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Case Report
Open Access Peer-reviewed

Inflammatory Myofibroblastic Pancreas Tumor: A Case Report

Youssef Jakhlal , Fouad Zouaidia, Abdellatif Settaf
Global Journal of Surgery. 2020, 8(2), 24-28. DOI: 10.12691/js-8-2-1
Received June 22, 2020; Revised July 23, 2020; Accepted August 03, 2020

Abstract

Inflammatory myofibroblastic tumor (IMT) is a rare tumor; characterized by a proliferation of myofibroblasts associated with inflammatory reaction cells and which can be observed at the various anatomical sites. The pancreas represents a very rare localization of this tumor. Surgery is the standard treatment, but for inoperable tumors; there is no consensus. We report a case of an inextirpable pancreatic IMT in a 46-years-old woman and we also carry out a literature review.

1. Introduction

The World Health Organization (WHO) has classified inflammatory myofibroblastic tumors (IMT) as low-grade neoplasms composed of myofibroblastic and fibroblastic spindle cells with prominent admixed inflammatory cells, including plasma cells, lymphocytes, and/or eosinophils 1. These lesions have been reported to show clonal proliferation, invasion, recurrence, and distant metastasis 2. IMT primarily affects children and young adults, but it has been reported in adult patients of all ages. IMT was detected in the mesentery, omentum, retroperitoneum, pelvis, and abdominal soft tissue in 73% of cases, followed by the lung, mediastinum, and head and neck 3. Pancreatic location is uncommon and can be confused with malignancy clinically and radiologically and needs to be differentiated from other tumors and chronic pancreatitis.

In this article, we present a new observation of TMI of the pancreas with a literature review.

2. Case Report

A 46-years-old woman operated 3 years ago for a hydatid cyst of the liver, was admitted to hospital with a 3-months history medical of biliary colic type pain without fever or jaundice. All evolving in the context of unencrypted weight loss and apyrexia.

Physical examination shows, in addition to a midline laparotomy scar, a voluminous epigastric mass, with irregular contours, hard and fixed in relation to the deep plane.

The abdominal ultrasound reveals the presence of a 16 cm long cyst formation, adherent to the pancreas with a mass effect on the neighboring organs. The scanner confirms the pancreatic origin of the mass which develops at the expense of the pancreatic body and compresses the neighboring organs with collateral venous circulation. The MRI returned in favor of a partitioned cystic mass of the body of the pancreas evoking in the first place a cystic cystadenoma of the pancreas (Figure 1).

Surgical exploration revealed a mass that could not be extirpated, especially by its adhesions relative to the 4th portion of the duodenum and the superior mesenteric artery, therefore a biopsy was performed. The pathology result returned in favor of a myofibroblastic tumor of the pancreas (Figure 2 and Figure 3) with negative anti-ALK antibodies. The patient received 3 months of corticotherapy without clinical or radiological improvement (MRI) then she was referred to the oncology department.

3. Discussion

Various names have been used to describe IMT, such as plasma cell granuloma, plasma cell pseudotumor, inflammatory pseudotumor, inflammatory fibroxanthoma, and histiocytoma 4. The current WHO classification for this rare tumor entity is a fibroblastic sarcoma or myofibroblastoma, which is a distinctive neoplasm of intermediate biological potential that may be malignant or aggressive 5, 6, 7.

Although IMT has been seen in various organs, it is extremely rare to be seen in the pancreas. We find only 28 cases of histologically confirmed IMTs of pancreas reported in the English language scientific literature. 8 The average age at diagnosis of all cases was 40.0 years, and a subtle predominance of male gender was evident (17 males and 11 females). The pancreatic mass lesions were mostly located in the pancreas head (20 in the head, two in the body, four in the tail, and two in the body and tail) and had an average size of 4.7 cm. 8

Abdominal pain or discomfort was the most frequent symptom (56%, 15/27), with jaundice the second most frequent (44%), followed by anorexia or weight loss (26%), and nausea or vomiting (15%). 8

The radiological features of IMT are nonspecific, and exhibit variable characteristics 9. Ultrasound and CT examinations reveal a solid, or occasionally cystic‑solid, mass in the pancreas, which is usually sized between 5.0 and 10.0 cm and may be well‑demarcated or metastatic 10.

Due to its nonspecific symptoms and imaging findings, definitive diagnosis of IMT relies on histological evaluations 9. EUS-FNA demonstrates a fairly high diagnostic ability (nearly 95% sensitivity and specificity) for solid malignant pancreatic lesions 11, 12. The use of thick core biopsy needles 13 and high-negative-pressure aspiration methods 14 has increased the acquisition rate for obtaining core tissue samples. This, in turn, has enabled the determination of the probable nature of the whole pancreatic mass and even the classification of intermediate inflammatory and neoplastic conditions, such as IMTs 8. The diagnosis of IMT of the pancreas was obtained by EUS-FNA in the only patient in the literature who had this gesture. 8

The biological marker of IMTs, including histological atypia, ganglion-like cells, TP53 expression, and aneuploidy pattern, have been correlated with more aggressive clinical behavior 15. Coffin et al. also suggested that ALK (anaplastic lymphoma kinase) expression is another prognostic indicator of IMTs 16. Approximately half of IMTs carry rearrangements of the anaplastic lymphoma kinase (ALK) gene 16. ALK is a tyrosine kinase receptor that is normally expressed in the central nervous system. Fusion of the ALK gene with partners such as CLTC, RANBP2, TPM3, TPM4, CARS, ATIC, SEC1L1, ALO17, and PPFIBP 17, 18 can cause ALK overexpression and activation of the ALK kinase domain.

The absence of ALK expression in IMT was associated with a higher age of the patients 19. All six of the observed metastases developed in 59 IMTs that were negative for ALK expression, and they developed before 20 years of age (mean age: 13.2 years), indicating a metastatic potential for ALK-negative IMTs in the younger subset 19. Therefore, ALK expression as a clinical indicator in IMTs in older patients needs further evaluation 8.

IMTs show spontaneous regression in a minor fraction of patients. Although the actual incidence is not clear due to surgical procedures and asymptomatic and/or undetected cases, 16 cases of IMT with spontaneous regression, all sites combined, have been reported to date 8, 20, 21 including 2 cases of spontaneous regression reported for the pancreas: the first case of spontaneous regression in 2 months of an IMT of 5cm in an 82-year-old Japanese woman and the second case of regression after 8 weeks of corticosteroid therapy in a 10-year-old child 8, 10. Corticosteroids and/or nonsteroidal anti-inflammatory drugs were used in 5 spontaneous regression patients with extra-pancreatic location 8. Our patient received 3 months of corticotherapy without clinical or radiological improvement.

Surgery with complete excision remains the primary therapeutic option for IMT, although no real consensus regarding the treatment of IMT exists 10, 22. The low risk of malignant transformation or metastasis has been described in previous cases of IMT, but if the excision is incomplete, the risk increases from <5 to 25% 5. Due to the possibility of malignancy and relapse, many authors have reported that a simple tumor excision is uncertain 23 and that radical resection may be appropriate if the patient's physical condition is adequate 10, 22.

For unresectable, metastatic or recurrent lesions, several medical treatments, including chemotherapy, radiotherapy, nonsteroidal anti-inflammatory drugs, corticosteroids, antitumor necrosis factor‑binding antibodies and ALK inhibitors, have been previously administered to palliate or shrink these IMTs to a resectable size and configuration 9, 10, 23. Ogata has grouped 7 cases from the literature for which crizotinib, an ALK inhibitor, has been used for tumors harboring ALK mutations. The patients were young and the locations of the tumors were varied. In the majority of cases, crizotinib initially provided a partial or very good response; but the end result was different 24. A dramatic response to alectinib in inflammatory myofibroblastic tumor with ALK fusion gene with renal metastasis has also been reported 25.

According to a retrospective analysis of the value of chemotherapy in the treatment of IMT, in 38 patients under the age of 21, all locations combined, chemotherapy with alkylator-based regimens seems to be justified to attempt to reduce tumor size in unresectable cases to enable tumor resection 26. The combination of methotrexate and vinorelbine allowed a partial response to a recurrence of an inoperable IMT of the gallbladder in a 62-year-old patient 27.

Rituximab, an anti-CD20 antibody, was used in 2 cases of IMT; one of the mandible and the other of the central nervous system. A long-term response has been obtained 28.

Recently, a clinical study showed a high degree of PD-1/PDL-1 expression in the TMIs 29. This could imply immune-mediated dysfunction in the development of IMT 19, 30, 31. On the other hand, the expression of PD-1/PD-L1 could predict the effectiveness of immunotherapy in the future. the PD-L1 status appears to be independent of ALK status, suggesting that it could be particularly useful clinically in ALK-negative IMT or those resistant to tyrosine kinase inhibitor therapy. 29

4. Conclusion

For unresectable, metastatic or recurrent IMD lesions, medical treatment remains poorly defined given the lack of strong statistical evidence. The choice between chemotherapy, ALK inhibitors and immunotherapy is difficult and requires further study of predictive factors for a therapeutic response like ALK expression and PD1/PD-L1 expression. We also point out the need for the use of TNM classification and objective therapeutic response criteria in future studies.

References

[1]  Coffin CM, Fletcher JA. Inflammatory myofibroblastic tumor. In: Fletcher CDM, Unni KK, editors. World Health Organization classification of tumours. Pathology and genetics of tumours of soft tissue and bone. Lyon : IARC Press; 2002. p. 91-3.
In article      
 
[2]  Sastre-Garau X, Couturier J, Derré J, et al. Inflammatory myofibroblastic tumour (inflammatory pseudotumour) of the breast. Clinicopathological and genetic analysis of a case with evidence for clonality. J Pathol. 2002; 196:97-102.
In article      View Article  PubMed
 
[3]  World Health Organization. World Health Organization classification of tumours of the breast. 4th ed. Lyon: IARC Press; 2012. p. 133.
In article      
 
[4]  Yamamoto, H., K. Watanabe, M. Nagata, K. Tasaki, I. Honda, and S. Watanabe. 2002. Inflammatory myofibroblastic tumor (IMT) of the pancreas. J. Hepatobiliary Pancreat. Surg. 9:116-119.
In article      View Article  PubMed
 
[5]  Fletcher CDM, Bridge JA, Hogendoorn P and Mertens F (eds): World Health Organization Classification of Tumours of Soft Tissue and Bone. In: World Health Organization Classification of Tumors. Vol 5. 4th edition. IARC Press, Lyon, 2013.
In article      
 
[6]  Fragoso AC, Eloy C, Estevão‑Costa J, Campos M, Farinha N and Lopes JM: Abdominal inflammatory myofibroblastic tumor a clinicopathologic study with reappraisal of biologic behavior. J Pediatr Surg 46: 2076‑2082, 2011.
In article      View Article  PubMed
 
[7]  Coindre JM: New WHO classification of tumours of soft tissue and bone. Ann Pathol 32 (Suppl 5): S115‑S116, 2012 (In French).
In article      View Article  PubMed
 
[8]  Hiroyuki Matsubayashi, Katsuhiko Uesaka, Keiko Sasaki, Seitaro Shimada and al: A Pancreatic Inflammatory Myofibroblastic Tumor with Spontaneous Remission: A Case Report with a Literature Review. Diagnostics 2019, 9, 150.
In article      View Article  PubMed
 
[9]  Sim A, Lee MW and Nguyen GK: Inflammatory myofibroblastic tumour of the pancreas. Can J Surg 51, E23-E24, 2008.
In article      
 
[10]  Dagash H, Koh C, Cohen M, Sprigg A and Walker J: Inflammatory myofibroblastic tumor of the pancreas: A case report of 2 pediatric cases ‑ steroids or surgery? J Pediatr Surg 44: 1839-1841, 2009.
In article      View Article  PubMed
 
[11]  Matsubayashi, H.; Matsui, T.; Yabuuchi, Y.; Imai, K.; Tanaka, M.; Kakushima, N.; Sasaki, K.; Ono, H. Endoscopic ultrasonography guided-fine needle aspiration for the diagnosis of solid pancreaticobiliary lesions: Clinical aspects to improve the diagnosis. World J. Gastroenterol. 2016, 22, 628-640.
In article      View Article  PubMed
 
[12]  Ishiwatari, H.; Sato, J.; Fujie, S.; Sasaki, K.; Kaneko, J.; Satoh, T.; Matsubayashi, H.; Kishida, Y.; Yoshida, M.; Ito, S.; et al. Gross visual inspection by endosonographers during endoscopic ultrasound-guided fine needle aspiration. Pancreatology 2019, 19, 191-195.
In article      View Article  PubMed
 
[13]  Fujie, S.; Ishiwatari, H.; Sasaki, K.; Sato, J.; Matsubayashi, H.; Yoshida, M.; Ito, S.; Kawata, N.; Imai, K.; Kakushima, N.; et al. Comparison of the Diagnostic Yield of the Standard 22-Gauge Needle and the New 20-Gauge Forward-Bevel Core Biopsy Needle for Endoscopic Ultrasound-Guided Tissue Acquisition from Pancreatic Lesions. Gut Liver 2019, 13, 349-355.
In article      View Article  PubMed
 
[14]  Sato, J.; Ishiwatari, H.; Sasaki, K.; Fujie, S.; Kaneko, J.; Satoh, T.; Matsubayashi, H.; Kishida, Y.; Yoshida, M.; Ito, S.; et al. Benefit of high negative pressure during endoscopic ultrasound-guided fine-needle aspiration with standard 22-gauge needles for pancreatic lesions: A retrospective comparative study. Scand. J. Gastroenterol. 2019, 54, 108-113.
In article      View Article  PubMed
 
[15]  Hussong, J.W.; Brown, M.; Perkins, S.L.; Dehner, L.P.; Con, C.M. Comparison of DNA ploidy, histologic, and immunohistochemical findings with clinical outcome in inflammatory myofibroblastic tumors. Mod. Pathol. 1999, 12, 279-286.
In article      
 
[16]  Coffin CM, Patel A, Perkins S, Elenitoba-Johnson KS, Perlman E, Griffin CA. ALK1 and p80 expression and chromosomal rearrangements involving 2p23 in inflammatory myofibroblastic tumor. Mod Pathol 2001; 14:569-576.
In article      View Article  PubMed
 
[17]  Takeuchi K, Soda M, Togashi Y, Sugawara E, Hatano S, Asaka R, Okumura S, Nakagawa K, Mano H, Ishikawa Y. Pulmonary inflammatory myofibroblastic tumor expressing a novel fusion, PPFIBP1-ALK: Reappraisal of anti-ALK immunohistochemistry as a tool for novel ALK fusion identification. Clin Cancer Rese 2011; 17: 3341-3348.
In article      View Article  PubMed
 
[18]  Cools J, Wlodarska I, Somers R, Mentens N, Pedeutour F, Maes B, De Wolf-Peeters C, Pauwels P, Hagemeijer A, Marynen P. Identification of novel fusion partners of ALK, the anaplastic lymphoma kinase, in anaplastic large-cell lymphoma and inflammatory myofibroblastic tumor. Genes Chromosomes Cancer 2002; 34: 354-362.
In article      View Article  PubMed
 
[19]  Coffin, C.M.; Hornick, J.L.; Fletcher, C.D. Inflammatory myofibroblastic tumor: Comparison of clinicopathologic, histologic, and immunohistochemical features including ALK expression in atypical and aggressive cases. Am. J. Surg. Pathol. 2007, 31, 509-520.
In article      View Article  PubMed
 
[20]  Przkora, R.; Bolder, U.; Schwarz, S.; Jauch, K.W.; Spes, J.; Andreesen, R.; Mackensen, A. Regression of nonresectable inflammatory myofibroblastic tumours after treatment with nonsteroidal anti-inflammatory drugs. Eur. J. Clin. Investig. 2004, 34, 320-321.
In article      View Article  PubMed
 
[21]  Habib, L.; Son, J.H.; Petris, C.; Kazim, M. Spontaneous regression of inflammatory myofibroblastic tumor of the orbit: A case report and review of literature. Orbit 2017, 36, 178-182.
In article      View Article  PubMed
 
[22]  Tomazic A, Gvardijancic D, Maucec J and Homan M: Inflammatory myofibroblastic tumor of the pancreatic head ‑ a case report of a 6 months old child and review of the literature. Radiol Oncol 49: 265-270, 2015.
In article      View Article  PubMed
 
[23]  Pungpapong S, Geiger XJ and Raimondo M: Inflam matory myofibroblastic tumor presenting as a pancreatic mass: A case report and review of the literature. JOP 5: 360-367, 2004.
In article      
 
[24]  Misato Ogata, Yukimasa Hatachi, Takatsugu Ogata, Hironaga Satake: Effectiveness of Crizotinib for Inflammatory Myofibroblastic Tumor with ALK mutation: A Case Report. Intern Med Advance Publication.
In article      
 
[25]  Masafumi Saiki, Fumiyoshi Ohyanagi, Ryo Ariyasu, Junji Koyama and al: Dramatic response to alectinib in inflammatory myofibroblastic tumor with anaplastic lymphoma kinase fusion gene. Japanese Journal of Clinical Oncology, 2017, 47(12). 1189-1192.
In article      View Article  PubMed
 
[26]  Kube S, Vokuhl C, Dantonello T, et al. Inflammatory myofibroblastic tumors-a retrospective analysis of the Cooperative Weichteilsarkom Studiengruppe. Pediatr Blood Cancer. 2018; e27012.
In article      View Article  PubMed
 
[27]  Maruyama et al: Chemotherapy for inflammatory myofibroblastic tumor. Molecular and clinical oncology. 7: 521-524, 2017.
In article      View Article  PubMed
 
[28]  Ameet Patel, Mehmet H. Kocoglu, Akash Kaul: Therapeutic strategies for durable response in plasma cell granulomas in the central nervous system. Annals of Hematology.
In article      
 
[29]  Cottrell TR, Duong AT, Gocke CD, Xu H, Ogurtsova A, Taube JM, Belchis DA (2018) PD-L1 expression in inflammatory myofibroblastic tumors. Mod Pathol 31:1155-1163.
In article      View Article  PubMed
 
[30]  Gleason BC, Hornick JL (2008) Inflammatory myofibroblastic tumours: where are we now? J Clin Pathol 61(4): 428-437.
In article      View Article  PubMed
 
[31]  Garcia BA, Tinsley S, Schellenberger T, Bobustuc GC (2012) Recurrent inflammatory pseudotumor of the jaw with perineural intracranial invasion demonstrating sustained response to Rituximab. Med Oncol 29(4): 2452-2455.
In article      View Article  PubMed
 

Published with license by Science and Education Publishing, Copyright © 2020 Youssef Jakhlal, Fouad Zouaidia and Abdellatif Settaf

Creative CommonsThis work is licensed under a Creative Commons Attribution 4.0 International License. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/

Cite this article:

Normal Style
Youssef Jakhlal, Fouad Zouaidia, Abdellatif Settaf. Inflammatory Myofibroblastic Pancreas Tumor: A Case Report. Global Journal of Surgery. Vol. 8, No. 2, 2020, pp 24-28. http://pubs.sciepub.com/js/8/2/1
MLA Style
Jakhlal, Youssef, Fouad Zouaidia, and Abdellatif Settaf. "Inflammatory Myofibroblastic Pancreas Tumor: A Case Report." Global Journal of Surgery 8.2 (2020): 24-28.
APA Style
Jakhlal, Y. , Zouaidia, F. , & Settaf, A. (2020). Inflammatory Myofibroblastic Pancreas Tumor: A Case Report. Global Journal of Surgery, 8(2), 24-28.
Chicago Style
Jakhlal, Youssef, Fouad Zouaidia, and Abdellatif Settaf. "Inflammatory Myofibroblastic Pancreas Tumor: A Case Report." Global Journal of Surgery 8, no. 2 (2020): 24-28.
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  • Figure 1. MRI showing a partitioned cystic mass of the body of the pancreas. A: T1-weighted fat-saturated post-gadolinium image, B: T2-weighted fat-saturated image
  • Figure 3. Myofibroblastic cells staining positive for smooth muscle actin. Smooth muscle of blood vessels acted as an internal positive control. (Gx200 HE)
[1]  Coffin CM, Fletcher JA. Inflammatory myofibroblastic tumor. In: Fletcher CDM, Unni KK, editors. World Health Organization classification of tumours. Pathology and genetics of tumours of soft tissue and bone. Lyon : IARC Press; 2002. p. 91-3.
In article      
 
[2]  Sastre-Garau X, Couturier J, Derré J, et al. Inflammatory myofibroblastic tumour (inflammatory pseudotumour) of the breast. Clinicopathological and genetic analysis of a case with evidence for clonality. J Pathol. 2002; 196:97-102.
In article      View Article  PubMed
 
[3]  World Health Organization. World Health Organization classification of tumours of the breast. 4th ed. Lyon: IARC Press; 2012. p. 133.
In article      
 
[4]  Yamamoto, H., K. Watanabe, M. Nagata, K. Tasaki, I. Honda, and S. Watanabe. 2002. Inflammatory myofibroblastic tumor (IMT) of the pancreas. J. Hepatobiliary Pancreat. Surg. 9:116-119.
In article      View Article  PubMed
 
[5]  Fletcher CDM, Bridge JA, Hogendoorn P and Mertens F (eds): World Health Organization Classification of Tumours of Soft Tissue and Bone. In: World Health Organization Classification of Tumors. Vol 5. 4th edition. IARC Press, Lyon, 2013.
In article      
 
[6]  Fragoso AC, Eloy C, Estevão‑Costa J, Campos M, Farinha N and Lopes JM: Abdominal inflammatory myofibroblastic tumor a clinicopathologic study with reappraisal of biologic behavior. J Pediatr Surg 46: 2076‑2082, 2011.
In article      View Article  PubMed
 
[7]  Coindre JM: New WHO classification of tumours of soft tissue and bone. Ann Pathol 32 (Suppl 5): S115‑S116, 2012 (In French).
In article      View Article  PubMed
 
[8]  Hiroyuki Matsubayashi, Katsuhiko Uesaka, Keiko Sasaki, Seitaro Shimada and al: A Pancreatic Inflammatory Myofibroblastic Tumor with Spontaneous Remission: A Case Report with a Literature Review. Diagnostics 2019, 9, 150.
In article      View Article  PubMed
 
[9]  Sim A, Lee MW and Nguyen GK: Inflammatory myofibroblastic tumour of the pancreas. Can J Surg 51, E23-E24, 2008.
In article      
 
[10]  Dagash H, Koh C, Cohen M, Sprigg A and Walker J: Inflammatory myofibroblastic tumor of the pancreas: A case report of 2 pediatric cases ‑ steroids or surgery? J Pediatr Surg 44: 1839-1841, 2009.
In article      View Article  PubMed
 
[11]  Matsubayashi, H.; Matsui, T.; Yabuuchi, Y.; Imai, K.; Tanaka, M.; Kakushima, N.; Sasaki, K.; Ono, H. Endoscopic ultrasonography guided-fine needle aspiration for the diagnosis of solid pancreaticobiliary lesions: Clinical aspects to improve the diagnosis. World J. Gastroenterol. 2016, 22, 628-640.
In article      View Article  PubMed
 
[12]  Ishiwatari, H.; Sato, J.; Fujie, S.; Sasaki, K.; Kaneko, J.; Satoh, T.; Matsubayashi, H.; Kishida, Y.; Yoshida, M.; Ito, S.; et al. Gross visual inspection by endosonographers during endoscopic ultrasound-guided fine needle aspiration. Pancreatology 2019, 19, 191-195.
In article      View Article  PubMed
 
[13]  Fujie, S.; Ishiwatari, H.; Sasaki, K.; Sato, J.; Matsubayashi, H.; Yoshida, M.; Ito, S.; Kawata, N.; Imai, K.; Kakushima, N.; et al. Comparison of the Diagnostic Yield of the Standard 22-Gauge Needle and the New 20-Gauge Forward-Bevel Core Biopsy Needle for Endoscopic Ultrasound-Guided Tissue Acquisition from Pancreatic Lesions. Gut Liver 2019, 13, 349-355.
In article      View Article  PubMed
 
[14]  Sato, J.; Ishiwatari, H.; Sasaki, K.; Fujie, S.; Kaneko, J.; Satoh, T.; Matsubayashi, H.; Kishida, Y.; Yoshida, M.; Ito, S.; et al. Benefit of high negative pressure during endoscopic ultrasound-guided fine-needle aspiration with standard 22-gauge needles for pancreatic lesions: A retrospective comparative study. Scand. J. Gastroenterol. 2019, 54, 108-113.
In article      View Article  PubMed
 
[15]  Hussong, J.W.; Brown, M.; Perkins, S.L.; Dehner, L.P.; Con, C.M. Comparison of DNA ploidy, histologic, and immunohistochemical findings with clinical outcome in inflammatory myofibroblastic tumors. Mod. Pathol. 1999, 12, 279-286.
In article      
 
[16]  Coffin CM, Patel A, Perkins S, Elenitoba-Johnson KS, Perlman E, Griffin CA. ALK1 and p80 expression and chromosomal rearrangements involving 2p23 in inflammatory myofibroblastic tumor. Mod Pathol 2001; 14:569-576.
In article      View Article  PubMed
 
[17]  Takeuchi K, Soda M, Togashi Y, Sugawara E, Hatano S, Asaka R, Okumura S, Nakagawa K, Mano H, Ishikawa Y. Pulmonary inflammatory myofibroblastic tumor expressing a novel fusion, PPFIBP1-ALK: Reappraisal of anti-ALK immunohistochemistry as a tool for novel ALK fusion identification. Clin Cancer Rese 2011; 17: 3341-3348.
In article      View Article  PubMed
 
[18]  Cools J, Wlodarska I, Somers R, Mentens N, Pedeutour F, Maes B, De Wolf-Peeters C, Pauwels P, Hagemeijer A, Marynen P. Identification of novel fusion partners of ALK, the anaplastic lymphoma kinase, in anaplastic large-cell lymphoma and inflammatory myofibroblastic tumor. Genes Chromosomes Cancer 2002; 34: 354-362.
In article      View Article  PubMed
 
[19]  Coffin, C.M.; Hornick, J.L.; Fletcher, C.D. Inflammatory myofibroblastic tumor: Comparison of clinicopathologic, histologic, and immunohistochemical features including ALK expression in atypical and aggressive cases. Am. J. Surg. Pathol. 2007, 31, 509-520.
In article      View Article  PubMed
 
[20]  Przkora, R.; Bolder, U.; Schwarz, S.; Jauch, K.W.; Spes, J.; Andreesen, R.; Mackensen, A. Regression of nonresectable inflammatory myofibroblastic tumours after treatment with nonsteroidal anti-inflammatory drugs. Eur. J. Clin. Investig. 2004, 34, 320-321.
In article      View Article  PubMed
 
[21]  Habib, L.; Son, J.H.; Petris, C.; Kazim, M. Spontaneous regression of inflammatory myofibroblastic tumor of the orbit: A case report and review of literature. Orbit 2017, 36, 178-182.
In article      View Article  PubMed
 
[22]  Tomazic A, Gvardijancic D, Maucec J and Homan M: Inflammatory myofibroblastic tumor of the pancreatic head ‑ a case report of a 6 months old child and review of the literature. Radiol Oncol 49: 265-270, 2015.
In article      View Article  PubMed
 
[23]  Pungpapong S, Geiger XJ and Raimondo M: Inflam matory myofibroblastic tumor presenting as a pancreatic mass: A case report and review of the literature. JOP 5: 360-367, 2004.
In article      
 
[24]  Misato Ogata, Yukimasa Hatachi, Takatsugu Ogata, Hironaga Satake: Effectiveness of Crizotinib for Inflammatory Myofibroblastic Tumor with ALK mutation: A Case Report. Intern Med Advance Publication.
In article      
 
[25]  Masafumi Saiki, Fumiyoshi Ohyanagi, Ryo Ariyasu, Junji Koyama and al: Dramatic response to alectinib in inflammatory myofibroblastic tumor with anaplastic lymphoma kinase fusion gene. Japanese Journal of Clinical Oncology, 2017, 47(12). 1189-1192.
In article      View Article  PubMed
 
[26]  Kube S, Vokuhl C, Dantonello T, et al. Inflammatory myofibroblastic tumors-a retrospective analysis of the Cooperative Weichteilsarkom Studiengruppe. Pediatr Blood Cancer. 2018; e27012.
In article      View Article  PubMed
 
[27]  Maruyama et al: Chemotherapy for inflammatory myofibroblastic tumor. Molecular and clinical oncology. 7: 521-524, 2017.
In article      View Article  PubMed
 
[28]  Ameet Patel, Mehmet H. Kocoglu, Akash Kaul: Therapeutic strategies for durable response in plasma cell granulomas in the central nervous system. Annals of Hematology.
In article      
 
[29]  Cottrell TR, Duong AT, Gocke CD, Xu H, Ogurtsova A, Taube JM, Belchis DA (2018) PD-L1 expression in inflammatory myofibroblastic tumors. Mod Pathol 31:1155-1163.
In article      View Article  PubMed
 
[30]  Gleason BC, Hornick JL (2008) Inflammatory myofibroblastic tumours: where are we now? J Clin Pathol 61(4): 428-437.
In article      View Article  PubMed
 
[31]  Garcia BA, Tinsley S, Schellenberger T, Bobustuc GC (2012) Recurrent inflammatory pseudotumor of the jaw with perineural intracranial invasion demonstrating sustained response to Rituximab. Med Oncol 29(4): 2452-2455.
In article      View Article  PubMed