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inflammatory pseudotumors ( ipts ) are rare and usually benign tumors but difficult to distinguish from malignant tumors with diagnostic techniques . they may be asymptomatic or may present with inflammatory or mass - related symptoms and signs .
ipt of different organs associated with hematopoietic stem cell transplantation ( hsct ) has been reported in only eight patients to date .
fangusaro et al . reported the first cases of ipt after hsct in two pediatric patients .
the first case was a boy aged 8 years with acute lymphocytic leukemia ( all ) who achieved remission after second - line chemotherapy .
following conditioning with high - dose cytosine arabinoside and total body irradiation ( tbi ) , he underwent allogeneic hsct .
the major early complications were acute skin and gut graft versus host disease ( gvhd ) .
after lobectomy with complete resection of the mass , patient remained in good clinical condition postoperatively .
following conditioning with carboplatin , etoposide , melphalan and tbi , he received an autologous hsct .
he first developed an esophageal stricture due to radiation therapy 2 years afterwards and underwent balloon dilatation .
the case 3 was a 23 year old woman who underwent allogeneic hsct for all .
the case 4 was a 50 year old woman who had undergone allogeneic hsct for acute myeloid leukemia ( aml ) .
conditioning was with 120 mg / kg cyclophosphamide ( cy ) and total body irradiation ( tbi ) .
after19 months , she had a sensory disturbance that involved the left side of the body . a mass detected on cranial imaging .
tumor was resected but she died from an fungal infection 5 months after ipt diagnosis .
conditioning was with busulfan 4 mg / kg / day , orally on days -7 to -4 , and cyclophosphamide ( cy ) 60 mg / kg / day , i.v . on days -3 and -2 .
hyperhydration and mesna ( 30 mg / kg , four times a day ) during cy infusion was given in order to prevent cy - induced hemorrhagic cystitis ( hc ) .
urinary system ultrasonography on day + 14 revealed a dense echogenic lesion with irregular borders like a clot .
cystoscopy doneand a mass of clot was found in the bladder on day + 17 .
after removal of clot , there was no active bleeding . during follow - up , on day + 71 a mobile echogenic mass in the bladder detected .
after 2 months later the tumor recurred but smaller than the initial lesion which was treated by tur , too .
case 7 was a japanese woman aged 36 years with chemorefractory adult t - cell leukemia ( atl ) .
there were no human leukocyte antigen - identical sibling donors , and therefore unrelated umbilical cord blood was arranged .
approximately 18 months post transplant , the patient developed a cough , slight fever and malaise .
anti - inflammatory medication improved the clinical symptoms , and the mass lesion exhibited no obvious change , while the atl remained stable .
he was diagnosed with bone marrow relapse two yr later , and after he was treated with a second course of chemotherapy , he was then referred for bone marrow transplantation from an unrelated donor . then reported slowly developing dyspnea on exertion and cough around seven months post- allogeneic hematopoietic cell transplantation .
after 8 months he was diagnosed as having an endobronchial tumor based on imaging , subtotal resection was performed and histology confirmed alk - positive submucosal spindle - shaped cells with infiltrative cells , compatible with ipt .
the clinical picture of ipts are generally varies from the more frequent benign lesions to rare tumors , which are multifocal and prone to recurrence ( table 1 ) .
coffin et al . emphasized their neoplastic nature and proposed the use of the term inflammatory myofibroblastic tumor rather than inflammatory pseudotumor .
the pathologic feature of ipts is a proliferation of spindle cells associated with a variably dense polymorphic infiltrate of mononuclear inflammatory cells ( e.g. , lymphocytes , plasma cells , histiocytes , and occasional eosinophils ) .
the lung is the most common site for involvement , but lesions may be detected on extra - pulmonary locations .
coffin et al . described 84 patients in the largest ipt series to date . but patients from his reports of ipt are not after hsct .
the presenting complaints of patients are fever , weight loss and pain , together with mass related symptoms of an inflammatory process .
the involvement sites were mostly the abdomen , retroperitoneum and pelvis , followed by head , neck , upper respiratory tract , trunk and extremities .
hepatitis c virus , human immunodeficiency virus , epstein barr virus , bacterial , fungal and mycobacterial infections have been reported to ipt . a reactive process for ipt is suggested .
maybe a result from an unusual response to noninfectious agents such as trauma or surgery . among the ipt cases in the post - hsct period , the esophageal ipt developed after the stricture in patient 2 .
all of the patients with ipt after hsct were given high - dose chemotherapy and some also received tbi .
immunosuppression and gvhd are the two factors most likely to be associated with ipts that develop after hsct
with gvhd , chronic stimulation of the cellular immune system might be the major factor .
although ipts are rare tumors , they can have a significant role on patient morbidity after hsct .
increased morbidity may derive from its site in a vital organ or from aggressive treatment given due to a misdiagnosis of malignancy .
it is difficult to distinguish ipt from malignant tumors with imaging techniques but time of the lesion is a very important data .
ipts occur earlier in the post - transplant period ranging between 3 months and 2.5 years after sct .
secondary malignancies occur as later transplant complications due to irradiation and anticancer agents , which are diagnosed at a median of 4.6 years .
so we can avoid unnecessary treatment - related complications . in summary , although ipts are rare , it will be a serious complication of hsct and seen in many organs .
unexplained inflammatory symptoms / signs or any mass lesion in the post - hsct period of a patient must be considered carefully .
inflammatory pseudotumors ( ipt ) are rare tumors that occur in various organs and tissues . 
 the clinical picture varies from the more frequent benign lesions to rare malignant tumors with distant metastases . 
 ipts associated with hematopoietic stem cell transplantation ( hsct ) is rarely reported . in this article , we review the reports of ipt after hsct . 
 we also review the possible factors involved in the pathogenesis . 
 ipt may be rare but they are a potentially serious complication of hsct 
 . a knowledge of these entities and insistence on a definitive biopsy of mass lesions in the post - hsct period can avoid unnecessary treatment such as radical surgery , chemotherapy or radiotherapy .