Inflammatory pseudotumor: a rare cause of hematuria and shock.
ABSTRACT We report the clinical, radiologic, and pathologic findings of a case of inflammatory pseudotumor in an otherwise healthy 44-year-old woman, who presented with dysuria and hematuria causing hemodynamic instability. Computed tomography revealed a 4.3-cm by 3.5-cm densely enhancing mass arising from the anterior bladder wall. Pathologic examination showed spindle-shaped cells with mild nuclear pleomorphism, rare mitotic activity, and a strong reaction to vimentin, with focal positivity to alpha-actin and S100 protein. Monokeratin, CK7, and CK20 were negative. After two transurethral resections, the patient underwent partial cystectomy.
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ABSTRACT: An inflammatory pseudotumor of the urinary bladder might cause a large, pedunculated intraluminal mass that clinically and radiologically simulates a malignant tumor. This benign lesion can easily be mistaken for a sarcoma because by light microscopy it consists of clon-gated strap cells that resemble rhabdomyoblasts. The loose texture, the myxoid background, the relative paucity of mitoses, and the absence of nuclear hyperchromasia are important histologic determinants of benignity. Smears and imprints yield voluminous tapering cells in an inflammatory background. There are no cytoplasmic cross-striations or Z-bands and the tumor cells have the ultrastructural characteristics of myofibroblasts. It is important to recognize this lesion as benign to avoid the potentially serious consequences of misdiagnosis.American Journal of Surgical Pathology 06/1985; 9(5):366-73. · 4.87 Impact Factor
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ABSTRACT: Inflammatory pseudotumor or pseudosarcomatous fibromyxoid tumor and postoperative spindle cell nodule of the bladder are unusual lesions of uncertain pathogenesis which share overlapping, if not identical, histologic features. We present our experience with 42 cases, the largest series to date, to study the etio-pathogenesis, histologic features, biologic behavior and relationship to "inflammatory myofibroblastic tumor" of childhood. Patients ranged in age from 7 to 77 years (mean 47 y) and males predominated (3.2:1). Most patients presented with hematuria (31/42). Common associations were smoking (10/30) and previous instrumentation or surgery (9/42). The clinicopathologic features of patients having or not having prior instrumentation were identical. Grossly the lesions were polypoid or nodular and involved any portion of bladder wall, most commonly the dome (9/27) and measured 1 to 10 cm (mean 4 cm). They were composed of spindled and stellate cells arranged in a myxoid background with numerous inflammatory cells. Myxoid hypocellular areas were more pronounced near the mucosal surface with greater cellularity and a fascicular arrangement in the deep aspect of the lesion. "Atypical" features included mitotic activity (0 to 20/10 HPF; mean 2/10 HPF; median 1/10 HPF; none atypical), necrosis (22/42), and extension into muscularis propria (28/32) or perivesicular fat (3/8). Lesions were positive for cytokeratin (31/33), SMA (23/34), desmin (21/35), and Alk-1 protein (12/26). FISH confirmed the Alk-1 translocation in 4/6 cases. Treatment included transurethral resection (30/42), partial cystectomy (9/42), and total cystectomy (3/42). Initial diagnostic error resulted in radiotherapy and chemotherapy in 3 patients. Follow-up was available in 28 patients. (range 3 to 93 mo; median 25 mo). Three patients developed recurrences, but none had metastases. Because the clinicopathologic features of lesions associated with and without instrumentation were similar and inseparable, we believe they are essentially the same entity, and propose the term pseudosarcomatous myofibroblastic proliferation. The preponderance of evidence which includes the extravesical growth, local recurrence, and Alk-1 gene translocation in some cases suggests perhaps a neoplastic process with limited growth potential. Even in the face of atypical histologic features (muscle invasion and necrosis) the prognosis is excellent. Despite the Alk-1 gene translocation, there continues to be sufficient evidence for regarding these as distinct from the so-called inflammatory myofibroblastic tumor of childhood.American Journal of Surgical Pathology 08/2006; 30(7):787-94. · 4.87 Impact Factor
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ABSTRACT: 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 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.Keywords: Inflammatory pseudotumor, Leiomyosarcoma, Myofibroblastic tumor, Postoperative spindle cell nodule, Spindle cell tumor, Urinary bladderModern Pathology 09/2001; 14(10):1043-1051. · 5.25 Impact Factor