Oral inflammatory myofibroblastic tumor demonstrating ALK, p53, MDM2, CDK4, pRb, and Ki-67 immunoreactivity in an elderly patient

Nodular fasciitis arising from the buccal region after segmentectomy with rapid growth mimicking postirradiation myxofibrosarcoma: A case report

RATIONALE

Nodular fasciitis (NF) can be misdiagnosed as a sarcoma because of its rapid growth and pathological features, such as nuclear atypia and mitoses.

PATIENT CONCERNS

We present a rare case of a 72-year-old Japanese man who developed NF with suspected postirradiation myxofibrosarcoma (MFS) after segmentectomy for left-sided osteoradionecrosis (ORN) of the mandible.

DIAGNOSIS

A mass appeared in the intraoral postoperative wound 1 year after left-sided mandibular segmentectomy and showed rapid growth, reaching a size of 50 mm within 2 months. Incisional biopsy revealed strongly Ki-67-positive spindle-shaped cells with large irregular nuclei and a diagnosis of postirradiation MFS.

INTERVENTIONS

The patient was diagnosed with oropharyngeal cancer (T4aN2bM0) and underwent surgical resection of primary oropharyngeal squamous cell carcinoma with selective neck dissection and reconstruction with a rectus abdominis musculocutaneous flap at the age of 57 years, followed by postoperative 66 Gy of radiotherapy combined with cisplatin administration. No recurrent or metastatic lesions of oropharyngeal squamous cell carcinoma have been detected for > 10 years. However, the ORN of the jaw worsened, and the patient underwent sequestrectomy 3 times on the right side of the mandible, followed by a left-sided segmentectomy at the age of 72 years. One year after segmentectomy, a 10-mm mass with soft-to-firm consistency appeared in the buccal mucosa of the wound and grew rapidly. An incisional biopsy revealed MFS. Complete resection under general anesthesia was immediately performed.

OUTCOMES

The histopathological diagnosis of the excised specimen was NF without any malignant findings. Two years after surgery, there was no evidence of recurrence or metastasis.

LESSONS

NF grows rapidly and has pathological features similar to sarcoma, making differential diagnosis difficult at the time of incisional biopsy. Further studies should be conducted to determine the clinical and pathological features of this tumor.

Inflammatory myofibroblastic tumor manifesting as recurrent generalized gingival enlargement: Report of a rare case

Oral inflammatory myofibroblastic tumor (IMT) is extremely rare and its manifestation as generalized gingival enlargement (GGE) has never been reported. We are reporting the case of 50-year-old female patient presenting with recurrent GGE for 4 years. Panoramic radiograph revealed severe bone loss in posterior sextants and root resorption in some teeth. Initial incisional biopsy was suggestive of chronic inflammatory infiltrate with fibrocollagenous tissue. Definitive treatment comprised of surgical excision of the enlarged gingiva with a tapering dose of steroid therapy. Histopathological and immunohistochemical examination from a repeat biopsy of deeper tissues was suggestive IMT. No recurrence was found at 2 years follow up. Recurrent GGE with advanced bone loss and external root resorption should raise the suspicion of a locally aggressive lesion. Dentists should be aware of oral IMT and include it in differential diagnosis of gingival enlargements for comprehensive management to avoid recurrence of the lesion.

Over expression of CDK4 and MDM2 in a patient with recurrent ALK-negative mediastinal inflammatory myofibroblastic tumor: A case report

RATIONALE

The diagnosis of anaplastic lymphoma kinase (ALK)-negative inflammatory myofibroblastic tumors (IMT) remains challenging because of their morphological resemblance with spindle cell sarcoma with myofibroblastic characteristics.

PATIENT CONCERNS

A 69-year-old female patient presented with loco-regional recurrent IMT several times within 8 years after primary treatment and neck lymph node metastasis 3.5 years after last recurrence.

DIAGNOSIS

The primary, recurrence, and lymph node metastasis lesions were diagnosed as ALK-negative IMTs based on the histopathological features.

INTERVENTIONS

Biopsy samples were obtained during repeated surgeries and evaluated for genomic alterations during first and recurrent presentations. The evaluation was done using pathway-driven massive parallel sequencing, and genomic alterations between primary and recurrent tumors were compared.

OUTCOMES

Copy number gains and overexpression of mouse double minute 2 homolog (MDM2) and cyclin dependent kinase 4 (CDK4) were observed in the primary lesion, and additional gene amplification of Discoidin Domain Receptor Tyrosine Kinase 2 (DDR2), Succinate Dehydrogenase Complex II subunit C (SDHC), and thyroid stimulating hormone receptor (TSHR) Q720H were found in the recurrent tumors. Metastases to the neck lymph node were observed 3.5 years after recurrence.

LESSONS

Our results indicated genetic evolution in a microscopically benign condition and highlighted the importance of molecular characterization of fibro-inflammatory lesions of uncertain malignant potential.

Identification Of Actionable Genetic Targets In Primary Cardiac Sarcomas

BACKGROUND

Primary cardiac tumors are extremely rare; most are myxomas with a benign prognosis. However, primary sarcomas are highly aggressive and treatment options are limited. Radical surgery is often not feasible and conventional therapies provide only modest results. Due to the rare nature of primary cardiac tumors, there are no proper randomized studies to guide treatment. Their complexity requires alternative approaches in order to improve treatment efficacy.

METHODS

We isolated DNA from 5 primary cardiac sarcomas; the quality of DNA from 3 of them was sufficient to perform high-resolution single nucleotide polymorphism (SNP) array analysis.

RESULTS

In the present study, molecular karyotyping revealed numerous segmental chromosomal alterations and amplifications affecting actionable genes that may be involved in disease initiation and/or progression. These include chromosomal break flanking AKT2 in undifferentiated pleomorphic rhabdomyosarcoma, chromosomal break in promoter of TERT, and gain of CDK4 and amplification of MDM2 in inflammatory myofibroblastic tumor. We detected segmental break flanking MOS in high-grade myxofibrosarcoma. In addition, the high number of chromosomal aberrations in high-grade myxofibrosarcoma may cause multiple tumor-specific epitopes, supporting the study of immunotherapy treatment in this type of aggressive tumor.

CONCLUSION

Our results provide a genetic rationale that supports an alternative, personalized therapeutic management of primary cardiac sarcomas.

Vocal cord inflammatory myofibroblastic tumor with mucoid deposits harboring TIMP3-ALK fusion: A potential diagnostic pitfall

A 35-year-old Japanese man who had experienced hoarseness for 10 years presented with a vocal cord lesion. A gross examination revealed a left vocal cord polyp occupying two-thirds of the vocal space. The endoscopically resected lesion contained scattered atypical fibroblastic, stellate, or ganglion-like cells with mucoid stroma. Vacuolated cells were also seen. Lymphoplasmacytic infiltrate was largely undetectable. A vocal cord polyp was first suspected, but well-differentiated liposarcoma and inflammatory myofibroblastic tumor (IMT) were included in the differential diagnoses. The tumor cells were positive for anaplastic lymphoma kinase (ALK), calponin, and vimentin, and negative for other smooth muscle markers by immunohistochemistry. Structures resembling myofibroblasts were not observed by electron microscopy, which confirmed abundant rough endoplasmic reticulum in the tumor cells and accumulated lipid droplets in some tumor cells. ALK gene rearrangement was detected by fluorescence in situ hybridization, and TIMP3-ALK fusion was confirmed by 5' rapid amplification of cDNA ends. We diagnosed the lesion as an IMT, and an ALK-rearranged stellate cell tumor may be postulated. This is the first report of a fusion partner gene of ALK in a case of laryngeal IMT.

Inflammatory myofibroblastic tumour of the jaw: A rare presentation

Inflammatory Myofibroblastic Tumour (IMT) is a rare entity of unknown aetiology and pathogenesis. It was initially described in the lung, although there have been reported cases affecting extra-pulmonary sites. The aetiology of IMT remains unclear, with current evidence suggesting that IMTs are neoplastic processes resulting from chromosomal translocations that often cause an overexpression of ALK tyrosine kinase. Histologically, a variably cellular myxoid morphology is common in these tumours, with the presence of inflammatory cell infiltrate. Clinically, symptoms are non-specific, although the presence of a swelling is frequently reported. Imaging studies are not very useful in the diagnosis, as they only describe the presence of a mass, and do not provide a definitive diagnosis. This article presents a case, of Inflammatory Myofibroblastic Tumour of the jaw, in a male patient aged 16 years.

Double amplifications of CDK4 and MDM2 in a gastric inflammatory myofibroblastic tumor mimicking cancer with local invasion of the spleen and diaphragm

Inflammatory myofibroblastic tumor (IMT) is currently recognized as an intermediate mesenchymal neoplasm. It can arise anywhere in the body, but it is particularly common in the lungs. Gastric IMT is very rare in adults. In this study, we report a case of a 68-year-old woman with IMT in the gastric cardia, with invasion into the spleen and diaphragm. Because of its location and aggressive clinical features, it was first mistaken for gastric cancer. However, pathology and immunohistochemistry were used to finally confirm the diagnosis of IMT after total resection of the tumor and spleen and partial resection of the diaphragm. In order to provide better understanding of this rare tumor, targeted next-generation sequencing (NGS) and IHC were performed to assess genetic and protein abnormalities of the tumor. Both IHC and NGS were found to be negative for ALK or other gene fusions. However, double amplification of CDK4 and MDM2 were found by NGS, and IHC also found CDK4 and MDM2 to be positive. To the best of our knowledge, this is the first gastric IMT report to show double invasion of the spleen and the diaphragm, and double amplification of CDK4 and MDM2 in IMT are also reported for the first time. This genomic aberration with protein overexpression is the most likely tumorigenic driver of this rare and aggressive tumor.

Treatment-refractory ALK-positive inflammatory myofibroblastic tumour of the oral cavity

We present a challenging case of a previously healthy 23-year-old man who developed an inflammatory myofibroblastic tumour of the hard palate, harbouring a rearrangement of the anaplastic lymphoma kinase (ALK) locus. Despite surgical intervention, radiotherapy and ALK-inhibition therapy, the tumour recurred locally and metastasised to regional lymph nodes, and the patient passed away roughly 9 months after diagnosis from local progression. The rapid progression of this patient's disease and its resistance to treatment demonstrate the potentially aggressive clinical course of inflammatory myofibroblastic tumours. ALK-inhibition therapy was unsuccessful in this ALK-positive tumour, highlighting the need for further investigation of markers predictive of disease progression and treatment response.

Inflammatory Myofibroblastic Tumor of the Tongue. Report of a Pediatric Case and Review of the Literature

BACKGROUND

Inflammatory myofibroblastic tumor (IMT) is an uncommon mesenchymal lesion composed of myofibroblastic and fibroblastic spindle cells, accompanied by inflammatory infiltration. IMT may occur in the tongue. Five cases have been previously reported at this site.

CASE REPORT

An inflammatory myofibroblastic tumor arose in the tongue of a 10 month old infant, confirmed by anaplastic lymphoma kinase (ALK) immunohistochemical staining and the clinical response to the tyrosine kinase inhibitor.

CONCLUSIONS

IMT can occur in the tongue. This report highlights the differential diagnosis of IMT. ALK staining is both a helpful diagnostic marker and a predictive marker for targeted therapy in this tumor type.

Inflammatory myofibroblastic tumour: A case report and a clinical update

The Inflammatory myofibroblastic tumor (IMT) is a heterogeneous group of rare lesions consisting predominantly of inflammatory cells and myofibroblastic spindle cells. Head and neck IMTs account for 14 to 18% of extra-pulmonary IMTs [lungs being the most commonly affected regions]. On account of its ambiguous clinical presentation, an IMT needs to be differentiated from other infectious, granulomatous, autoimmune and neoplastic lesions on the basis of histopathologic findings and immunohistochemical analysis. In this article, we report a case of IMT that presented in the anterior mandible that was treated by peripheral resection. Follow-up at 1 year showed satisfactory healing and no signs of recurrence. A special emphasis has been placed on the disputed nosology of this lesion and the latest therapeutic modalities.

Inflammatory myofibroblastic tumor of mandible: A rare case report and review of literature

Inflammatory pseudotumor is a term given to different neoplastic and nonneoplastic entities that have a common histological appearance, which comprises spindle cell proliferation with a prominent chronic inflammatory cell infiltrate. Inflammatory myofibroblastic tumor (IMT) is an uncommon lesion with distinctive clinical, pathological and molecular features and is considered to be pseudotumor for the past two decades due to its appearance. IMT is an intermediate soft tissue tumor which was first observed in lungs. It was named as IMT because it mimics a malignant neoplasm clinically, radiologically and histopathologically. The most common sites are lungs, liver and gastrointestinal tract. IMT in head and neck region is exceptionally rare and the sites reported include gingiva, tongue, hard palate, mandible, buccal mucosa and submandibular salivary gland. Till now, 8 cases of intramandibular IMT were reported. Here, we report an additional case of intramandibular IMT in a 20-year-old male patient.

Intraosseous inflammatory myofibroblastic tumor of the mandible with a novel ATIC-ALK fusion mutation: a case report

Background

Inflammatory myofibroblastic tumor (IMT) is a rare low-grade malignant neoplasm with a predilection for children and young adults, and typically arises in the lung, abdominopelvic region, and retroperitoneum. IMTs in the maxillofacial region are extreme rare. Approximately 50% of IMT harbor rearrangements of the anaplastic lymphoma kinase (ALK) gene at 2p23 with various fusion partners.

Case presentation

We herein report a case of intraosseous IMT of the mandible with a novel ATIC-ALK fusion. Tooth 43 did not erupt after the loss of tooth 83 in an 11-year-old girl with no previous history of trauma. Panoramic tomography showed a unilocular radiolucent lesion in the right anterior mandible resorbing the root of tooth 42 and the medial side of the root of tooth 44. Computed tomography revealed a well- circumscribed 3-cm osteolytic lesion of the right anterior mandible eroding the buccal cortical plate. The entire lesion was curetted out. A histopathological examination revealed the proliferation of plump spindle cells with a storiform architecture and lymphocytes scattered around spindle cells. The spindle cells showed diffuse cytoplasmic staining for ALK by immunohistochemistry. A fluorescence in situ hybridization analysis revealed the translocation of a part of the ALK gene locus at chromosome 2p23. A rapid amplification of cDNA ends analysis confirmed the rearrangement of ALK and identified ATIC as a partner of this ALK fusion mutant.

Conclusion

To the best of our knowledge, this is the first case of intraosseous IMT of the mandible with a novel ATIC-ALK fusion. We also herein reviewed similar tumors reported in the literature.

Intraosseous inflammatory myofibroblastic tumor in the mandible: a rare pathologic case report

Inflammatory myofibroblastic tumor (IMT) is an extremely rare lesion found in the maxillofacial region. Its frequency diminishes further when found in the bone. Although classification has varied throughout its history, the histologic features are often diagnostic, particularly with its strong association with anaplastic lymphoma kinase-1 (ALK-1) staining. The current mode of treatment for such a lesion is surgical removal with careful followup. In this rare case report, we describe the diagnosis and treatment in a 16-year-old male. Although this rare pathology can present as—and at times mimic—more serious pathologies, it is important for the attending surgeon to initially manage the pathology conservatively.

Inflammatory myofibroblastic tumor of maxilla showing sarcomatous change in an edentulous site with a history of tooth extraction following periodontitis: A case report with discussion

Inflammatory myofibroblastic tumor (IMT) is a rare tumor of uncertain origin with variable biological behavior ranging from reactive lesions to highly aggressive malignancy. Oral IMTs are extremely rare and only 25 cases had been reported so far. A case of IMT with sarcomatous transformation in an extraction site with a history of tooth extraction following tooth mobility of an upper left molar tooth is presented here. The tooth was extracted following a complaint of gingival swelling and mobility of tooth. Though malignant transformation in IMTs had been documented in the extra oral sites, wide search of associated literature suggests, this is the first case of oral IMT showing malignant change associated with gingiva. The case report attempts to highlight the variant possibilities of tooth mobility other than periodontitis and the importance of assessing the primary cause of such conditions.

Inflammatory myofibroblastic tumor: a rapidly growing soft tissue mass in the posterior mandible

The term inflammatory myofibroblastic tumor (IMT) encompasses a diverse group of spindle cell entities that traverses a clinical and histologic spectrum, extending from reactive to benign neoplastic to highly aggressive with malignant inclinations. Head and neck IMTs are rarely seen and comprise less than 5 % of tumors. Here we report a case of a 30 year old male who presented with a rapidly enlarging and extremely painful growth in the right posterior mandible, post extraction. Histopathological examination revealed a highly cellular connective tissue stroma comprised of spindle shaped cells arranged in fascicles, admixed with inflammatory cells, predominantly plasma cells. Apart from routine hematological investigations, serum protein electrophoresis was also performed. The final diagnosis was confirmed by a panel of immunomarkers consisting of MPO, CD34, CD20, CD3, CD23, CD138, SMA and ALK. To the best of our knowledge, this is the third case of oral IMT arising from an extraction socket.

Inflammatory myofibroblastic tumor of parotid in infancy--a new entity

Inflammatory myofibroblastic tumor is commonly found in lungs, mesentery or omentum in the younger population. We hereby report a hitherto unreported case of inflammatory myofibroblastic tumor, arising from the parotid gland in an infant. Diagnosis by histopathology and its treatment by superficial parotidectomy is being presented.

Inflammatory myofibroblastic tumor of the lung and the maxillary region: a benign lesion with aggressive behavior

Inflammatory myofibroblastic tumor (IMT) is a rare mass-forming lesion characterized by fibroblastic or myofibroblastic spindle cell proliferation with varying degrees of inflammatory cell infiltration. Although it has been reported in virtually every organ in the body, the lung is the most common site of involvement. Extrapulmonary IMTs, although rare, have been reported and are characterized by different, more aggressive behavior. We report an extremely rare case of maxillary metastases of pulmonary IMT. Lung IMT was initially misdiagnosed, and oral lesion mimicked clinically and radiologically a radicular cyst. On histologic examination, cells exhibited diffuse and intense immunoreactivity for α-smooth muscle actin and vimentin whereas both pulmonary and oral IMTs presented absence of cellular atypia and lack of expressivity of oncogenic determinants. Distant metastases of lung IMT are extremely unusual, and this is the first report to our knowledge with this particular clinical course. Despite the possibility that the present case could also represent a metachronous multifocal IMT, with pulmonary and extrapulmonary lesions, similar histopathological and immunohistochemical patterns in lung and maxillary region suggest a metastatic course.

An inflammatory myofibroblastic tumour of the breast with ALK overexpression

Inflammatory myofibroblastic tumours (IMTs), also known as inflammatory pseudotumours, include a diverse group of lesions characterised by inflammatory cell infiltration and variable fibrotic responses. Their occurrence in the breast is unusual. We present a case of an IMT of the breast in a 46-year-old woman who complained of a breast mass with palpable axillary lymph node. The initial clinical diagnosis was breast cancer, and the patient underwent a conservative excision with apparently negative margins and an axillary lymph node excisional biopsy. A histopathological examination showed the presence of myofibroblastic spindle cells with mixed inflammatory infiltrates, and the pathological diagnosis was IMT. Significantly, the case we present here is unique in showing anaplastic lymphoma kinase 1 (ALK1) overexpression and ALK1 gene amplification in IMT of the breast. Therefore, our case suggests that ALK1 gene amplification in IMT of the breast has important diagnostic and therapeutic implications.

Head and neck inflammatory myofibroblastic tumor (IMT): evaluation of clinicopathologic and prognostic features

Owing to rarity and awareness deficiency towards inflammatory myofibroblastic tumor (IMT), we sought to review on its clinicopathological features; arising awareness to achieve early diagnosis; exploring prognostic factors and then establishing a treatment protocol. Retrospective study was performed on patients with histological proven IMT between January 2003 and December 2010. Their demographic data, clinical and histological presentations were recorded. Overall survival (OS) and progression-free-survival (PFS) were estimated via Kaplan-Meier method. Cox regression model was applied to determine the significant of prognostic factors. Logistic regression model was established to predict the probability of relapse. A total of 28 patients. Five-year PFS was 65%. Surgical margins primarily and independently determined the survival, followed by size, pseudocapsule of the lesion, intra-lesional necrosis and lastly Ki-67 and ALK overexpression. Logistic model in prediction of relapse was established, with the formula as probability of relapse = 1/(1 + e(-z)) where e = exponential function, z = constant value (3.9) + B*margin + B*size + B*immunohistochemical expression + B*pseudocapsule + B*intra-lesional necrosis. Immunohistochemical overexpression was significant if Ki-67 was strongly expressed with a conditioned ALK overexpression simultaneously. Staining intensity must be at least moderate for those ALK nuclear staining was less than 25%. Weak ALK staining intensity is only significant if nuclear staining was more than 25%. Diagnosis of IMT is achieved via exclusion. Radical resection and obtaining negative margins remains the mainstay of treatment. Both high and moderate-risk groups required post-operative radiotherapy. In low-risk group, post-operative radiotherapy was recommended if the lesion is larger than 5 cm in diameter with a conditioned ALK & Ki-67 overexpression.

The effects of acrylamide on the frequency of megakaryocytic emperipolesis and the mitotic activity of rat bone marrow cells

BACKGROUND

Although the pathophysiological importance of emperipolesis is not known exactly, it has been reported to increase significantly in cases of various cancer types, different tumours and thrombosis disorders. In this study the effects of acrylamide on the frequency of megakaryocytic emperipolesis and the mitotic activity in rat bone marrow cells were determined. For this purpose, two separate experiments were performed with Sprague-Dawley rats gavaged with 0, 30, 45 and 60 mg acrylamide kg⁻¹ body weight (BW) for five consecutive days. In the second experiment, 3 mg colchicine kg⁻¹ BW was injected intraperitoneally 2 h before cervical dislocation. Bone marrow samples were taken 24 h after the last application in both experiments.

RESULTS

It was found that only the highest dose of acrylamide significantly decreased the incidence of megakaryocytic emperipolesis and that the types of bone marrow cells engulfed by megakaryocytes were mostly neutrophil granulocytes. Neither megakaryocytes nor engulfed cells showed any morphological degeneration. In the mitotic activity experiment, doses of 45 and 60 mg acrylamide kg⁻¹ BW decreased the mitotic activity of bone marrow cells in comparison with the control group.

CONCLUSION

It was concluded that the decrease in megakaryocytic emperipolesis frequency might be a consequence of the decrease in mitotic activity in bone marrow cells.

Postaural inflammatory pseudotumor: an extremely unusual complication of trauma in a child

We report the case of a 12-year-old boy who presented with a rapidly enlarging, painless mass behind the ear following trauma to the area. The mass was excised, and histopathologic and immunohistochemical evaluations revealed it to be an inflammatory pseudotumor. At 1 year postoperatively, the child exhibited no evidence of recurrence.

The immunohistochemical profile of oral inflammatory myofibroblastic tumors

OBJECTIVE

The aim of this study was to demonstrate the immunohistochemical profile of oral inflammatory myofibroblastic tumors (IMTs) along with morphologic analysis.

STUDY DESIGN

Three cases diagnosed as oral IMTs were selected to compile an immunohistochemical panel constituted by calponin, caldesmon, Bcl-2, desmin, fibronectin, CD68, Ki-67, S100, anaplastic lymphoma kinase (ALK), α-smooth muscle actin, cytokeratins AE1/AE3, muscle-specific actin, CD34, and vimentin. An oral squamous cell carcinoma with a focal area of desmoplastic stroma was used as control for the stained myofibroblastic cells.

RESULTS

All oral IMTs were positive for calponin, revealing a strong and diffuse expression in the spindle-shaped cells. The lesions were also positive for vimentin (3/3), fibronectin (3/3), α-smooth muscle actin (3/3), and muscle-specific actin (1/3) and negative for h-caldesmon, Bcl-2, desmin, CD68, Ki-67, S100, ALK, cytokeratins AE1/AE3, and CD34.

CONCLUSIONS

Within the results encountered, the present panel should be of great assistance in the diagnosis of oral IMTs.

Oral inflammatory myofibroblastic tumor: case report and review of literature

Inflammatory myofibroblastic tumor (IMT) is a rarely described tumor of unknown etiology and pathogenesis. It occurs primarily in the lungs, but has occurred in other extra-pulmonary sites. Histologically these lesions appear as an inflammatory infiltrate within a variably myofibrotic background. Current evidence shows that inflammatory myofibroblastic tumors are neoplastic processes resulting from chromosomal translocations that often cause an overexpression of ALK kinase, which is often assessed using immunohistochemical studies. Currently, the biological behavior of oral inflammatory myofibroblastic tumor is still uncertain. This article describes the clinical, histological, and operative features of a case of IMT of the oral cavity.

Inflammatory pseudotumor: report of a case in the mandible

BACKGROUND

Intraoral inflammatory pseudotumor (IPT) is a rare, benign non-neoplastic lesion that presents as a rapidly growing mass with aggressive behavior, which can be mistaken for a malignant process.

CASE REPORT

This article presents a rare case of IPT of the mandible in a 70-year-old male patient. Examination of the oral cavity revealed a hemorrhagic soft mass of the mandibular region. The patient was treated with surgery. Histologic examination of the resected specimen showed proliferation of fascicular spindle cells and a dense, chronic inflammatory cell infiltrate consisting of neutrophils, eosinophils, and lymphocytes. Immunohistochemically, the spindle cells expressed vimentin, α smooth muscle actin, and CD68, indicating a diagnosis of IPT.

DISCUSSION

IPT is an unusual benign pathology in the oral and maxillofacial area. Because of its aggressive clinical and radiological features, it can be mistaken for a malignancy. We suggest that oral and maxillofacial surgeons should be aware of the specific features of IPT to avoid unnecessary aggressive treatments such as a radical resection.

A successfully treated inflammatory myofibroblastic tumor of the mandible with long-term follow-up and review of the literature

Inflammatory myofibroblastic tumor (IMT) of the oral cavity is an extremely rare clinical and pathological disease entity. It was originally described in the lung but has recently been reported in various anatomic sites. We report such a case of inflammatory myofibroblastic tumor of the mandible in a 14-year-old girl. The patient presented with an aggressive ulcerative soft tissue mass of 3 months duration in the mandibular molar gingiva. Histologically, the lesion was composed of fibroblastic or myofibroblastic spindle cell proliferations with infiltrative margins in an inflammatory background. Immunohistochemically, the fibroblastic or myofibroblastic spindle cells were positive for vimentin, α-smooth muscle actin, and Ki-67 (MIB-1) but negative for desmin, pan-cytokeratin, S-100 protein, CD34, CD68, CD99, bcl-2, β-catenin, estrogen receptor, progesterone receptor, ALK-1, and p53. These spindle cells were focally and weakly Ki-67- (MIB-1-) positive. The MIB-1 labeling index was 5%. The results of in situ hybridization for Epstein-Barr virus-encoded-RNA were negative. The ratio of IgG4+/IgG+ plasma cells was about 10%. A pathological diagnosis of inflammatory myofibroblastic tumor was made. The postoperative course was uneventful, and the patient has had no recurrence in the 10-year follow-up period. Although no evidence of oral inflammatory myofibroblastic tumor recurrence or malignant transformation has been reported, it has been observed that in inflammatory myofibroblastic tumors of other regions, a prolonged follow-up is necessary after surgical resection. No other case of an IMT patient under 20 years of age has appeared in either the English or the Japanese literature.

RANBP2 and CLTC are involved in ALK rearrangements in inflammatory myofibroblastic tumors

Inflammatory myofibroblastic tumors (IMTs) are rare soft tissue tumors occurring primarily in children and young adults. ALK gene rearrangements have been identified in this neoplasm, with fusion of the ALK gene at 2p23 to a number of different partner genes. Metaphase cytogenetic analyses of these tumors have been relatively few, however, and may help to identify additional variant partners. We report on an IMT from a 2-year-old boy with a karyotype of 45,XY,der(2)inv(2)(p23q12)del(2)(p11.1p11.2),-22. FISH showed ALK-RANBP2 fusion in this tumor. The breakpoint was cloned and the fusion was confirmed, making this the third reported case of IMT with ALK-RANBP2 fusion. In addition, we identified the ALK fusion partner in a previously reported IMT with t(2;17)(p23;q23) as CLTC, a gene reported to be involved in four other IMTs, and showed that the breakpoint involved a novel ALK-CLTC fusion. FISH evaluation of nine other IMTs identified CLTC as the fusion partner in one additional case, but RANBP2 was not involved in the remaining eight IMTs, suggesting that the variant partners involved in ALK rearrangements in IMTs are diverse.

Significance of inflammatory pseudotumors in patients with a history of bladder cancer

OBJECTIVE

To study the significance of inflammatory pseudotumor (IPT) in patients with a history of bladder cancer.

METHODS

We surveyed our hospital database for patients who developed IPT during follow-up of bladder cancer. The original histologic blocks were reviewed and immunostained for vimentin, anaplastic large cell lymphoma (ALK), and pancytokeratin.

RESULTS

Between the years 1988 and 2005, a total of 809 patients were registered in the database, and 16 patients (2%) developed IPT during follow-up. All patients had initial high-grade tumor. Immunostaining for vimentin was positive in all patients, ALK was negative in all patients, and pancytokeratin positive in only 2 patients. During follow-up, 12 patients (75%) developed tumor recurrence, 9 patients (56%) tumor progression, and 6 patients (37.5%) died of bladder cancer. Median period from the finding of IPT to tumor recurrence was 16 months, to progression 7 months, and to mortality 26 months.

CONCLUSIONS

The finding of IPT in a patient with a history of bladder cancer is associated with a high risk of tumor recurrence, progression, and cancer-related mortality. Second- and possibly third-look bladder biopsies should be considered. The unique characteristics of IPT in patients with a history of bladder cancer suggest that this is a separate disease entity.

Differential diagnosis of laryngeal spindle cell carcinoma and inflammatory myofibroblastic tumor--report of two cases with similar morphology

Background

Spindle cell tumors of the larynx are rare. In some cases, the dignity is difficult to determine. We report two cases of laryngeal spindle cell tumors.

Case presentation

Case 1 is a spindle cell carcinoma (SPC) in a 55 year-old male patient and case 2 an inflammatory myofibroblastic tumor (IMT) in a 34 year-old female patient. A comprehensive morphological and immunohistochemical analysis was done. Both tumors arose at the vocal folds. Magnified laryngoscopy showed polypoid tumors. After resection, conventional histological investigation revealed spindle cell lesions with similar morphology. We found ulceration, mild atypia, and myxoid stroma. Before immunohistochemistry, the dignity was uncertain. Immunohistochemical investigations led to diagnosis of two distinct tumors with different biological behaviour. Both expressed vimentin. Furthermore, the SPC was positive for pan-cytokeratin AE1/3, CK5/6, and smooth-muscle actin, whereas the IMT reacted with antibodies against ALK-1, and EMA. The proliferation (Ki67) was up to 80% in SPC and 10% in IMT. Other stainings with antibodies against p53, p21, Cyclin D1, or Rb did not result in additional information. After resection, the patient with SPC is free of disease for seven months. The IMT recurred three months after first surgery, but no relapses were found eight months after resurgery.

Conclusion

Differential diagnosis can be difficult without immunohistochemistry. Therefore, a comprehensive morphological and immunohistochemical analysis is necessary, but markers of cell cycle (apart from the assessment of proliferation) do not help.