Inflammatory pseudotumour of the urinary bladder

Inflammatory pseudotumor of the Liver. A Report of Two Cases with Unusual Histologic Picture

Two cases of inflammatory pseudotumor (IPT) of the liver are reported. Clinical presentation was vague and aspecific. Laboratory tests and data from imaging techniques provided no specific information on the actual nature of the lesions and were misleading, suggesting a malignant lesion in one patient and a complicated hydatid cyst in the other. On gross examination, the tumors appeared yellowish ore grey-yellow in color, with a firm cut surface and well circumscribed from the surrounding parenchyma, although a true capsule was not evident. Variability in the histological pattern was also observed, even though the major finding was in both cases an admixture of lymphocytes, plasmacells, granulocytes and monocytes. Lymphocytes were immunohistochemically heterogeneous; monocytes showed in one case large hyperchromic atypical nuclei, confirming the previously, reported possibility that some cases of IPT may be mistaken for sarcomas. Further evidence is added in support of the hypothesis that some liver IPT may result from the evolution of cholangitic abscesses.

Painless Gross Haematuria

Inflammatory pseudotumour is a benign mesenchymal lesion that has distinct pathological features. Patients often present with haematuria, abdominal pain or recurrent cystitis. There are overlapping features with bladder sarcoma in presentation, age range, and size, but the pseudotumour does not metastasise. Awareness of this unusual lesion is important to prevent its misinterpretation. Complete surgical excision of the tumour mass is the treatment of choice.

Inflammatory Pseudotumor of the Spleen: A Case Report and Review of the Literature

The authors report the case of an inflammatory pseudotumor found incidentally in the spleen of a 53-year-old woman who had undergone splenectomy for the treatment of immune thrombocytopenic purpura. An ultrasound performed 2 months prior to the operation showed a spleen of normal size with no appreciable masses; however, gross examination of morselized splenic tissue removed by laparoscopic splenectomy revealed two small, well-circumscribed, white–tan nodules measuring 0.8 and 1.5 cm admixed with otherwise normal-appearing splenic parenchyma. Microscopically, these mass lesions were inflammatory pseudotumors composed of a variable mixture of polyclonal populations of mature lymphocytes and plasma cells with eosinophils, neutrophils, histiocytes, and fibrous tissue. This case represents a rare splenic lesion in our review of the world literature. Inflammatory pseudotumors of the spleen are usually solitary, often asymptomatic, rarely diagnosed prior to surgical removal, and characterized by a varied but uniformly benign histologic appearance. Recognition of this entity by clinicians and pathologists is important in definitively ruling out malignancy of the spleen.

CT Manifestations of Inflammatory Myofibroblastic Tumors (Inflammatory Pseudotumors) of the Urinary System

OBJECTIVE

The purpose of this study is to characterize the CT manifestations of inflammatory myofibroblastic tumors (IMTs) of the urinary system in eight patients.

MATERIALS AND METHODS

The CT images of eight pathologically confirmed IMTs were retrospectively reviewed. Two of the eight IMTs occurred in the kidney, and six occurred in the bladder. Seven patients underwent both unenhanced CT and contrast-enhanced CT, and one of the patients who had a bladder tumor underwent unenhanced CT only. The site, shape, size, boundary, internal structure, and enhancement pattern of the lesions were assessed.

RESULTS

The eight patients (five men and three women) whose CT images were reviewed were 18-77 years old (mean age, 53 years). Only one lesion was seen in each of the eight patients. The IMTs occurred at the renal parenchyma (n = 1), the renal pelvis (n = 1), or the bladder (n = 6). Their shape was either roundlike (n = 7) or round (n = 1), and their size ranged from 1.5 × 2.0 cm(2) to 3.7 × 5.2 cm(2). Tumor margins were smooth (n = 5) or lobulated (n = 3), and boundaries were clear (n = 5) or ill defined (n = 3). Unenhanced CT scans showed a low density (n = 4), isodensity (n = 3), or a slightly high density (n = 1). The density noted on the unenhanced CT scans was homogeneous (n = 7) or heterogeneous (n = 1). The contrast-enhanced scans showed ring enhancement (n = 3) or significantly heterogeneous enhancement (n = 4), and the type of enhancement was persistent (n = 6) or washout (n = 1).

CONCLUSION

IMTs in the urinary system commonly occur in the superior wall or the front wall of the bladder. The observation that polypoid nodules on the bladder walls show ring enhancement on contrast-enhanced CT may be valuable in the diagnostic imaging of IMTs of the urinary system.

Inflammatory pseudotumor of the urinary bladder: A case series among more than 2,000 urinary bladder tumor cases

"Inflammatory pseudotumor" (IPT) has infrequently been reported in the medical journals. A retrospective analysis was conducted among more than 2,000 bladder tumor cases from January 1999 to December 2012 looking for patients with IPT in the final diagnosis. Six patients were found with median tumor size of 3.5 cm (range: 3-8 cm); computed tomography and/or magnetic resonance imaging was used to diagnose the tumor. All patients had complete resection of the tumors. On a median follow-up of 6 years (range: 2-10 years), no recurrences for IPT have been observed in all patients. We concluded that IPT is a rare disease of the urinary bladder and should be regarded with a high degree of suspicion. Although an extensive workup may be needed for definite diagnosis, it is worth to avoid unnecessary chemoradiotherapy or radical surgeries.

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.

Pulmonary pseudoneoplasms

CONTEXT

Not uncommonly, a surgical pathologist will be requested to review excised material, with a clinical diagnosis of cancer, in which no malignancy can be identified. Often, sampling may be the issue. However, different nonneoplastic processes may mimic cancer clinically and not be recognized histologically. These are commonly referred to as pseudoneoplasms and can involve the lung, pleura, and mediastinum.

OBJECTIVE

To review the most commonly encountered pseudoneoplasms of the thoracic cavity in surgical pathology and discuss the main differential diagnosis.

DATA SOURCES

Literature and personal review of cases with focus on inflammatory pseudotumors of the lung, organizing pneumonia, nodular lymphoid hyperplasia, apical cap, round atelectasis, and sclerosing mediastinitis with its pulmonary counterpart, hyalinizing granuloma.

CONCLUSIONS

When reviewing specimens that appear nondiagnostic for malignancy, it is important to consider one of these pseudoneoplasms in the differential diagnosis as they may explain the clinical and radiologic information.

Significance of inflammatory pseudotumors in patients with a history of bladder cancer

OBJECTIVE

To study the significance of inflammatory pseudotumor (IPT) in patients with a history of bladder cancer.

METHODS

We surveyed our hospital database for patients who developed IPT during follow-up of bladder cancer. The original histologic blocks were reviewed and immunostained for vimentin, anaplastic large cell lymphoma (ALK), and pancytokeratin.

RESULTS

Between the years 1988 and 2005, a total of 809 patients were registered in the database, and 16 patients (2%) developed IPT during follow-up. All patients had initial high-grade tumor. Immunostaining for vimentin was positive in all patients, ALK was negative in all patients, and pancytokeratin positive in only 2 patients. During follow-up, 12 patients (75%) developed tumor recurrence, 9 patients (56%) tumor progression, and 6 patients (37.5%) died of bladder cancer. Median period from the finding of IPT to tumor recurrence was 16 months, to progression 7 months, and to mortality 26 months.

CONCLUSIONS

The finding of IPT in a patient with a history of bladder cancer is associated with a high risk of tumor recurrence, progression, and cancer-related mortality. Second- and possibly third-look bladder biopsies should be considered. The unique characteristics of IPT in patients with a history of bladder cancer suggest that this is a separate disease entity.

Inflammatory myofibroblastic tumor of the bladder in children: what can be expected?

Inflammatory myofibroblastic tumor of the bladder is an uncommon condition of unknown neoplastic potential. In adults the tumor is seen in association with instrumentation of the lower genitourinary tract, while in children it appears to run an idiopathic course. Its clinical and radiological presentation in children resembles sarcoma. The case of a 10-year-old girl with inflammatory myofibroblastic tumor is presented, outlining the histological and immunhistochemical features to allow differentiation between sarcomas, the most important differential diagnosis. An outcome meta-analysis of the literature identified 35 cases of inflammatory myofibroblastic tumor in the bladder of children. Conservative surgery is the strategy of choice. There is no evidence of recurrence or metastasis at a median follow up of 1.5 years.

ALK expression in pseudosarcomatous myofibroblastic proliferations of the genitourinary tract

AIMS

Pseudosarcomatous myofibroblastic proliferation of the genitourinary tract is rare and may develop after trauma or spontaneously. The aim of this study was to characterize further the clinicopathological features of these lesions and to examine their relationship to inflammatory myofibroblastic tumour (IMT).

METHODS AND RESULTS

Twenty-seven cases of pseudosarcomatous myofibroblastic proliferation were analysed. There were seven males and 20 females; median age was 37 years (range 16-88). Most lesions were from the bladder (n = 21), while others were in the urethra, vulva, vagina, rectum and retrovesical space. Median tumour size was 30 mm (range 6-120 mm). Seven cases (25%) had a history of prior trauma or surgery. Three cases recurred locally but not destructively. The tumours had fasciitis-like features including bland spindle cells with evenly distributed chromatin, admixed inflammatory cells (mainly lymphocytes) and often a myxoid stroma. Immunohistochemistry showed positivity for smooth muscle actin in 14/20 cases, keratin in 8/19, desmin in 7/20 and anaplastic lymphoma kinase (ALK) in 10/21 cases. Fluorescent in situ hybridization was performed in six ALK+ cases; all were negative for ALK gene rearrangement.

CONCLUSIONS

Pseudosarcomatous myofibroblastic proliferations of the genitourinary tract may show ALK immunopositivity but do not show consistent ALK rearrangement. Given subtle morphological differences and more consistently benign behaviour, their relationship to inflammatory myofibroblastic tumour at other sites remains uncertain.

[Myofibroblastic tumor of bladder]

The myofibroblastic tumor, is a mesenchymal benign tumor of exceptional character, being its localization but habitual it is the lung; while its appearance in the bladder, is exceptional, not existing but of 100 published cases, of this tumor type in the bladder. This tumor type that clinic and radiologics, behave as a wicked tumor. The pathological diagnosis is complex, due to its similarity with the sarcomas, being necessary to appeal to the inmunohistochemics for a I diagnose of certainty. The treatment by means of wide resection is usually enough not existing any case of metastasis at the present time at distance, neither of malignization. We present a new case of this neoplasm, carrying out a wide bibliographical revision.

So-called inflammatory myofibroblastic tumour: a proliferative lesion of fibroblastic reticulum cells?

The term inflammatory pseudotumour was originally used in a generic fashion for any lesion which simulated a neoplastic condition at a clinical, macroscopic and microscopic level but which was thought to have an inflammatory/reactive pathogenesis. In more recent times, the term has been employed in a more restrictive sense for a mass lesion characterized microscopically by the proliferation of a spindle cell component against a heavy inflammatory infiltrate of mixed composition but usually with a predominance of mature lymphocyte and plasma cells. The spindle cell component has generally been regarded as being of mesenchymal nature and having morphological and phenotypical features consistent with fibroblasts or myofibroblasts, the latter cell being clearly preferred over the former in the more resent reports. The term inflammatory myofibroblastic tumour (IMFT) is the one currently favoured, which proposes the myofibroblastic nature of the process. It is the purpose of this review to bring forth some evidence that the neoplastic spindle cell component of IMFT may be instead derived from the subtype of cells of the accessory immune system that have been variously called fibroblastic reticulum cells, myoid cells, and dictyocytes.

Anaplastic lymphoma kinase (ALK 1) staining and molecular analysis in inflammatory myofibroblastic tumours of the bladder: a preliminary clinicopathological study of nine cases and review of the literature

Inflammatory myofibroblastic tumours (IMFT) may arise at any anatomical site, including lung, soft tissues, retroperitoneum and bladder. Although morphologically similar, these lesions encompass a spectrum of entities with differing aetiology, ranging from reactive/regenerative proliferations to low-grade neoplasms with a risk of local recurrence, but no significant metastatic potential. Vesical IMFT usually presents as a polypoid mass with a pale firm cut surface and can be of considerable size, mimicking a malignant tumour clinically and radiologically. Its good outcome, however, warrants conservative surgical excision, emphasising the importance of identification and distinction from malignant tumours of the bladder that may require more radical surgery and/or adjuvant therapy. We conducted a preliminary retrospective, comparative immunocytochemical study of 20 bladder tumours, including nine IMFTs, five spindle cell (sarcomatoid) carcinomas, two rhabdomyosarcomas, two leiomyosarcomas and two neurofibromas. The results confirmed IMFT positivity for smooth muscle actin, desmin and cytokeratin in 78-89% cases, resulting in potential confusion with sarcomatoid carcinoma or leiomyosarcoma. In contrast, cytoplasmic anaplastic lymphoma kinase (ALK 1) staining was present in eight IMFT (89%), but was not seen in any other lesion examined. The ALK 1 staining was confirmed by fluorescence in situ hybridisation, with translocation of the ALK gene present in 15-60% tumour cells in four of six IMFT examined, but not in four cases of sarcomatoid carcinoma or three of leiomyosarcoma. In conclusion, ALK 1 staining may be of value in the distinction of vesical IMFT from morphologically similar entities, and often reflects ALK gene translocations in these lesions.

Inflammatory pseudotumor and sarcoma of urinary bladder: differential diagnosis and outcome in thirty-eight spindle cell neoplasms

We assessed diagnostic criteria among 38 spindle cell tumors of the urinary bladder and obtained follow-up in 36 patients. Patients comprised 28 males and 10 females aged 2.5 months to 87 years. Hematuria was the commonest presenting symptom (27 patients). After review and immunohistochemical workup, 17 patients had inflammatory pseudotumor (myofibroblastic tumor), 4 postoperative spindle cell nodule, 1 leiomyoma, 13 sarcoma (7 low-grade; 6 high-grade), and 3 carcinoma. Mean age was 38 years for pseudotumor (range 15 to 74), 65 for postoperative spindle cell nodule, 51 for sarcoma, and 76 for carcinoma. Size of pseudotumor averaged 4.4 +/- 0.7 cm (range 1.5 to 13.0), similar to sarcoma, 4.0 +/- 0.6 cm (range 0.5 to 7.0). Similar proportions of benign tumors and sarcomas had muscularis propria invasion. The criteria that best differentiated sarcoma from inflammatory pseudotumor were presence of necrosis at the tumor-detrusor muscle interface in muscle-invasive cases, and nuclear atypia. Sarcoma also had less prominent microvasculature, less variable cellularity, consistently > or =1 mitotic figure per 10 high-power fields, and predominant acute inflammation without plasma cells. p53 protein nuclear immunostaining was moderate, unlike the rare to absent staining in pseudotumors. Because all 12 sarcomas were desmin-negative, we did not call them leiomyosarcoma; they overlapped with benign tumor in epithelial, mesenchymal, and actin immunostaining. Among 12 sarcoma patients, 2 died of tumor (at 3 months). Two of four experienced tumor recurrence after partial cystectomy (2 and 26 months). No pseudotumors recurred after transurethral resection or partial cystectomy, although one patient, 5 months after transurethral resection, had histologically identical pseudotumor that the surgeon considered residual. Another patient with pseudotumor, not a candidate for tumor ablation after transurethral resection, had continued tumor growth and he died of urosepsis. In conclusion, inflammatory pseudotumor, although overlapping with sarcoma in presentation, age range, and size, does not metastasize and remains histologically distinct from low-grade sarcoma.

Inflammatory (pseudosarcomatous) myofibroblastic tumor of the urinary bladder causing acute abdominal pain

Inflammatory myofibroblastic tumor is a reactive proliferation of myofibroblasts that rarely involves the urinary bladder. The cause of inflammatory myofibroblastic tumor is unknown but may represent an initial reactive process to an infectious agent or trauma that transforms into neoplastic growth. Cases reported in children, however, often lack any preexisting bladder pathology. The authors present a case in a young child that presented as acute abdominal pain. In general, these tumors follow a benign clinical course after resection, although close monitoring is essential given the rarity of this bladder lesion.

Inflammatory (pseudosarcomatous) myofibroblastic tumor of the bladder

We present a case of inflammatory (pseudosarcomatous) myofibroblastic tumor of the bladder in a child, along with a review of the literature. The benign nature of this rare disorder needs to be recognized so that superfluous radical therapy can be avoided. The clinical features and microscopic, ultrastructural, and immunohistochemical characteristics that help to identify this entity are described. To date, 72 such cases involving the bladder have been reported in the literature including the present one.

Clonal changes in inflammatory pseudotumor of the lung: a case report

BACKGROUND

Pulmonary inflammatory pseudotumor, also known as plasma cell granuloma among many other names, is widely believed to be an inflammatory or reactive lesion rather than a neoplasm, although its pathogenesis is still controversial.

METHODS

Cytogenetic analysis was performed on a lung mass that showed typical clinical and pathologic features of inflammatory pseudotumor. Ultrastructural and immunohistochemical studies were performed in addition to routine histologic examination.

RESULTS

Cytogenetic study of the lesion revealed clonal anomalies of t(1;2)(q21;p23) and del(4)(q27). The patient, a 30-year-old woman, presented with an asymptomatic but enlarging right lower lobe mass for which partial right lower lobectomy was performed. The lung mass was well circumscribed radiographically and grossly. Microscopically, it was characterized by a loosely arranged spindle cell proliferation with prominent plasma cell infiltration. Fibroblastic and myofibroblastic differentiation of the spindle cells was demonstrated by ultrastructural and immunohistochemical studies.

CONCLUSION

To the authors' knowledge, this is the first report of clonal cytogenetic changes in a clinically and pathologically typical case of inflammatory pseudotumor in the lung. This finding suggests that pulmonary inflammatory pseudotumor might be a true neoplasm rather than a purely inflammatory or reactive lesion.

Pseudosarcomatous myofibroblastic proliferation of the bladder: report of 2 cases and literature review

We report 2 cases of pseudosarcomatous myofibroblastic proliferations of the bladder unrelated to urological trauma. To our knowledge, these cases represent the longest followup (12 and 19 years, respectively) reported in the literature, which confirms the long-term benign nature of an entity that may be clinically and even pathologically mistaken as malignancy. A review of the literature revealed a female predominance (3:1), 50% of the cases manifested in the first 2 decades of life and mean age was significantly lower in male patients (p < 0.005). These facts suggest the existence of a hormonal factor in the pathogenesis of this entity. A predilection for fundus, and the posterior and lateral walls also is demonstrated. In light of the complex embryogenesis of the cloacal territory, it could be hypothesized that this lesion arises from embryonal mesenchymal remnants of the endodermally derived urinary tract.

Primary mesenchymal tumors of the urinary bladder. A histological and immunohistochemical study of 30 cases

The light microscopic and immunohistochemical features of 30 primary mesenchymal neoplasms of the urinary bladder are reported. Half of the cases represented smooth and striated muscle tumors (five leiomyomas, seven leiomyosarcomas including epithelioid and myxoid subtypes, one rhabdomyoma, one embryonal rhabdomyosarcoma and one alveolar rhabdomyosarcoma). One third of the tumors were of fibrohistiocytic origin (one fibrous histiocytoma and eight malignant fibrous histiocytomas including fascicular and storiform, inflammatory and pleomorphic subtypes). In addition, a malignant epithelioid schwannoma, a round cell liposarcoma, two hemangiomas and two mixed mesodermal tumors were observed. The morphology of the vesical mesenchymal tumors was identical to that of their counterparts known to occur in other sites, particularly in the soft tissue. Muscle-specific actin, alpha-1-antichymotrypsin, S-100-protein and neuron-specific enolase proved to be useful and reliable immunomarkers for differential diagnosis of poorly differentiated leio- and rhabdomyosarcomas, malignant fibrous histiocytomas and malignant schwannomas. Since some tumors coexpressed several classes of intermediate filaments, diagnostic immunocytochemistry should only be used considering a larger panel of antibodies and in close correlation with the histological and cytological features of the neoplasms.

Pseudomalignant spindle cell proliferations of the urinary bladder

Twelve cases of polypoid, nonrecurrent, pseudomalignant spindle cell proliferations of the urinary bladder (eight women and four men) were analyzed. Two patients had a simultaneous urinary bladder carcinoma. The lesions were characterized by proliferating spindle- or strap-shaped cells, which on electron microscopic examination (performed in all 12 cases) revealed characteristics of fibroblasts and myofibroblasts. The cells showed immunoreactivity for vimentin in all cases, for alpha-smooth muscle-specific and muscle-specific actin in six cases, for cytokeratins in five cases, and for CD 34 in one case. No immunoreactivity was observed for desmin, myoglobin, epithelial membrane antigen, S-100 protein, endothelial cell antigen (H and Y), CD 68, or factor VIII RAG. Immunoreactivity for Ki-67 and proliferating cell nuclear antigen was detected in up to 30% of the spindle cell nuclei. The static cytometric DNA analysis revealed a diploid, or in two cases a hyperdiploid, stem cell line. An awareness of this type of spindle cell lesion and its immunophenotypic characteristics and diversity is of importance to avoid an erroneous diagnosis of spindle cell sarcoma (in particular leiomyosarcoma and embryonal rhabdomyosarcoma) or spindle cell carcinoma.

Pseudosarcomatous fibromyxoid tumor of the urinary bladder and prostate: immunohistochemical, ultrastructural, and DNA flow cytometric analyses of nine cases

Pseudosarcomatous fibromyxoid tumor of the genitourinary tract is a rare pathologic entity of hitherto unknown etiology that, because of the cellular pleomorphism and the infiltrative nature of the lesion, may be mistakenly diagnosed as sarcomatoid carcinoma or sarcoma. We retrospectively studied nine pseudosarcomatous fibromyxoid tumors involving the bladder and prostate to define characteristic parameters that may allow for accurate diagnosis. The study patients included four men and five women with a mean age of 48.7 years. Histologic analysis revealed myxoid lesions with a proliferation of spindle fibroblastic cells in a background of granulation tissue-type vascularity and inflammatory cells. Mitoses were infrequent and no atypical forms were found. Immunostaining was positive for vimentin and smooth muscle actin, and negative for S-100 protein, desmin, myoglobin, and keratin. Ultrastructurally, the lesion displayed fibroblastic and myofibroblastic cell features. Flow cytometric DNA content analysis revealed uniform DNA diploidy and a low S-phase fraction. All patients were alive and well with no evidence of disease after a mean follow-up of 4.8 years. In contrast, the sarcomatoid carcinomas and sarcomas of the urinary bladder and prostate that were used as controls occurred in older patients and had more frequent mitoses with atypical forms, tumor-type necrosis, and different immunostaining profiles; they were preponderantly aneuploid or diploid with high S-phase fraction. Awareness of the clinicopathologic and biologic characteristics of these lesions is necessary to ensure their accurate diagnosis and to prevent unnecessary radical therapy.