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Inflammatory myofibroblastic tumor (plasma cell granuloma) of the lung

Steven E Weinberger, MD
Section Editor
Kevin R Flaherty, MD, MS
Deputy Editor
Helen Hollingsworth, MD


Inflammatory myofibroblastic tumor (IMT) of the lung (also known as plasma cell granuloma, inflammatory pseudotumor, fibrous histiocytoma, fibroxanthoma, and xanthogranuloma) includes a spectrum of pulmonary lesions. Such lesions most commonly present as solitary pulmonary nodules, but can also be locally invasive [1-4]. It is currently unclear whether these lesions represent a primary inflammatory process versus a low-grade malignancy with a prominent inflammatory response.

Similar lesions, referred to variably in the literature as plasma cell granulomas or inflammatory pseudotumors, can also develop in the orbit, skull base, thyroid, liver, spine, spleen, lymph nodes, and other tissues [1-3,5-9]. (See "Evaluation of peripheral lymphadenopathy in adults".)


IMTs can occur in any age group, but over half of the patients are less than 40 years of age [10,11]. Although IMTs are rare, comprising less than 1 percent of all surgically resected lung lesions, they do represent one of the most common primary lung tumors in the pediatric age group [4,12-17]. Both sexes and all ethnic groups appear to be equally affected.


There is significant controversy and confusion regarding the pathogenesis and histogenesis of these uncommon tumors or tumor-like masses (picture 1). Much of the confusion has been caused by the varying degrees of inflammatory cell infiltration noted on pathologic examination and the observation that the disease process, although usually following a benign course, is sometimes invasive. As a result, a variety of terms have been used to describe lesions falling under the category of IMT.

The early terminology "pulmonary plasma cell/histiocytoma complex" emphasized the histologic heterogeneity and a belief in the benign nature of the lesions [18]. Subsequently, plasma cell granuloma was the common terminology for lung lesions, acknowledging the circumscribed appearance, presence of plasma cells and histiocytes, and generally benign course. The term inflammatory pseudotumor was typically used to describe extrapulmonary lesions with similar pathology [19-21]. More malignant variants were felt to be analogous to undifferentiated "pleomorphic" sarcomas (previously termed malignant fibrous histiocytoma) arising in soft tissues. (See "Clinical presentation, histopathology, diagnostic evaluation, and staging of soft tissue sarcoma", section on 'Histopathology'.)

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Literature review current through: Nov 2017. | This topic last updated: Jul 15, 2016.
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  1. Mahr MA, Salomao DR, Garrity JA. Inflammatory orbital pseudotumor with extension beyond the orbit. Am J Ophthalmol 2004; 138:396.
  2. Buccoliero AM, Caldarella A, Santucci M, et al. Plasma cell granuloma--an enigmatic lesion: description of an extensive intracranial case and review of the literature. Arch Pathol Lab Med 2003; 127:e220.
  3. Martinez F, Filipowicz E, Hudnall SD. Plasma cell granuloma of the thyroid. Arch Pathol Lab Med 2002; 126:595.
  4. Nonomura A, Mizukami Y, Matsubara F, et al. Seven patients with plasma cell granuloma (inflammatory pseudotumor) of the lung, including two with intrabronchial growth: an immunohistochemical and electron microscopic study. Intern Med 1992; 31:756.
  5. Koea JB, Broadhurst GW, Rodgers MS, McCall JL. Inflammatory pseudotumor of the liver: demographics, diagnosis, and the case for nonoperative management. J Am Coll Surg 2003; 196:226.
  6. Aizawa T, Sato T, Tanaka Y, et al. Intramedullary plasma cell granuloma in the cervicothoracic spine. Case report. J Neurosurg 2002; 97:235.
  7. Lewis JT, Gaffney RL, Casey MB, et al. Inflammatory pseudotumor of the spleen associated with a clonal Epstein-Barr virus genome. Case report and review of the literature. Am J Clin Pathol 2003; 120:56.
  8. Lee SH, Fang YC, Luo JP, et al. Inflammatory pseudotumour associated with chronic persistent Eikenella corrodens infection: a case report and brief review. J Clin Pathol 2003; 56:868.
  9. Ceruse P, Ramade A, Vautrin R, et al. Inflammatory pseudotumor of the neck: a long-term result without surgical approach. Otolaryngol Head Neck Surg 2005; 132:812.
  10. Kim JH, Cho JH, Park MS, et al. Pulmonary inflammatory pseudotumor--a report of 28 cases. Korean J Intern Med 2002; 17:252.
  11. Lai LM, McCarville MB, Kirby P, et al. Shedding light on inflammatory pseudotumor in children: spotlight on inflammatory myofibroblastic tumor. Pediatr Radiol 2015; 45:1738.
  12. Vancauwenbergh A, Smet MH, Breysem L. Inflammatory pseudotumor of the lung. JBR-BTR 2002; 85:209.
  13. Urschel JD, Horan TA, Unruh HW. Plasma cell granuloma of the lung. J Thorac Cardiovasc Surg 1992; 104:870.
  14. Ishida T, Oka T, Nishino T, et al. Inflammatory pseudotumor of the lung in adults: radiographic and clinicopathological analysis. Ann Thorac Surg 1989; 48:90.
  15. Lebecque P, Lapierre JG, Brochu P, et al. Pulmonary plasma cell granuloma. Eur J Pediatr 1987; 146:174.
  16. Pettinato G, Manivel JC, De Rosa N, Dehner LP. Inflammatory myofibroblastic tumor (plasma cell granuloma). Clinicopathologic study of 20 cases with immunohistochemical and ultrastructural observations. Am J Clin Pathol 1990; 94:538.
  17. Souid AK, Ziemba MC, Dubansky AS, et al. Inflammatory myofibroblastic tumor in children. Cancer 1993; 72:2042.
  18. Spencer H. The pulmonary plasma cell/histiocytoma complex. Histopathology 1984; 8:903.
  19. Melloni G, Carretta A, Ciriaco P, et al. Inflammatory pseudotumor of the lung in adults. Ann Thorac Surg 2005; 79:426.
  20. Sakurai H, Hasegawa T, Watanabe Si, et al. Inflammatory myofibroblastic tumor of the lung. Eur J Cardiothorac Surg 2004; 25:155.
  21. World Health Organization Classification of Tumors. Pathology and Genetics of the Lung, Pleura, Thymus, and Heart, Travis, WD, Brambilla, E, Muller-Hermelink, HK, et al (Eds), IARC Press, Lyon 2004.
  22. Warter A, Satge D, Roeslin N. Angioinvasive plasma cell granulomas of the lung. Cancer 1987; 59:435.
  23. Berardi RS, Lee SS, Chen HP, Stines GJ. Inflammatory pseudotumors of the lung. Surg Gynecol Obstet 1983; 156:89.
  24. Matsubara O, Tan-Liu NS, Kenney RM, Mark EJ. Inflammatory pseudotumors of the lung: progression from organizing pneumonia to fibrous histiocytoma or to plasma cell granuloma in 32 cases. Hum Pathol 1988; 19:807.
  25. Gómez-Román JJ, Sánchez-Velasco P, Ocejo-Vinyals G, et al. Human herpesvirus-8 genes are expressed in pulmonary inflammatory myofibroblastic tumor (inflammatory pseudotumor). Am J Surg Pathol 2001; 25:624.
  26. Gómez-Román JJ, Ocejo-Vinyals G, Sánchez-Velasco P, et al. Presence of human herpesvirus-8 DNA sequences and overexpression of human IL-6 and cyclin D1 in inflammatory myofibroblastic tumor (inflammatory pseudotumor). Lab Invest 2000; 80:1121.
  27. Tavora F, Shilo K, Ozbudak IH, et al. Absence of human herpesvirus-8 in pulmonary inflammatory myofibroblastic tumor: immunohistochemical and molecular analysis of 20 cases. Mod Pathol 2007; 20:995.
  28. Rohrlich P, Peuchmaur M, Cocci SN, et al. Interleukin-6 and interleukin-1 beta production in a pediatric plasma cell granuloma of the lung. Am J Surg Pathol 1995; 19:590.
  29. Gal AA, Koss MN, McCarthy WF, Hochholzer L. Prognostic factors in pulmonary fibrohistiocytic lesions. Cancer 1994; 73:1817.
  30. Kovach SJ, Fischer AC, Katzman PJ, et al. Inflammatory myofibroblastic tumors. J Surg Oncol 2006; 94:385.
  31. Lawrence B, Perez-Atayde A, Hibbard MK, et al. TPM3-ALK and TPM4-ALK oncogenes in inflammatory myofibroblastic tumors. Am J Pathol 2000; 157:377.
  32. Butrynski JE, D'Adamo DR, Hornick JL, et al. Crizotinib in ALK-rearranged inflammatory myofibroblastic tumor. N Engl J Med 2010; 363:1727.
  33. Coffin CM, Patel A, Perkins S, et al. ALK1 and p80 expression and chromosomal rearrangements involving 2p23 in inflammatory myofibroblastic tumor. Mod Pathol 2001; 14:569.
  34. Narla LD, Newman B, Spottswood SS, et al. Inflammatory pseudotumor. Radiographics 2003; 23:719.
  35. Kato S, Kondo K, Teramoto T, et al. A case report of inflammatory pseudotumor of the lung: rapid recurrence appearing as multiple lung nodules. Ann Thorac Cardiovasc Surg 2002; 8:224.
  36. van den Heuvel DA, Keijsers RG, van Es HW, et al. Invasive inflammatory myofibroblastic tumor of the lung. J Thorac Oncol 2009; 4:923.
  37. Dua SG, Purandare N, Pramesh CS, et al. Fluoro-deoxy glucose-avid endobronchial inflammatory myofibroblastic tumor mimicking bronchial malignancy: report of a case. J Cancer Res Ther 2011; 7:340.
  38. Dong A, Wang Y, Dong H, et al. Inflammatory myofibroblastic tumor: FDG PET/CT findings with pathologic correlation. Clin Nucl Med 2014; 39:113.
  39. Kushihashi T, Munechika H, Satou S, et al. [CT findings of pulmonary inflammatory pseudotumors (plasma cell granulomas)]. Nihon Igaku Hoshasen Gakkai Zasshi 1994; 54:13.
  40. Oteo Domínguez JF, Yebra Bango M, Varela de Ugarte A, et al. [Endobronchial inflammatory pseudotumor. A case report and review of the literature]. Arch Bronconeumol 1994; 30:52.
  41. Thistlethwaite PA, Renner J, Duhamel D, et al. Surgical management of endobronchial inflammatory myofibroblastic tumors. Ann Thorac Surg 2011; 91:367.
  42. Bando T, Fujimura M, Noda Y, et al. Pulmonary plasma cell granuloma improves with corticosteroid therapy. Chest 1994; 105:1574.
  43. Barbareschi M, Ferrero S, Aldovini D, et al. Inflammatory pseudotumour of the lung. Immunohistochemical analysis on four new cases. Histol Histopathol 1990; 5:205.
  44. Daudi FA, Lees GM, Higa TE. Inflammatory pseudotumours of the lung: two cases and a review. Can J Surg 1991; 34:461.
  45. Dahabreh J, Zisis C, Arnogiannaki N, Katis K. Inflammatory pseudotumor: a controversial entity. Eur J Cardiothorac Surg 1999; 16:670.
  46. Cerfolio RJ, Matthews TC. Resection of the entire left mainstem bronchus for an inflammatory pseudotumor. Ann Thorac Surg 2005; 79:2127.
  47. Fabre D, Fadel E, Singhal S, et al. Complete resection of pulmonary inflammatory pseudotumors has excellent long-term prognosis. J Thorac Cardiovasc Surg 2009; 137:435.
  48. Mandelbaum I, Brashear RE, Hull MT. Surgical treatment and course of pulmonary pseudotumor (plasma cell granuloma). J Thorac Cardiovasc Surg 1981; 82:77.
  49. Venuta F, Rendina EA, Pompeo E, et al. Regression of autoimmune thrombocythemia after resection of pulmonary plasma cell granuloma. J Thorac Cardiovasc Surg 1994; 108:393.
  50. Christensen JG, Zou HY, Arango ME, et al. Cytoreductive antitumor activity of PF-2341066, a novel inhibitor of anaplastic lymphoma kinase and c-Met, in experimental models of anaplastic large-cell lymphoma. Mol Cancer Ther 2007; 6:3314.
  51. Zou HY, Li Q, Lee JH, et al. An orally available small-molecule inhibitor of c-Met, PF-2341066, exhibits cytoreductive antitumor efficacy through antiproliferative and antiangiogenic mechanisms. Cancer Res 2007; 67:4408.
  52. Mossé YP, Lim MS, Voss SD, et al. Safety and activity of crizotinib for paediatric patients with refractory solid tumours or anaplastic large-cell lymphoma: a Children's Oncology Group phase 1 consortium study. Lancet Oncol 2013; 14:472.
  53. Chen CH, Huang WC, Liu HC, et al. Surgical outcome of inflammatory pseudotumor in the lung. Thorac Cardiovasc Surg 2008; 56:214.
  54. Berman M, Georghiou GP, Schonfeld T, et al. Pulmonary inflammatory myofibroblastic tumor invading the left atrium. Ann Thorac Surg 2003; 76:601.
  55. Corneli G, Alifano M, Forti Parri S, et al. Invasive inflammatory pseudo-tumor involving the lung and the mediastinum. Thorac Cardiovasc Surg 2001; 49:124.
  56. Weinberg PB, Bromberg PA, Askin FB. "Recurrence" of a plasma cell granuloma 11 years after initial resection. South Med J 1987; 80:519.
  57. Cerfolio RJ, Allen MS, Nascimento AG, et al. Inflammatory pseudotumors of the lung. Ann Thorac Surg 1999; 67:933.