMT. When evaluating a mass in the genitourinary tract in a young individual, IMT should be considered as a possibility.

Pseudosarcomatous myofibroblastic proliferations of the genitourinary tract are genetically different from nodular fasciitis and lack USP6, ROS1 and ETV6 gene rearrangements

AIMS

Pseudosarcomatous myofibroblastic proliferations of the genitourinary tract have a debatable relationship with inflammatory myofibroblastic tumour (generally lacking ALK rearrangement); however, they share several overlapping features with nodular fasciitis of soft tissue. As rearrangement of the USP6 gene has been recently recognised as a recurrent alteration in soft tissue nodular fasciitis, and several other alternative gene fusions have been recently recognised in inflammatory myofibroblastic tumour, the aim of this study was to investigate whether USP6, ROS1 or ETV6 rearrangements were present in these lesions (12 cases).

METHODS AND RESULTS

Fluorescence in-situ hybridisation analysis was performed by the use of bacterial artificial chromosome-derived break-apart probes against USP6, ROS1, and ETV6. Two cases with adequate genetic material from recent paraffin tissue blocks were also tested by use of a solid tumour gene fusion detection assay via next-generation sequencing, targeting >50 known genes involved in recurrent fusions. None of the genitourinary pseudosarcomatous myofibroblastic proliferations was found to harbour USP6 (0/12), ROS1 (0/8) or ETV6 (0/7) rearrangements, and no gene fusions were detected in two cases studied by sequencing.

CONCLUSIONS

Despite overlap in histological and immunohistochemical features between pseudosarcomatous myofibroblastic proliferation and nodular fasciitis, these tumours lack the recently recognised USP6 rearrangements that occur in nodular fasciitis, as well as alternative fusions found in ALK-negative inflammatory myofibroblastic tumours. At present, this diagnosis remains based primarily on clinical, histological and immunohistochemical features.

Neoadjuvant crizotinib in ALK-rearranged inflammatory myofibroblastic tumor of the urinary bladder: A case report

INTRODUCTION

Inflammatory myofibroblastic tumor (IMT) is a rare mesenchymal tumor that involves various organs, but has a predilection for the urinary bladder in the genitourinary tract. Given that approximately half of all IMT cases have anaplastic lymphoma kinase (ALK) rearrangements, the ALK inhibitor crizotinib is suggested as a promising treatment for unresectable cases. No reports on neoadjuvant crizotinib therapy for locally advanced IMT of the bladder are available.

PRESENTATION OF CASE

We report a case of a 17-year-old Japanese boy referred to our institution for painful urination and increased urinary frequency. He was diagnosed with ALK-positive IMT via transurethral resection of the bladder tumor. Computed tomography (CT) revealed a 5-cm mass and extramural invasion at the bladder dome. The diagnosis was locally advanced IMT of the bladder. We decided that partial cystectomy can be performed if neoadjuvant crizotinib therapy reduced the tumor size. After 2 months of administration, CT showed that the longest tumor diameter was reduced by 48%. Thus, we performed partial cystectomy, and the surgical margin was negative. No recurrence developed for over 1 year.

DISCUSSION

IMT has intermediate malignant potential because its clinical course is relatively indolent with low risk of distant metastasis. As this patient is young and IMT of the bladder has good prognosis after surgical resection, bladder-preserving surgery is the most preferred approach.

CONCLUSION

Neoadjuvant crizotinib therapy may be effective for large, locally advanced, and difficult to resect tumors.

Computed Tomography and Magnetic Resonance Imaging Findings of Inflammatory Pseudotumors in the Abdomen and Pelvis: Current Concepts and Pictorial Review

The group of inflammatory pseudotumors (IPTs) encompasses a variety of rare neoplastic and nonneoplastic entities described to occur in almost every location in the body and whose clinical features and aggressive imaging findings (varying from infiltrative to mass-forming lesions), frequently mimic those of malignant tumors. The radiologic features of IPTs are variable and nonspecific, the imaging findings depending on the body location and involved organ. Abdominopelvic IPTs are rare and the purposes of this review, therefore, are to familiarize the radiologist with the wide spectrum of computed tomography and magnetic resonance imaging findings of IPTs in various locations throughout the abdomen and pelvis, discussing the imaging features that allow consideration of IPTs in the differential diagnosis of soft-tissue masses within the pertinent clinical setting. Radiologists should be aware of this group of entities, as a preoperative histopathologic diagnosis upon radiological suspicion may help to differentiate IPTs from malignancy and to allow the most appropriate clinical work-up for these patients.

Benign testicular neoplasm in a human immunodeficiency virus-positive patient masquerading as testicular cancer

Inflammatory myofibroblastic tumor (IMT) is a rare, benign neoplasm comprising spindle myoepithelial cells in the background of inflammatory cells. It can involve multiple anatomic sites in the body but rarely involves the testis. We report a case of 52-year-old male patient with a history of human immunodeficiency virus who presented with a painless, testicular mass for 2 months. Despite being treated with prolonged antibiotics and nonsteroidal anti-inflammatory drugs, scrotal ultrasound demonstrated an increase in the size of the lesion. With a presumed diagnosis of testicular germ cell tumor, a right radical inguinal orchiectomy was performed. Microscopic and immunohistochemical features were consistent with testicular IMT, a benign neoplastic process.

Inflammatory myofibroblastic tumour of the bladder in children: a review

INTRODUCTION

Inflammatory myofibroblastic tumours of the bladder (IMTB) are rare, and feature a benign and reactive proliferation of myofibroblasts. 25% of the reported IMTB cases in the literature occur in children. The present study presents a review of IMTB in children.

DISCUSSION

The data from 42 reported cases of paediatric IMTB in the world literature are summarised, including two recent cases from the present centre. Paediatric IMTB equally affects males and females. It mainly presents with haematuria, dysuria or abdominal pain. Lesions can vary in size, but mean size is 5.5 cm. Mean age is 7.5 years. The aetiology of IMTB is poorly understood, but includes infective or traumatic aetiologies, or a possible clonal lesion. IMTB may specifically show clonal gene rearrangements involving the anaplastic lymphoma kinase (ALK-1) gene. To differentiate IMTB from rhabdomyosarcoma, tissue diagnosis and careful histological analysis are essential. Tumour biopsy can be achieved by a transurethral approach or a transcutaneous approach with ultrasound guidance. Between 35 and 89% of cases of IMTB express ALK-1 by immunohistochemistry. ALK-1 expression is much less common in other bladder soft tissue tumours. ALK-1 is thus useful in the diagnosis of IMTB. The treatment of choice for IMTB is complete surgical resection of the lesion. In children, no proven recurrent or metastatic IMTB episodes are reported after excision. However IMTB recurrences are reported in adults, likely due to incomplete excision. Follow-up after excision is therefore recommended.

CONCLUSIONS

Paediatric IMTB is uncommon. Tissue biopsy is essential for diagnosis. Careful histological assessment is required to differentiate IMTB from malignant paediatric bladder tumours such as rhabdomyosarcoma. ALK-1 expression is useful in confirming the diagnosis of IMTB. Treatment of choice is complete surgical resection of the lesion. Recurrence is reported in adult IMTB. Follow-up is therefore recommended.

Inflammatory myofibroblastic tumor of the bladder

We illustrate a case of an inflammatory myofibroblastic tumor (IMT) involving the bladder in a woman with dysuria and review the literature and differential diagnosis. Inflammatory myofibroblastic tumor, also referred to as pseudosarcomatous myofibroblastic proliferation, is a rare lesion that can arise in the genitourinary system and is characterized by a fascicular arrangement of myofibroblasts with admixed inflammatory cells and slitlike vessels. Urinary bladder IMT can be a diagnostic pitfall because its histologic features (brisk mitoses, invasion into muscularis propria, and prominent nucleoli) can mimic malignancy. The differential diagnosis of urinary bladder IMT includes sarcomatoid carcinoma and leiomyosarcoma. Diagnostic features such as bland nuclear chromatin, ganglion-like cells, pale eosinophilic cytoplasm with long processes, overexpression of anaplastic lymphoma kinase (immunohistochemistry or gene rearrangement studies), and the absence of atypical mitoses help distinguish IMT from its malignant mimics. Current controversies regarding postoperative spindle cell nodule and IMT are discussed.

Pelvic inflammatory myofibroblastic tumour mimicking scrotal mass: an extremely rare case

Inflammatory myofibroblastic tumour (IMT) is a rare benign mesenchymal tumour. However, IMT may arise from a wide variety of tissues and is very rare in the elderly. IMT may mimic the mass in which it originates. Although IMT has been defined as uncertain behaviour, it is treated surgically. We present a-65-year old man whose mass was diagnosed as IMT extending from scrotum to pelvis. The mass was independent of any surrounding anatomic structures. According to our best knowledge this is the first case in the literature that pelvic IMT was diagnosed in an elderly man and successfully treated surgically with a long term follow-up period. Aetiology of IMT is still unknown, and more studies are needed for exact continuum of IMT.

Inflammatory Myofibroblastic Tumours of the Urinary Bladder: Multi-Centre 18-Year Experience

Objective: To review a series of inflammatory myofibroblastic tumours (IMTs) of the urinary bladder in 10 hospitals in Hong Kong. Methods: A database search in the pathology archives of 10 hospitals in Hong Kong from 1995 to 2013 was performed using the key words ‘inflammatory myofibroblastic tumour', ‘inflammatory pseudotumour' and ‘spindle cell lesion'. Patient characteristics, clinical features, histological features, immunohistochemical staining results and treatment outcomes were reviewed. Results: Nine cases of IMT of the urinary bladder were retrieved. The mean age was 45.4 ± 22.8 years (range 11-78). Eight patients (88.9%) presented with haematuria and 5 patients (55.6%) had anaemia with a mean haemoglobin level of 6.8 ± 1.3 g/dl. Histologically, the majority of patients (77.8%) had a compact spindle cell pattern. Anaplastic lymphoma kinase staining was positive in 75% of cases. During a mean follow-up period of 43.4 months (range 8-94), none of them developed any local recurrence or distant metastasis. Conclusions: A high index of suspicion of IMT should be maintained for young patients presenting with bleeding bladder tumours and significant anaemia. IMTs of the urinary bladder run a benign disease course, and good prognosis can be achieved after surgical resection.

Inflammatory myofibroblastic tumor of the bladder - an unexpected case coexisting with an ovarian teratoma

Inflammatory myofibroblastic tumors (IMTs) mainly occur in children and young adults, usually in the first two decades of life. IMT-type tumors belong to neoplasms of an intermediate biologic potential with considerable rate of local recurrence and in some cases that able to create metastases. Presented case is the first IMT coexisting with the other neoplasm. In our paper we are going to present a peculiar case of an IMT of the bladder coexisting with an ovarian teratoma, and to discuss its pathogenesis, histological picture and differential diagnosis. A 19-year-old female was admitted to the Gynecological Department and during the surgery, two independent, non-adjacent tumors were found. To settle the diagnosis, a FISH examination with the ALK1 break apart probe was carried out. It confirmed the rearrangement of the chromosome 2p23. Morphologic and immunophenotypic similarities between an IMT and other malignant tumors of the bladder may lead to diagnostic errors and an unnecessary radical cystectomy as a result. The therapy of choice is only total excision of the tumor.

VIRTUAL SLIDES

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1937487606122622.

Paratesticular inflammatory myofibroblastic tumor in a pediatric patient

Although rare, paratesticular inflammatory myofibroblastic tumor (IMT) represents the second most common paratesticular mass after adenomatoid tumor and comprises roughly 6% of such lesions. Only approximately four cases have been reported in patients younger than 18 years of age. We report an incidentally discovered paratesticular IMT in a 17-year-old male successfully treated with wide excision and testis sparing. To our knowledge, no recurrence has been reported after complete excision of paratesticular IMT; however, continued follow-up is recommended.

Sarcomatoid variant of urothelial carcinoma (carcinosarcoma, spindle cell carcinoma): a review of the literature

Background. Sarcomatoid variant of urothelial carcinoma (SVUC) was added to the WHO classification in 2004. Aims. To review the literature. Materials and Method. Various internet databases were used. Result. SVUCs are rare biphasic malignant neoplasms exhibiting morphologic/immunohistochemical evidence of epithelial and mesenchymal differentiation with the presence or absence of heterologous elements. Some cases of SVUC have been associated with radiation therapy and cyclophosphamide treatment. Patients' ages range from 50 to 77 years (mean age 66). Patients tend to be younger and they more commonly presented with high-grade histology and advanced stage disease, in comparison with patients who had conventional urothelial carcinoma (CUC). Results of molecular/genetic studies strongly argue for a common monoclonal cell origin of both the epithelial and mesenchymal components in SUVC. The cancer specific survival of SVUC is poor in comparison with CUC. Radical surgical excision and chemoradiation may be associated with improved prognosis; chemoradiation as an organ preserving alternative to radical excision may be associated with improved outcome. There is no consensus opinion on the best treatment modalities for SUVC. Conclusions. SVUC is rare and is associated with inferior outcome compared with CUC. A multicentre trial of various treatment options is required. Cases of SVUC should be reported.

Inflammatory myofibroblastic tumor of the urinary bladder managed by laparoscopic partial cystectomy

Inflammatory myofibroblastic tumor of the urinary bladder is a rare mesenchymal tumor with uncertain malignant potential. It often mimics soft tissue sarcomas both clinically and radiologically. Surgical resection in the form of partial cystectomy or transurethral resection remains the mainstay of treatment. Herein we report the case of an inflammatory myofibroblastic tumor in a young girl, which was managed by laparoscopic partial cystectomy. To the best of our knowledge, this is the first reported case of laparoscopic management of an inflammatory myofibroblastic tumor of the urinary bladder.

Inflammatory myofibroblastic bladder tumor in a patient with wolf-hirschhorn syndrome

Inflammatory myofibroblastic tumor (IMT) is a rare neoplasm described in several tissues and organs including genitourinary system, lung, head, and neck. The etiology of IMT is contentious, and whether it is a postinflammatory process or a true neoplasm remains controversial. To our knowledge, we report the first reported case of IMT of urinary bladder in a pediatric patient with Wolf-Hirschhorn (WHS). We also review the literature about patients with associated neoplasia.

Low-grade myofibroblastic proliferations of the urinary bladder

CONTEXT

Myofibroblastic proliferations of the urinary bladder, which share some similarities with nodular fasciitis, were first reported in 1980. Since then, they have had several designations, the most frequently used being inflammatory myofibroblastic tumor. Based on both histopathologic and prognostic grounds, some authors prefer the term pseudosarcomatous myofibroblastic proliferation, at least for some of the proliferations. These same scientists also assimilate the so-called postoperative spindle cell nodules with the pseudosarcomatous myofibroblastic proliferations. Little is known about these low-grade myofibroblastic proliferations.

OBJECTIVES

To review the literature about low-grade myofibroblastic proliferations occurring in the urinary bladder.

DATA SOURCES

Textbooks and literature review. We obtained most of the clinicopathologic peculiarities from a patient population composed of the most-relevant, previously reported cases.

CONCLUSIONS

The low-grade myofibroblastic proliferations of the urinary bladder are rare lesions affecting males more often than they do females. The most-common signs and symptoms are hematuria and dysuria. Histopathologically, they are spindle cell proliferations in a loose myxoid stroma, even though compact proliferations or hypocellular fibrous patterns can be found. Immunohistochemistry is quite nonspecific, except for ALK-1 positivity (20%-89%). Fluorescence in situ hybridization has demonstrated clonal genetic aberrations involving the ALK gene in 50% to 60% of cases. After surgery, only 6% of patients experience local recurrence, without metastases or deaths from the disease. Malignant transformation has been reported exceptionally. These myofibroblastic proliferations are probably part of a continuum with, at one end, benign pseudosarcomatous proliferations and, at the opposite end, more-aggressive lesions. Because of the frequently indolent clinical course, aggressive treatment would be unjustified.

Urethral caruncle: a lesion related to IgG4-associated sclerosing disease?

Aims

Urethral caruncle is a benign, polypoid urethral mass that occurs almost exclusively in postmenopausal women. Despite that these lesions are routinely managed with topical medications or excision, their pathogenesis is not well understood. We investigated the possibilities of autoimmune, viral and inflammatory myofibroblastic proliferations as possible aetiologies.

Methods

In 38 patients with urethral caruncle, we utilised immunohistochemistry for immunoglobulin G (IgG) and IgG4 to assess for a potential autoimmune aetiology. Immunohistochemistry was performed in nine patients for Epstein–Barr virus, BK virus, human herpesvirus 8, human papillomavirus, adenovirus and anaplastic lymphoma kinase.

Results

Four patients (11%) showed infiltrates of ≥50 IgG4-positive plasma cells per high power field, of which all showed an IgG4 to IgG ratio greater than 40%. A statistically significant difference (p<0.01) was detected in the mean number of IgG4-positive cells (14.73 per high power field) compared with control benign urethral specimens (mean, 1.19). One patient with increased counts below this threshold had rheumatoid arthritis; none had documented autoimmune pancreatitis or other known manifestations of systemic IgG4-related sclerosing disease. All lesions showed negative reactions for the viral and inflammatory myofibroblastic markers.

Conclusions

Urethral caruncle is a benign inflammatory and fibrous polypoid urethral mass of unclear aetiology. It appears unrelated to viral infection and lacks the abnormal expression of anaplastic lymphoma kinase protein, as seen in inflammatory myofibroblastic tumours. Increased numbers of IgG4-positive plasma cells in a subset of lesions raise the possibility that some cases may be related to the autoimmune phenomena of IgG4-associated disease.

[Clinical versatility of the inflammatory pseudotumor in urology]

OBJECTIVE

The inflammatory pseudotumor is a rare lesion, having benign behavior and some histological heterogeneity that appears in the genitourinary tract. A series of urogenital inflammatory pseudotumors are reviewed with emphasis on their clinicopathological and immunohistochemical characteristics.

MATERIAL AND METHODS

A retrospective study the causistics treated between January 1981 in December 2010 was performed. It identified the cases of inflammatory pseudotumor with urogenital localization. The variables age, gender, symptoms, topography, treatment and anatomopathological and immunohistochemical characteristics of each case were analyzed.

RESULTS

A total of 8 cases of the urogenital-located inflammatory pseudotumor are described. Of these, 6 were located in the bladder, one in the kidney and one in the epididymis. Mean age of the patients was 46.75 (± 19.84) years. Tumor presentation symptoms were macroscopic hematuria, single symptom or accompanied by symptoms of the lower urinary tract and inguinoscrotal mass. In regards to treatment in the cases of bladder localization, transuretheral ± cystectomy were performed. In the case of kidney localization, treatment was made by means of pyelotomy and exeresis, and in the case of epididymis localization, simple exeresis was performed. The anatomopathological study showed inflammatory pseudotumor in every cases, having a mesenchymal and myxoid appearance, with fusiform cells of eosinophil cytoplasm, with presence of frequent inflammatory cells. The most common immunohistochemical pattern shows positivity for the muscle-specific actin (HHF-35), vimentin and negativity for protein S-100. ALK-1 was positive and 87.5% of the cases.

CONCLUSION

The inflammatory pseudotumor is a condition having good prognosis which, when there is a good histopathological and immunohistochemical diagnosis, every urologist should recognize and distinguish in order to carry out as conservative a surgical treatment as possible.

Inflammatory myofibroblastic tumor of the bladder in a 3-year-old boy

Inflammatory myofibroblastic tumor (IMT) is a rare neoplasm with unknown malignant potential that has been described in most organ systems. We present the case of a 3-year-old boy who was referred with lower urinary tract symptoms and macroscopic hematuria. An IMT was suspected after clinical, radiological, and surgical work-up, and the diagnosis was confirmed after a partial cystectomy was performed. A bladder-preserving approach is the treatment of choice, but close clinical follow-up is recommended because of the unknown biological behavior of these tumors.

Clinical utility of immunohistochemistry in the diagnoses of urinary bladder neoplasia

Urothelial carcinomas demonstrate diverse morphologic and immunologic features that frequently lead to diagnostic challenges. Recent advances have identified a number of immunohistochemical stains that, when used in the context of a panel, can be a valuable tool in properly classifying primary urothelial carcinoma and carcinomas secondarily involving the urinary bladder. In addition, new biomarkers prove helpful in the staging of bladder carcinoma. In this article, we review the clinical utility of immunohistochemistry in a series of diagnostic scenarios, including flat urothelial lesions with atypia, rare variants of urothelial carcinoma, primary adenocarcinoma versus secondary colorectal tumors, distinguishing prostate from urothelial carcinoma, and the utility of smoothelin in staging bladder carcinoma. Emphasis is placed on panels of commonly used biomarkers to establish diagnoses.

Inflammatory Myofibroblastic Bladder Tumor in a Patient with Von Recklinghausen's Syndrome

Myofibroblastic tumor, also known as inflammatory pseudotumor or pseudosarcoma, is a benign tumor with mesenchymal origin. Bladder location is very uncommon. We report the case of a 58-year-old man with a history of von Recklinghausen's disease who complained for painless macroscopic hematuria 5 months after suprapubic prostatectomy. The radiograph evaluation revealed a bladder tumor, and the pathologic examination following a transurethral resection showed inflammatory myofibroblastic tumor of the bladder. The patient finally underwent a radical cystectomy due to the uncertain pathogenesis of inflammatory myofibroblastic tumor as well as the rarity of cases published on bladder tumors in Von Recklinghausen's patients.