- Email: [email protected]
Bilateral Infiltrating Renal Inflammatory Pseudotumor Responsive to Corticosteroid Therapy
CASE REPORTS Bilateral Infiltrating Renal Inflammatory Pseudotumor Responsive to Corticosteroid Therapy Yanjun Ma, MD, PhD,1 Arthur W. Zieske, MD,2 and Andrew Z. Fenves, MD3 Inflammatory pseudotumor (IPT) is a quasi-neoplastic lesion that most commonly involves the lung, but has been shown to occur in nearly every tissue type. Renal involvement is very uncommon. We report the second case of IPT ever published presenting as bilateral infiltrating renal masses. Although most renal IPTs were treated with nephrectomy, our patient was managed successfully with conservative steroid treatment, thereby avoiding the alternative of dialysis or kidney transplantation. Am J Kidney Dis 51:116-120. © 2007 by the National Kidney Foundation, Inc. INDEX WORDS: Inflammatory pseudotumor; renal mass; steroid.
I
nflammatory pseudotumor (IPT) refers to any lesion that simulates a neoplastic process at a clinical, imaging, and sometimes histological level, but is believed to be the result of an aberrant or exaggerated inflammatory response to tissue injury. The first large series of IPT was reported by Bahadori and Liebow1 in 1973, in which 40 cases of pulmonary IPT were identified as the most commonly isolated primary tumor of the lung in children younger than 16 years. It was considered to be reactive or inflammatory in nature. However, this characterization of IPT was challenged by the recent clinical demonstration of local recurrence and acquired chromosomal abnormalities.2,3 IPT is now considered a generally benign neoplasm with some potential for malignant transformation. We describe a rare case of bilateral and diffusely infiltrating renal IPT for which radiological images were highly suggestive of lymphoma. Because of bilateral renal involvement, our patient was treated conservatively with high-dose steroid therapy. She responded well, and after 3
1 From the Departments of Internal Medicine and 2Pathology and 3Division of Nephrology, Baylor University Medical Center, Dallas, TX. Received June 28, 2007. Accepted in revised form August 7, 2007. Originally published online as doi: 10.1053/j.ajkd.2007.08.028 on November 30, 2007. Address correspondence to Yanjun Ma, MD, PhD, Department of Internal Medicine, Baylor University Medical Center at Dallas, 3500 Gaston Ave, Dallas, TX 75246. E-mail: [email protected] © 2007 by the National Kidney Foundation, Inc. 0272-6386/07/5101-0015$34.00/0 doi:10.1053/j.ajkd.2007.08.028
116
months of therapy, the infiltrating tumors were almost completely eliminated, shown by computed tomography (CT) imaging (Figs 1 and 2). CASE REPORT Our patient is a 42-year-old woman with a medical history of hypertension and chronic seasonal sinusitis. Her sinusitis became resistant to oral antibiotic treatment in winter 2004. She developed angioedema secondary to sinusitis that required nasal sinus polypectomy and intravenous vancomycin plus ceftriaxone. After 3 weeks of antibiotic treatment, she developed an allergic reaction to both medications, as well as drug-induced pustular psoriasis. The latter was confirmed by skin biopsy and treated with oral cyclosporine A for 2 months. Her skin lesions resolved completely with cyclosporine therapy. Two months after discontinuation of cyclosporine A treatment, the patient started experiencing intermittent abdominal pain, nausea, fatigue, and weight loss. A CT scan obtained at an outside hospital suggested bilateral renal masses. The patient was then transferred to our hospital. She also experienced intermittent fevers up to 101°F during her hospital stay before treatment was started. During the course of the next 6 months, the patient was admitted multiple times for diagnostic biopsies, imaging, and other studies. Her serum creatinine level remained stable in the range of 1.0 to 1.2 mg/dL (76.25 to 91.5 mol/L). She also had an increased erythrocyte sedimentation rate that fluctuated from 38 to 130 mm/h, normocytic and normochromic anemia of chronic disease that responded to erythropoietin treatment, proteinuria with protein of 0.48 g/d, increased uric acid level of 6.8 mg/dL (404 mol/L), and polyclonal hypergammaglobulinemia of 1.8 g/dL. Results of basic autoimmune screening for antinuclear antibodies, antineutrophil cytoplasmic antibodies, and rheumatic factor were negative. A repeated CT scan showed bilateral infiltrating masses encasing both kidneys that continued to grow during the initial 3 months of presentation before treatment was started (compare Fig 1A with 1B). The infiltrating mass in the right kidney obstructed the right ureter, causing hydronephrosis of the upper half of the kidney (Fig 1A and B). The mass lesion had completely replaced the lower half of
American Journal of Kidney Diseases, Vol 51, No 1 (January), 2008: pp 116-120
Bilateral Renal Inflammatory Pseudotumor
117
Figure 1. Computed tomographic images of the upper pole of bilateral kidneys with contrast before and after treatment. (A) Axial section of bilateral kidneys in July 2006, the patient’s initial presentation. (B) Bilateral kidneys 3 months later (October 2006), or 2 months before oral steroid therapy was started, (C) 1 month after high-dose prednisone (60 mg/d) treatment, and (D) 3 months after oral steroid treatment.
the right kidney (Fig 2A), whereas the left kidney was almost completely infiltrated by the tumor. The extensive infiltrating mass extended beneath the left hemidiaphragm and along both ureters, occupying much of the left and lower right perinephric spaces. Liver, gallbladder, pancreas, and urinary bladder were all normal. Enlarged lymph nodes in the left periaortic region were also observed. An initial needle aspiration of the renal mass was negative for lymphoma. Subsequently, needle core biopsy and then laparoscopic direct biopsy of the bilateral renal lesions were performed to increase the chance of identifying a malignancy. No malignant cells were identified by using either flow cytometry, cytogenetics, or histological examination with all biopsy samples. Bone marrow biopsy was also performed, which showed normal cellularity and was negative for either lymphoid or myeloid malignant cells. On one of the initial renal core biopsies, normal kidney parenchyma was replaced by sheets of
active-appearing mononuclear cells accompanied by frequent eosinophils. Glomerular structures were spared, but there was ischemic wrinkling, endothelial hypercellularity, and marked tubular damage (Fig 2C). In other core biopsy samples, the renal parenchyma was completely replaced by densely hyalinized fibrous tissue. The infiltrate contained a mixture of inflammatory cells, including lymphocytes, plasma cells, eosinophils, neutrophils, and histiocytes. Admixed with these inflammatory cells were dense collagen bundles. Overall, the subsequent perinephric mass showed a florid sclerosing fibroinflammatory lesion (Fig 2D). Because of the bilateral and infiltrating nature of the renal lesions and the well-preserved renal function (measured creatinine clearance, 77.6 mL/min [1.2 mL/s]), surgical intervention was ill advised. High-dose oral steroid treatment was started because there was anecdotal evidence of renal IPT responding to steroid treatment.4,5 After treatment
118
Ma, Zieske, and Fenves
Figure 2. (A, B) Computed tomographic (CT) images of the lower pole of bilateral kidneys with contrast before and after treatment and (C, D) histological characteristics of the renal lesion. (Hematoxylin and eosin stain.) (A) Two months before oral steroid therapy was started. (B) Three months after oral steroid treatment, the bilateral infiltrating renal masses almost completely resolved on CT imaging. (C) Renal core biopsy specimen shows florid interstitial nephritis with prominent eosinophils and fibrosis. (Left) A glomerulus, and (right) a damaged tubule. (Original magnification ⫻40.) (D) The infiltrative mass surrounding the kidney shows a florid sclerosing fibroinflammatory picture. (Original magnification ⫻10.)
with 60, 40, and then 30 mg/d of oral prednisone, each for 1 month, erythrocyte sedimentation rate decreased to 5 mm/h, uric acid level decreased to 5.9 mg/dL (350.9 mol/L), gammaglobulin level decreased to 1.0 g/dL, creatinine clearance increased to 93 mL/min (1.55 mL/s), and 24-hour urine protein excretion decreased to 0.16 g. A repeated CT scan of the abdomen showed almost complete resolution of the bilateral infiltrating masses (Figs 1D and 2B). Hydronephrosis of the right kidney also resolved (Fig 1D).
DISCUSSION
We identified 43 cases of renal IPT since it was first reported in 1972.6 There was no significant sex difference in the incidence of this condition. Of the 43 cases, all except 1 patient presented with a solitary mass of a unilateral kidney, and all except 2 patients were treated with total or partial nephrectomy. Our patient is the second
ever reported case of renal IPT presenting as bilateral and diffusely infiltrating lesions imitating renal lymphoma. The only previously reported case was a patient with a recurrent history of systemic IPT involving the common bile duct; inguinal, axillary, submandibular, and cervical lymph nodes; pancreatic tail; and both kidneys. Conversely, the bilateral renal masses were the first presentation of pseudotumor in our patient, while no other organ was involved. In 19% of patients, IPT was accompanied by some kind of systemic symptoms, including fever, malaise, weight loss, thrombocytosis, hypergammaglobulinemia, or increased erythrocyte sedimentation rate.7 All these symptoms and clinical findings were present in our patient and
Bilateral Renal Inflammatory Pseudotumor
resolved after oral steroid therapy. Renal IPT usually is treated by nephrectomy because it usually presents as a solitary mass that is radiologically indistinguishable from renal cell carcinoma. The diagnosis usually is reached pathologically only after surgery. Of all 43 reported cases, only 2 patients were treated with oral steroid therapy.4,5 Because of the unique characteristic of bilateral renal involvement and the wellpreserved renal function of our patient, conservative therapy was chosen instead of surgical resection. No local recurrence or malignant transformation was reported when IPT involved only the kidney, although most renal IPTs (95%) were treated with nephrectomy. Increased experience showed that IPT of other sites can run an aggressive clinical course and exhibit morphological and molecular abnormalities more in keeping with a neoplastic than pure inflammatory process.8,9 The overall cure rate for patients with IPT is about 67%, with 22% experiencing local recurrences; 2.5%, distant metastases; and a mortality rate of around 1.8%.10 IPT is a rare disease of obscure cause. Human herpesvirus-8 viral sequences were detected by using polymerase chain reaction in a small number of patients, and its viral protein was expressed in the spindle cell nuclei in inflammatory myofibroblastic tumor, a subtype of IPT.11-13 Exposure to immunosuppressants also was postulated as a possible cause of IPT. There were reports of IPT in patients receiving organ or bone marrow transplants.14-17 Our patient received 2 months of cyclosporine A treatment. There may also be a cause-and-effect link between autoimmune diseases and IPT. Nonaka et al7 showed that myofibroblasts in the infiltrate of IPT may be of accessory immune system origin, eg, myoid cells or fibroblastic reticulum cells. Pancreatic IPT also was associated with autoimmune pancreatitis.18,19 Our patient developed an allergy to vancomycin and ceftriaxone, as well as druginduced pustular psoriasis, about 4 months before the development of IPT. IPT of the kidney presenting as bilateral infiltrating lesions is an extremely rare occurrence. High-dose steroid therapy may offer a viable treatment alternative for these patients to preserve renal function and avoid dialysis and/or transplantation. Close outpatient follow-up will
119
be required to monitor local recurrence or malignant transformation. ACKNOWLEDGEMENTS We thank Dr Christopher D.M. Fletcher at Brigham and Women’s Hospital for reviewing our patient’s pathology slides and confirming our diagnosis of IPT. Support: None. Financial Disclosure: None.
REFERENCES 1. Bahadori M, Liebow AA: Plasma cell granuloma of the lung. Cancer 31:191-208, 1973 2. Snyder CS, Dell’Aquila M, Haghighi P, Baergen RN, Suh YK, Yi ES: Clonal changes in inflammatory pseudotumor of the lung: A case report. Cancer 76:1545-1549, 1995 3. Biselli R, Ferlini C, Fattorossi A, Boldrini R, Bosman C: Inflammatory myofibroblastic tumor (inflammatory pseudotumor): DNA flow cytometric analysis of nine pediatric cases. Cancer 77:778-784, 1996 4. Williams ME, Longmaid HE, Trey G, Federman M, Crosson AW: Renal failure resulting from infiltration by inflammatory myofibroblastic tumor responsive to corticosteroid therapy. Am J Kidney Dis 31:E5, 1998 5. Kobayashi TK, Ueda M, Nishino T, Kushima R, Kato K, Katsumori T: Inflammatory pseudotumor of the kidney: Report of a case with fine needle aspiration cytology. Acta Cytol 44:478-480, 2000 6. Davides KC, Johnson SH III, Marshall M Jr, Price SE Jr, Stavrides A: Plasma cell granuloma of the renal pelvis. J Urol 107:938-939, 1972 7. Nonaka D, Birbe R, Rosai J: So-called inflammatory myofibroblastic tumour: A proliferative lesion of fibroblastic reticulum cells? Histopathology 46:604-613, 2005 8. Montgomery EA, Shuster DD, Burkart AL, et al: Inflammatory myofibroblastic tumors of the urinary tract: A clinicopathologic study of 46 cases, including a malignant example inflammatory fibrosarcoma and a subset associated with high-grade urothelial carcinoma. Am J Surg Pathol 30:1502-1512, 2006 9. Zavaglia C., Barberies M, Gelosa F, et al: Inflammatory pseudotumour of the liver with malignant transformation. Report of two cases. Ital J Gastroenterol 28:152-159, 1996 10. Coffin CM, Watterson J, Priest JR, Dehner LP: Extrapulmonary inflammatory myofibroblastic tumor (inflammatory pseudotumor). A clinicopathologic and immunohistochemical study of 84 cases. Am J Surg Pathol 19:859-872, 1995 11. Ding Y, Saylors RL, Brown H, et al: Pulmonary inflammatory pseudotumor with HHV-8. Am J Surg Pathol 26:1089-1091, 2002 12. Gomez-Roman JJ, Sanchez-Velasco P, Ocejo-Vinyals G, Hernandez-Nieto E, Leyva-Cobian F, Val-Berbal JF: Human herpesvirus-8 genes are expressed in pulmonary inflammatory myofibroblastic tumor (inflammatory pseudotumor). Am J Surg Pathol 25:624-629, 2001 13. Gomez-Roman JJ, Ocejo-Vinyals G, Sanchez-Velasco P, Nieto EH, Leyva-Cobian F, Val-Bernal JF: Presence of human herpesvirus-8 DNA sequences and overexpression of
120 human IL-6 and cyclin D1 in inflammatory myofibroblastic tumor (inflammatory pseudotumor). Lab Invest 80: 1121-1126, 2000 14. Fangusaro J, Klopfenstein K, Groner J, Hammond S, Altura RA: Inflammatory myofibroblastic tumor following hematopoietic stem cell transplantation: Report of two pediatric cases. Bone Marrow Transplant 33:103-107, 2004 15. Remberger K, Weiss M, Gokel JM, Landgraf R, Illner WD, Land W: Inflammatory pseudotumor of the pancreas with persistent hyper-insulinemia and hypoglycemia following long-term pancreatic transplantation. Verh Dtsch Ges Pathol 71:328-332, 1987 16. Lykavieris P, Fabre M, Waguet J, Bernard O: Inflammatory pseudotumor after liver transplantation. J Pediatr Gastroenterol Nutr 31:309-312, 2000
Ma, Zieske, and Fenves 17. Lykavieris P, Fabre M, Pariente D, Lezeau YM, Debray D: Clostridium difficile colitis associated with inflammatory pseudotumor in a liver transplant recipient. Pediatr Transplant 7:76-79, 2003 18. Mizukami H, Yajima N, Wada R, et al: Pancreatic malignant fibrous histiocytoma, inflammatory myofibroblastic tumor and inflammatory pseudotumor related to autoimmune pancreatitis: Characterization and differential diagnosis. Virchows Arch 448:552-560, 2006 19. Esposito I, Bergmann F, Penzel R, et al: Oligoclonal T-cell populations in an inflammatory pseudotumor of the pancreas possibly related to autoimmune pancreatitis: An immunohistochemical and molecular analysis. Virchows Arch 444:119-126, 2004
I
nflammatory pseudotumor (IPT) refers to any lesion that simulates a neoplastic process at a clinical, imaging, and sometimes histological level, but is believed to be the result of an aberrant or exaggerated inflammatory response to tissue injury. The first large series of IPT was reported by Bahadori and Liebow1 in 1973, in which 40 cases of pulmonary IPT were identified as the most commonly isolated primary tumor of the lung in children younger than 16 years. It was considered to be reactive or inflammatory in nature. However, this characterization of IPT was challenged by the recent clinical demonstration of local recurrence and acquired chromosomal abnormalities.2,3 IPT is now considered a generally benign neoplasm with some potential for malignant transformation. We describe a rare case of bilateral and diffusely infiltrating renal IPT for which radiological images were highly suggestive of lymphoma. Because of bilateral renal involvement, our patient was treated conservatively with high-dose steroid therapy. She responded well, and after 3
1 From the Departments of Internal Medicine and 2Pathology and 3Division of Nephrology, Baylor University Medical Center, Dallas, TX. Received June 28, 2007. Accepted in revised form August 7, 2007. Originally published online as doi: 10.1053/j.ajkd.2007.08.028 on November 30, 2007. Address correspondence to Yanjun Ma, MD, PhD, Department of Internal Medicine, Baylor University Medical Center at Dallas, 3500 Gaston Ave, Dallas, TX 75246. E-mail: [email protected] © 2007 by the National Kidney Foundation, Inc. 0272-6386/07/5101-0015$34.00/0 doi:10.1053/j.ajkd.2007.08.028
116
months of therapy, the infiltrating tumors were almost completely eliminated, shown by computed tomography (CT) imaging (Figs 1 and 2). CASE REPORT Our patient is a 42-year-old woman with a medical history of hypertension and chronic seasonal sinusitis. Her sinusitis became resistant to oral antibiotic treatment in winter 2004. She developed angioedema secondary to sinusitis that required nasal sinus polypectomy and intravenous vancomycin plus ceftriaxone. After 3 weeks of antibiotic treatment, she developed an allergic reaction to both medications, as well as drug-induced pustular psoriasis. The latter was confirmed by skin biopsy and treated with oral cyclosporine A for 2 months. Her skin lesions resolved completely with cyclosporine therapy. Two months after discontinuation of cyclosporine A treatment, the patient started experiencing intermittent abdominal pain, nausea, fatigue, and weight loss. A CT scan obtained at an outside hospital suggested bilateral renal masses. The patient was then transferred to our hospital. She also experienced intermittent fevers up to 101°F during her hospital stay before treatment was started. During the course of the next 6 months, the patient was admitted multiple times for diagnostic biopsies, imaging, and other studies. Her serum creatinine level remained stable in the range of 1.0 to 1.2 mg/dL (76.25 to 91.5 mol/L). She also had an increased erythrocyte sedimentation rate that fluctuated from 38 to 130 mm/h, normocytic and normochromic anemia of chronic disease that responded to erythropoietin treatment, proteinuria with protein of 0.48 g/d, increased uric acid level of 6.8 mg/dL (404 mol/L), and polyclonal hypergammaglobulinemia of 1.8 g/dL. Results of basic autoimmune screening for antinuclear antibodies, antineutrophil cytoplasmic antibodies, and rheumatic factor were negative. A repeated CT scan showed bilateral infiltrating masses encasing both kidneys that continued to grow during the initial 3 months of presentation before treatment was started (compare Fig 1A with 1B). The infiltrating mass in the right kidney obstructed the right ureter, causing hydronephrosis of the upper half of the kidney (Fig 1A and B). The mass lesion had completely replaced the lower half of
American Journal of Kidney Diseases, Vol 51, No 1 (January), 2008: pp 116-120
Bilateral Renal Inflammatory Pseudotumor
117
Figure 1. Computed tomographic images of the upper pole of bilateral kidneys with contrast before and after treatment. (A) Axial section of bilateral kidneys in July 2006, the patient’s initial presentation. (B) Bilateral kidneys 3 months later (October 2006), or 2 months before oral steroid therapy was started, (C) 1 month after high-dose prednisone (60 mg/d) treatment, and (D) 3 months after oral steroid treatment.
the right kidney (Fig 2A), whereas the left kidney was almost completely infiltrated by the tumor. The extensive infiltrating mass extended beneath the left hemidiaphragm and along both ureters, occupying much of the left and lower right perinephric spaces. Liver, gallbladder, pancreas, and urinary bladder were all normal. Enlarged lymph nodes in the left periaortic region were also observed. An initial needle aspiration of the renal mass was negative for lymphoma. Subsequently, needle core biopsy and then laparoscopic direct biopsy of the bilateral renal lesions were performed to increase the chance of identifying a malignancy. No malignant cells were identified by using either flow cytometry, cytogenetics, or histological examination with all biopsy samples. Bone marrow biopsy was also performed, which showed normal cellularity and was negative for either lymphoid or myeloid malignant cells. On one of the initial renal core biopsies, normal kidney parenchyma was replaced by sheets of
active-appearing mononuclear cells accompanied by frequent eosinophils. Glomerular structures were spared, but there was ischemic wrinkling, endothelial hypercellularity, and marked tubular damage (Fig 2C). In other core biopsy samples, the renal parenchyma was completely replaced by densely hyalinized fibrous tissue. The infiltrate contained a mixture of inflammatory cells, including lymphocytes, plasma cells, eosinophils, neutrophils, and histiocytes. Admixed with these inflammatory cells were dense collagen bundles. Overall, the subsequent perinephric mass showed a florid sclerosing fibroinflammatory lesion (Fig 2D). Because of the bilateral and infiltrating nature of the renal lesions and the well-preserved renal function (measured creatinine clearance, 77.6 mL/min [1.2 mL/s]), surgical intervention was ill advised. High-dose oral steroid treatment was started because there was anecdotal evidence of renal IPT responding to steroid treatment.4,5 After treatment
118
Ma, Zieske, and Fenves
Figure 2. (A, B) Computed tomographic (CT) images of the lower pole of bilateral kidneys with contrast before and after treatment and (C, D) histological characteristics of the renal lesion. (Hematoxylin and eosin stain.) (A) Two months before oral steroid therapy was started. (B) Three months after oral steroid treatment, the bilateral infiltrating renal masses almost completely resolved on CT imaging. (C) Renal core biopsy specimen shows florid interstitial nephritis with prominent eosinophils and fibrosis. (Left) A glomerulus, and (right) a damaged tubule. (Original magnification ⫻40.) (D) The infiltrative mass surrounding the kidney shows a florid sclerosing fibroinflammatory picture. (Original magnification ⫻10.)
with 60, 40, and then 30 mg/d of oral prednisone, each for 1 month, erythrocyte sedimentation rate decreased to 5 mm/h, uric acid level decreased to 5.9 mg/dL (350.9 mol/L), gammaglobulin level decreased to 1.0 g/dL, creatinine clearance increased to 93 mL/min (1.55 mL/s), and 24-hour urine protein excretion decreased to 0.16 g. A repeated CT scan of the abdomen showed almost complete resolution of the bilateral infiltrating masses (Figs 1D and 2B). Hydronephrosis of the right kidney also resolved (Fig 1D).
DISCUSSION
We identified 43 cases of renal IPT since it was first reported in 1972.6 There was no significant sex difference in the incidence of this condition. Of the 43 cases, all except 1 patient presented with a solitary mass of a unilateral kidney, and all except 2 patients were treated with total or partial nephrectomy. Our patient is the second
ever reported case of renal IPT presenting as bilateral and diffusely infiltrating lesions imitating renal lymphoma. The only previously reported case was a patient with a recurrent history of systemic IPT involving the common bile duct; inguinal, axillary, submandibular, and cervical lymph nodes; pancreatic tail; and both kidneys. Conversely, the bilateral renal masses were the first presentation of pseudotumor in our patient, while no other organ was involved. In 19% of patients, IPT was accompanied by some kind of systemic symptoms, including fever, malaise, weight loss, thrombocytosis, hypergammaglobulinemia, or increased erythrocyte sedimentation rate.7 All these symptoms and clinical findings were present in our patient and
Bilateral Renal Inflammatory Pseudotumor
resolved after oral steroid therapy. Renal IPT usually is treated by nephrectomy because it usually presents as a solitary mass that is radiologically indistinguishable from renal cell carcinoma. The diagnosis usually is reached pathologically only after surgery. Of all 43 reported cases, only 2 patients were treated with oral steroid therapy.4,5 Because of the unique characteristic of bilateral renal involvement and the wellpreserved renal function of our patient, conservative therapy was chosen instead of surgical resection. No local recurrence or malignant transformation was reported when IPT involved only the kidney, although most renal IPTs (95%) were treated with nephrectomy. Increased experience showed that IPT of other sites can run an aggressive clinical course and exhibit morphological and molecular abnormalities more in keeping with a neoplastic than pure inflammatory process.8,9 The overall cure rate for patients with IPT is about 67%, with 22% experiencing local recurrences; 2.5%, distant metastases; and a mortality rate of around 1.8%.10 IPT is a rare disease of obscure cause. Human herpesvirus-8 viral sequences were detected by using polymerase chain reaction in a small number of patients, and its viral protein was expressed in the spindle cell nuclei in inflammatory myofibroblastic tumor, a subtype of IPT.11-13 Exposure to immunosuppressants also was postulated as a possible cause of IPT. There were reports of IPT in patients receiving organ or bone marrow transplants.14-17 Our patient received 2 months of cyclosporine A treatment. There may also be a cause-and-effect link between autoimmune diseases and IPT. Nonaka et al7 showed that myofibroblasts in the infiltrate of IPT may be of accessory immune system origin, eg, myoid cells or fibroblastic reticulum cells. Pancreatic IPT also was associated with autoimmune pancreatitis.18,19 Our patient developed an allergy to vancomycin and ceftriaxone, as well as druginduced pustular psoriasis, about 4 months before the development of IPT. IPT of the kidney presenting as bilateral infiltrating lesions is an extremely rare occurrence. High-dose steroid therapy may offer a viable treatment alternative for these patients to preserve renal function and avoid dialysis and/or transplantation. Close outpatient follow-up will
119
be required to monitor local recurrence or malignant transformation. ACKNOWLEDGEMENTS We thank Dr Christopher D.M. Fletcher at Brigham and Women’s Hospital for reviewing our patient’s pathology slides and confirming our diagnosis of IPT. Support: None. Financial Disclosure: None.
REFERENCES 1. Bahadori M, Liebow AA: Plasma cell granuloma of the lung. Cancer 31:191-208, 1973 2. Snyder CS, Dell’Aquila M, Haghighi P, Baergen RN, Suh YK, Yi ES: Clonal changes in inflammatory pseudotumor of the lung: A case report. Cancer 76:1545-1549, 1995 3. Biselli R, Ferlini C, Fattorossi A, Boldrini R, Bosman C: Inflammatory myofibroblastic tumor (inflammatory pseudotumor): DNA flow cytometric analysis of nine pediatric cases. Cancer 77:778-784, 1996 4. Williams ME, Longmaid HE, Trey G, Federman M, Crosson AW: Renal failure resulting from infiltration by inflammatory myofibroblastic tumor responsive to corticosteroid therapy. Am J Kidney Dis 31:E5, 1998 5. Kobayashi TK, Ueda M, Nishino T, Kushima R, Kato K, Katsumori T: Inflammatory pseudotumor of the kidney: Report of a case with fine needle aspiration cytology. Acta Cytol 44:478-480, 2000 6. Davides KC, Johnson SH III, Marshall M Jr, Price SE Jr, Stavrides A: Plasma cell granuloma of the renal pelvis. J Urol 107:938-939, 1972 7. Nonaka D, Birbe R, Rosai J: So-called inflammatory myofibroblastic tumour: A proliferative lesion of fibroblastic reticulum cells? Histopathology 46:604-613, 2005 8. Montgomery EA, Shuster DD, Burkart AL, et al: Inflammatory myofibroblastic tumors of the urinary tract: A clinicopathologic study of 46 cases, including a malignant example inflammatory fibrosarcoma and a subset associated with high-grade urothelial carcinoma. Am J Surg Pathol 30:1502-1512, 2006 9. Zavaglia C., Barberies M, Gelosa F, et al: Inflammatory pseudotumour of the liver with malignant transformation. Report of two cases. Ital J Gastroenterol 28:152-159, 1996 10. Coffin CM, Watterson J, Priest JR, Dehner LP: Extrapulmonary inflammatory myofibroblastic tumor (inflammatory pseudotumor). A clinicopathologic and immunohistochemical study of 84 cases. Am J Surg Pathol 19:859-872, 1995 11. Ding Y, Saylors RL, Brown H, et al: Pulmonary inflammatory pseudotumor with HHV-8. Am J Surg Pathol 26:1089-1091, 2002 12. Gomez-Roman JJ, Sanchez-Velasco P, Ocejo-Vinyals G, Hernandez-Nieto E, Leyva-Cobian F, Val-Berbal JF: Human herpesvirus-8 genes are expressed in pulmonary inflammatory myofibroblastic tumor (inflammatory pseudotumor). Am J Surg Pathol 25:624-629, 2001 13. Gomez-Roman JJ, Ocejo-Vinyals G, Sanchez-Velasco P, Nieto EH, Leyva-Cobian F, Val-Bernal JF: Presence of human herpesvirus-8 DNA sequences and overexpression of
120 human IL-6 and cyclin D1 in inflammatory myofibroblastic tumor (inflammatory pseudotumor). Lab Invest 80: 1121-1126, 2000 14. Fangusaro J, Klopfenstein K, Groner J, Hammond S, Altura RA: Inflammatory myofibroblastic tumor following hematopoietic stem cell transplantation: Report of two pediatric cases. Bone Marrow Transplant 33:103-107, 2004 15. Remberger K, Weiss M, Gokel JM, Landgraf R, Illner WD, Land W: Inflammatory pseudotumor of the pancreas with persistent hyper-insulinemia and hypoglycemia following long-term pancreatic transplantation. Verh Dtsch Ges Pathol 71:328-332, 1987 16. Lykavieris P, Fabre M, Waguet J, Bernard O: Inflammatory pseudotumor after liver transplantation. J Pediatr Gastroenterol Nutr 31:309-312, 2000
Ma, Zieske, and Fenves 17. Lykavieris P, Fabre M, Pariente D, Lezeau YM, Debray D: Clostridium difficile colitis associated with inflammatory pseudotumor in a liver transplant recipient. Pediatr Transplant 7:76-79, 2003 18. Mizukami H, Yajima N, Wada R, et al: Pancreatic malignant fibrous histiocytoma, inflammatory myofibroblastic tumor and inflammatory pseudotumor related to autoimmune pancreatitis: Characterization and differential diagnosis. Virchows Arch 448:552-560, 2006 19. Esposito I, Bergmann F, Penzel R, et al: Oligoclonal T-cell populations in an inflammatory pseudotumor of the pancreas possibly related to autoimmune pancreatitis: An immunohistochemical and molecular analysis. Virchows Arch 444:119-126, 2004