Presence of human herpesvirus-8 DNA sequences and overexpression of human IL-6 and cyclin D1 in inflammatory myofibroblastic tumor (inflammatory pseudotumor)

Pulmonary “inflammatory myofibroblastic” tumors: a critical examination of the diagnostic category based on quantitative immunohistochemical analysis

The World Health Organization classification applies the term "pulmonary inflammatory myofibroblastic tumor" to a histologically variegate set of pulmonary inflammatory pseudotumors. However, often these lesions bear little resemblance to tumors of myofibroblastic origin. To elucidate histogenesis, we examined 18 cases from our institution files. The cases were stained with antibodies to smooth muscle actin (SMA), Factor XIIIa, CD3, CD20, CD68, S-100, anaplastic lymphoma kinase (ALK-1), and human herpevirus-8 (HHV-8). The percentage of positive-staining cells within a defined tumor area (400,000 microm(2)) was determined by light microscopy and morphometric analysis. Ten cases (56%) showed myofibroblastic differentiation, as judged by positive SMA staining of spindle cells. All cases showed substantial numbers of CD68+, Factor XIIIa+, and S-100+ monocytoid cells. Fifty percent were ALK-1+, and one was HHV-8+. We conclude that the term "inflammatory myofibroblastic tumor" is a misnomer, as nearly half of cases show no myofibroblastic differentiation. Instead, the results suggest that these lesions are composed predominantly of cells of macrophage-dendritic cell lineage. Although the multiplicity of terms previously applied to these lesions is cumbersome, retaining a descriptive phenomenological terminology may ultimately promote accurate elucidation of pathogenesis.

Pulmonary inflammatory myofibroblastic tumor resected by video-assisted thoracoscopic surgery: Report of a case

Pulmonary inflammatory myofibroblastic tumor (IMT) is rare. A 38-year-old woman visited our hospital 2 days after experiencing transient anterior chest pain. Chest radiography showed a nodule suggestive of adenocarcinoma in the middle lobe; however, transbronchial lung biopsy and computed tomography (CT)-guided percutaneous needle cytology showed signs of inflammation. To obtain a definitive diagnosis we performed a wedge resection using video-assisted thoracoscopic surgery and removed the nodule completely. The pathologic diagnosis made during surgery was IMT. The longest dimension of the nodule was 28 mm. Immunohistochemical examination showed proliferating spindle cells, which were positive for vimentin and smooth muscle actin, but negative for desmin, CD34, cytokeratin, epithelial membrane antigen, S100 protein, and neuron specific enolase. These findings were consistent with the staining pattern of IMT previously reported. Careful follow-up is necessary to detect any sign of local recurrence and distant metastases.

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.

Absence of human herpesvirus-8 and Epstein-Barr virus in inflammatory myofibroblastic tumor with anaplastic large cell lymphoma kinase fusion gene

Inflammatory myofibroblastic tumor (IMT) is clinically and histologically characterized by inflammation. Some populations of IMT have anaplastic large cell lymphoma kinase (ALK) gene rearrangements. Infection with Epstein-Barr virus (EBV) and human herpesvirus-8 (HHV-8) in tumor cells of IMT has been reported; these reports, however, have been limited to ALK-negative IMT. The purpose of the present paper was to evaluate 21 cases of IMT for the presence of EBV and HHV-8. Immunohistochemically, 15 cases were ALK positive and six were negative. Of eight cases analyzed using reverse transcription-polymerase chain reaction, tropomyosin 3 (TPM3)-ALK, TPM4-ALK and clathrin heavy chain-ALK fusion genes were detected in one, two and two cases, respectively. All 21 IMT, irrespective of ALK expression, were negative for EBV by in situ hybridization for EBV-encoded RNA and immunohistochemical stain for latent membrane antigen-1. HHV-8 was also negative in all IMT by PCR for HHV-8 DNA sequence (KS330/233) and immunohistochemical stain for latent nuclear antigen. These results suggest that IMT may be a heterogeneous group in terms of pathogenesis, and EBV and HHV-8 do not play a major role in the pathogenesis of ALK-positive tumor.

Follicular localization of dendritic cells in a xanthomatous inflammatory tumor of lung associated with human herpes virus-8 infection

A 17-year-old man was treated with chemotherapy and radiation for nodular sclerosing Hodgkin lymphoma that presented as a left chest wall mass. Ten years later, a left upper lobe lung tumor was identified. The tumor resection demonstrated a 1.3-cm yellow lung nodule composed of epithelioid and spindled lipid-laden CD68+ and Factor XIIIa+ macrophages. Distinct follicular structures with dendritic cells positive for CD1a, fascin, and ALK-1 and largely devoid of intracytoplasmic lipid were a distinguishing feature of the lesion. Most of the xanthomatous macrophages expressed human herpes virus-8 antigen. The current World Health Organization classification of "inflammatory myofibroblastic tumors" is examined, and the association of a subset of "inflammatory pseudotumors" with immunodeficiency states and opportunistic infection is discussed.

Para-testicular cellular angiofibroma: a rare tumour in a male renal transplant patient

Cellular angiofibroma is a rare, benign, mesenchymal neoplasm that should be distinguished from other more aggressive mesenchymal lesions. A 32-year-old male presented with a painless para-testicular mass. Pathological examination showed features characteristic of cellular angiofibroma. He had a history of renal transplantation and was on immunosuppressive drugs. The pathogenesis of cellular angiofibroma is largely undetermined. The role of immunosuppressive therapy in the genesis of this tumour awaits further analysis.

Meningeal tumors of childhood and infancy. An update and literature review

Meningeal derived tumors of the first 2 decades of life are often diagnostically challenging due to the wide morphologic spectrum encountered and the rarity of most individual entities. The 2 most common patterns include the dural/leptomeningeal-based mass and neoplastic meningitis. Both primary and secondary meningeal presentations may occur, either early or late in the course of various meningothelial, mesenchymal, embryonal, glial, hematopoietic, histiocytic, melanocytic, and inflammatory tumors. As in other areas of pediatric pathology, there are significant differences between this patient cohort and adults, differences which will be emphasized in this review.

Hemorrhagic intracranial inflammatory pseudotumor originating from the trigeminal nerve: a case report

We report here on a case of intracranial inflammatory pseudotumor arising from the trigeminal nerve. A 52-year-old man presented with sudden onset severe headache. He had had facial numbness several months earlier and no signs indicating infection. On the computerized tomography scan, intracranial hemorrhage was detected at the cerebellopontine angle. Magnetic resonance imaging demonstrated a 2.7-cm-sized, homogenously enhancing mass. A provisional diagnosis of trigeminal schwannoma was made, and suboccipital craniotomy was then performed. The mass was encapsulated and had multiple capsular veins. There was a evidence of intratumoral bleeding. It originated from the trigeminal root and was adhered to the 4th cranial nerve. Pathologic examination showed fibrovascular tissue with dense infiltrates of plasma cells and lymphocytes, some histiocytes, and occasional neutrophils and eosinophils. It showed immunopositivity for leukocyte common antigen (LCA) and immunonegativity for S-100 and lysozyme. It was also immunopositive for EBV antigen. Intracranial inflammatory pseudotumors mostly arise from dural/meningeal structures in the intracranial location. This case is the first to describe an intracranial inflammatory pseudotumor originating from a cranial nerve. The pathologic examination supported the postinfection hypothesis out of several possible pathologic mechanisms.

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

Inflammatory myofibroblastic tumor (IMT) is a controversial lesion composed of myofibroblasts, accompanied by varying numbers of inflammatory cells. Various pathogenetic factors have been proposed (ie, reactive, infectious, autoimmune, and neoplastic) but the etiology of most IMTs remains unknown. Here we review the literature of oral IMTs, detailing the demographic profile of these rare lesions. Moreover, we present an unusual case of IMT arising from the mandibular alveolar mucosa of an 82-year-old female. Microscopic examination revealed plump spindle cells set in a myxoid vascular stroma admixed with inflammatory cells. Numerous large ganglion cell-like cells were seen, some exhibiting emperipolesis of neutrophils. Ultrastructurally, prominent myofibroblasts with abundant rough endoplasmic reticulum were noted. Tumor cells were immunoreactive for vimentin, smooth muscle actin, and KP1 (CD68), and negative for desmin, S-100, and EBV-LMP. The lesion was excised without margins and the patient has manifested no evidence of disease at an 18-month recall. In an attempt to further delineate the potential neoplastic nature of this lesion, we assessed the immunohistochemical expression of various markers that have been linked to neoplastic transformation. The recorded positivity for ALK, p53, MDM2, CDK4, pRb, and Ki-67, despite the absence of bcl-2 reactivity, strongly favors the neoplastic origin of the studied tumor.

Inflammatory myofibroblastic tumor with ALK/TPM3 fusion presenting as ileocolic intussusception: an unusual presentation of an unusual neoplasm

Inflammatory myofibroblastic tumor is a rare spindle cell lesion of indeterminate malignant potential occurring in both pulmonary and extrapulmonary tissues. This report describes an unusual presentation of an unusual tumor at an unusual location: an intramural ileal case of inflammatory myofibroblastic tumor presenting with intussusception in a 29-year-old woman. We characterize this tumor through microscopic and ultrastructural analysis, extensive immunohistochemical analysis, ploidy analysis, and Epstein-Barr virus in situ hybridization, and we report the finding of an ALK/TPM3 fusion using fluorescence in situ hybridization.

Inflammatory myofibroblastic tumor in children: clinical review with anaplastic lymphoma kinase, Epstein-Barr virus, and human herpesvirus 8 detection analysis

BACKGROUND/PURPOSE

Inflammatory myofibroblastic tumor (IMT) is considered as an intermediate neoplasm that may present malignant features. Differential diagnosis with other tumor processes is sometimes difficult. Similar anaplastic lymphoma kinase (ALK) gene abnormalities as in anaplastic large cell lymphoma have been reported. Human herpesvirus 8 (HHV-8) DNA sequences have been described in adult pulmonary IMTs and Epstein-Barr virus (EBV) has been reported in splenic and hepatic IMTs, suggesting the importance of both viruses in IMT development. This article aims to evaluate ALK, EBV, and HHV-8 expression in children with IMT and to correlate our findings with clinical features.

METHODS

Sixteen children (range, 1-15 years) who had surgery for IMT between 1978 and 2003 were evaluated retrospectively. Formalin-fixed, paraffin-embedded archival tissues were stained for HHV-8 and ALK with immunohistochemistry. Epstein-Barr virus was detected by in situ hybridization (EBER probes).

RESULTS

Tumors were located in the pulmonary lobe (n = 4), urinary tract (n = 4), mesentery or bowel (n = 4), hepatic lobe (n = 1), vena cava (n = 1), spinal cord (n = 1), and soft tissue (n = 1). Five children were treated with steroids and/or antibiotics before surgery, with no substantial result. IMT was excised totally in all but 2 cases. Four patients presented aggressive IMT with recurrence or metastasis requiring new surgery. ALK was positive in 3 (18.8%) cases and EBV in 1 pulmonary and 1 bladder tumor, all of them without recurrence or metastasis. None of the cases were positive for HHV-8. All patients are now disease-free with a mean follow-up of 4.2 years.

CONCLUSIONS

Considering the present lack of efficient medical treatment, surgery should still be considered as the mainstay therapy in IMT, even in cases of recurrence or metastases. Larger multicentric studies would be necessary to understand the prognostic significance of ALK, EBV, and HHV-8 and their relationships with the origins of the tumor.

Kaposi's sarcoma-associated herpesvirus: clinical, diagnostic, and epidemiological aspects

Kaposi's sarcoma-associated herpesvirus (KSHI) is one of the few viruses proven to be associated with tumorigenesis in humans. Its causal association with all clinical and epidemiological variants of Kaposi's sarcoma (KS) is well established. KSHV is also involved in the pathogenesis of primary effusion lymphoma (PEL) and a subset of multicentric Castleman's disease (MCD). Possible associations of KSHV with other clinical settings have been extensively examined. The findings from several of these studies are contradictory and are yet to be resolved. Concentrated effort over the last decade, since the initial discovery of KSHV, led to the development of several experimental systems that resulted in a better comprehension of the biological characteristics of KSHV and set the stage for the understanding of mechainisms by which diseases are induced by the virus. The development of molecular, histological, and serological tools for KSHV diagnosis allowed researchers to track the transmission and to study the epidemiology of KSHV. These assays have been applied, in particular in ambiguous cases, in order to confirm clinically and pathologically based diagnoses. Here, we review the advances in the clinical, experimental, diagnostic, and epidemiological research of KSHV.

So-called inflammatory myofibroblastic tumour: a proliferative lesion of fibroblastic reticulum cells?

The term inflammatory pseudotumour was originally used in a generic fashion for any lesion which simulated a neoplastic condition at a clinical, macroscopic and microscopic level but which was thought to have an inflammatory/reactive pathogenesis. In more recent times, the term has been employed in a more restrictive sense for a mass lesion characterized microscopically by the proliferation of a spindle cell component against a heavy inflammatory infiltrate of mixed composition but usually with a predominance of mature lymphocyte and plasma cells. The spindle cell component has generally been regarded as being of mesenchymal nature and having morphological and phenotypical features consistent with fibroblasts or myofibroblasts, the latter cell being clearly preferred over the former in the more resent reports. The term inflammatory myofibroblastic tumour (IMFT) is the one currently favoured, which proposes the myofibroblastic nature of the process. It is the purpose of this review to bring forth some evidence that the neoplastic spindle cell component of IMFT may be instead derived from the subtype of cells of the accessory immune system that have been variously called fibroblastic reticulum cells, myoid cells, and dictyocytes.

[Inflammatory pseudotumor of lymph node]

INTRODUCTION

Inflammatory pseudotumor of lymph node is a rare case in the etiology of fever of unknown origin.

OBSERVATION

We report the observation of a woman, aged 40, hospitalized with intermittent fever revealing under-diaphragm adenopathy related to inflammatory pseudotumor of lymph node.

CONCLUSION

Inflammatory pseudotumor of lymph node is a rare pathology whose nosological definition is unclear. It should probably be considered as belonging to a category different from the inflammatory pseudotumor of other organs. The diagnosis presents itself in case of isolated adenopathy or prolonged fever and is based on an anatomopathology that essentially calls to mind a lymphoma. The evolution of the condition is shown to be favorable : it can lead to a spontaneous remission, or call for a non-steroid anti-inflammatory treatment, or a steroid therapy.

Detection of KSHV in Transbronchial Biopsies in Patients With Kaposi Sarcoma

In transbronchial biopsies, Kaposi sarcoma (KS) is difficult to correctly diagnose by H&E staining due to the inherent vascular nature of the lung tissue, coupled with the subtle nature of the changes in early KS. Since KS-associated herpesvirus (KSHV) has been found in all clinical forms of KS, the detection of KSHV genomic DNA sequences and/or viral products may be helpful in the diagnosis of pulmonary KS. From their files during the past 10 years, the authors identified ten HIV/AIDS patients who were positive for KS in transbronchial biopsies and four HIV/AIDS patients with KS-negative transbronchial biopsies. Immunohistochemistry with antibodies against the latency-associated nuclear antigen (LANA-1 or LNA) of KSHV was performed. Nested polymerase chain reactions (PCR) with KSHV ORF-K1 or -K9 were performed in all cases, and the KSHV sequences were detected in 9/10 (90%) KS cases. Immunohistochemical analysis was able to detect 4/10 (40%) cases. One case was negative by both PCR and immunohistochemistry. Of the five KS cases that were not diagnosed definitively ("consistent with" or "suspicious for"), two were confirmed by both immunoreactivity and PCR. One of the negative control cases was positive for KSHV by PCR but not by immunohistochemistry. The patient was thereafter found to have a clinical history of pulmonary KS at another hospital. In conclusion, in transbronchial biopsies of the lung suspicious for KS, PCR is the most sensitive technique available for clinical diagnosis of KS. Immunohistochemistry analysis might be helpful in difficult pulmonary KS cases.

Inflammatory pseudotumour (plasma cell granuloma) arising in the maxillary sinus

CONCLUSIONS

Inflammatory pseudotumours in the maxillary sinus may present as malignant tumours and manifest locally aggressive features characteristic of such tumours. Despite their locally destructive features, they pursue a benign course after local excision.

OBJECTIVE

Inflammatory pseudotumour (plasma cell granuloma) is an uncommon non-neoplastic lesion comprising a proliferation of spindle myofibroblasts and chronic inflammatory cells. Despite its benign histopathological nature, it may exhibit aggressive behaviour that is yet to be characterized in the head and neck area.

MATERIAL AND METHODS

We present the cases of two adult patients with inflammatory pseudotumour arising from the maxillary sinus. Immunohistochemistry and polymerase chain reaction for immunoglobulin from tissue sections were performed to confirm the polyclonality of the infiltrating plasma cells.

RESULTS

CT and MRI disclosed expansive soft masses eroding surrounding soft and bony tissues. Histopathologically, the lesions were unencapsulated and composed of numerous plasma cells, histiocytes and spindle cells with minimal nuclear pleomorphism.

Human herpesvirus 8 (HHV8) sequence variations in HHV8 related tumours in Okinawa, a subtropical island in southern Japan

BACKGROUND

Although rare in mainland Japan, classic Kaposi's sarcoma (KS) is frequently reported in Okinawa, a subtropical island in southern Japan. Human herpesvirus 8 (HHV8) has been identified in the tumours and geographical differences occur.

AIM

To sequence HHV8 in classic and AIDS associated KS in Okinawa.

MATERIALS/METHODS

Eight classic KS cases, one AIDS associated KS, five granuloma pyogenicum cases, two inflammatory pseudotumours, two Castleman's disease cases, one angiosarcoma, and one primary effusion lymphoma (PEL) were studied. As a control, HHV8 positive cultured PEL cells (TY-1) were used. The presence of HHV8 sequences was evaluated by PCR and in situ hybridisation. PCR products were sequenced.

RESULTS

There were no histological differences among KS resulting from the different virus genotypes. HHV8 was detected in all cases of KS, in one PEL, and one granuloma pyogenicum. Eight classic KS cases and one granuloma pyogenicum were infected with HHV8 genotype II/C (K1 region) or subtype C (ORF26 region), which had a five amino acid deletion at K1 VR2 region. An AIDS associated KS and a PEL were infected with type I/A virus.

CONCLUSION

In Okinawa, classic KS cases and one granuloma pyogenicum case were infected with HHV8 genotype II/C, also classified as subtype C. AIDS associated KS and PEL were infected with a different HHV8 (genotype I/A), similar to that found in the USA. In Okinawa, HHV8 infection is more than four times higher than in mainland Japan, resulting in many cases of KS because of HHV8 genotype II/C infection.

Oligoclonal T-cell populations in an inflammatory pseudotumor of the pancreas possibly related to autoimmune pancreatitis: an immunohistochemical and molecular analysis

Inflammatory pseudotumors (IPT), also known as inflammatory myofibroblastic tumors (IMT), are benign inflammatory processes that may have an infectious etiology and are very rare in the pancreatico-biliary region. Recent studies suggest a biological distinction between IPT and IMT, the latter being a true neoplastic process. We describe a case of pancreatic IPT, originally diagnosed as malignancy, which presumably recurred 4 months after the operation. Histologically, the tumor consisted of a smooth muscle actin and CD68-positive spindle cell population and a more abundant mononuclear inflammatory cell population, primarily composed of macrophages and T-lymphocytes. Inflammatory cells were the source of connective tissue growth factor and transforming growth factor-beta1 and tended to accumulate around nerves and blood vessels, as well as around residual pancreatic parenchymal elements, where an intense angiogenetic response was detected. Comparative genomic hybridization analysis of the tumor showed no chromosomal imbalances. Polymerase chain reaction-based analysis of T-cell receptor gamma gene rearrangement revealed an oligoclonal pattern. These findings suggest that the pathogenesis of aggressive cases of IPT could be related to the development of an intense and self-maintaining immune response, with the emergence of clonal populations of T-lymphocytes. The relation of the pancreatic IPT to autoimmune pancreatitis is emphasized.

Pulmonary hyalinizing granuloma with laryngeal and subcutaneous involvement: report of a case successfully treated with glucocorticoids

We report a case of pulmonary hyalinizing granuloma (PHG) with laryngeal and subcutaneous involvement. A 43-year-old man was admitted to our hospital for assessment of hoarseness. Cervical and chest computed tomography, respectively, revealed a laryngeal tumor and two pulmonary masses. Specimens obtained from the pulmonary masses were compatible with PHG. The histopathology of biopsy specimens from both the laryngeal tumor and a subcutaneous tumor resembled that of the resected lung masses. Although there is no established treatment for PHG, the laryngeal tumor was diminished and all other lesions disappeared with glucocorticoid treatment.

Clinical and histological coexistence of inflammatory pseudotumour of the lymph nodes and rheumatoid arthritis

Inflammatory pseudotumour (IPT) of the lymph nodes is an uncommon, self-limiting, non-neoplastic proliferation of spindle cells, associated with a polymorphous inflammatory cell infiltrate embedded in a collagen-rich stroma and a variable degree of fibrosis, arising in the nodal parenchyma. Its clinical picture is characterised by site-specific signs and the presence, in most cases, of constitutional symptoms. The pathogenesis of IPT is unknown, but it has been interpreted as an aberrant reactive condition of the nodal connective framework, possibly related to viral infections or chronic inflammatory conditions. Its prognosis is usually favourable. We here report the simultaneous onset of seronegative rheumatoid arthritis (RA) and nodal IPT in a 31-year-old woman. Notably, in the nodal biopsy the coexistence of rheumatoid nodules, as well as histological and immunohistochemical features of IPT, was observed. To our knowledge, such an association has not been previously reported and the hypothesis that IPT could represent an unusual epiphenomenon of an RA-related chronic inflammatory response is suggested.

Inflammatory myofibroblastic tumour of paranasal sinuses with fatal outcome: reactive lesion or tumour?

Inflammatory myofibroblastic tumours (IMTs) are clinicopathologically distinctive but biologically controversial entities, which have been described in the lungs, abdomen, retroperitoneum, and extremities, but rarely affect the head and neck region. IMT usually follows a benign clinical course after radical excision, but invasive, locally recurrent, and metastatic forms of abdominal and mediastinal IMT have also been described. This report describes a case of IMT of the paranasal sinuses with a fatal outcome. A 22 year old woman was admitted to hospital as a result of epistaxis. Computed tomography scan and magnetic resonance imaging showed an expansive process in the paranasal sinuses, extending into the nasal cavity, orbita, and endocranium. The tumour progressed despite several surgical procedures. Radiotherapy, corticosteroids, and chemotherapy were unsuccessful, and the patient died four years after diagnosis, as a result of extensive intracranial spread of the tumour. This is the first known case of an IMT of the head and neck region with a fatal outcome. It shows that the aggressive behaviour of IMTs is not limited to abdominal and mediastinal locations, and supports recent observations that at least a subset of IMTs represents true neoplasia rather than reactive myofibroblastic proliferation.

Complex genomic rearrangement of ALK loci associated with integrated human Epstein-Barr virus in a post-transplant myogenic liver tumor

Epstein-Barr virus (EBV) is a ubiquitous viral agent, well known to be associated with lymphoid, epithelial, and smooth-muscle malignancies in immunocompromised individuals. This report describes a 10-year-old patient with an EBV-related liver tumor occurring after kidney transplantation. The neoplasm presented a phenotypic spectrum, ranging from a smooth-muscle tumor to an inflammatory pseudotumor (IPT). The neoplastic cells failed to disclose CD21, CD35, or ALK expression, the latter confirmed by reverse-transcription polymerase chain reaction. Cytogenetic analysis revealed a single clonal cell population showing 46,XY,del (2)(p23),der(3)t (2;3)(p23;q29),der(21) t(Y;21)(q12;p13) karyotype. By metaphase FISH analysis, the neoplastic cells demonstrated the presence of two molecularly different but related aberrant clones, one with the loss of one ALK allele and the second with translocation of the 3'end of ALK kinase domain on the der(3) chromosome. Using FISH with an EBV-specific and 3'end ALK DNA probes, a co-localization of the viral DNA and the ALK sequences was found on the der(3) chromosome. Metaphases with loss of rearranged ALK did not show integrated virus; instead, viral particles together with an associated 3'end ALK domain formed an ex-chromosomal, episomal-like type configuration. The interphase study, using dual-color 5'/3' end ALK FISH assay, revealed 30% of nuclei with only one fused signal, confirming the total loss of one ALK allele in the subset of tumor cells. A combined immunofluorescence and FISH study indicated this separate clonal variant to correspond to desmin-positive smooth-muscle cells. In contrast, desmin-negative myofibroblasts showed the presence of both normal and rearranged ALK alleles. Our results indicate that ALK locus may be a target of EBV integration, a hitherto unreported finding. Although the sustained clonal expansion in EBV-related smooth-muscle tumors/IPTs may depend on functions provided by the EBV oncogenic proteins, the tumor phenotype may be further modified by the secondary genomic rearrangements imposed by the virus during and/or after the integration event. In this respect, the observed phenotypic heterogeneity most likely reflects divergence during neoplastic progression, with the subsequent expansion of morphologically and molecularly distinct but cytogenetically related clones.

Inflammatory myoblastic tumor of the uterus and interleukin-6

We report a patient with inflammatory myoblastic tumor of the uterus with constitutional symptoms. Surgical excision was curative and brought a rapid normalization in the elevated serum level of interleukin-6. We revealed an overproduction of interleukin-6 by a detection of messenger RNA by use of reverse transcriptase-polymerase chain reaction and immunohistochemistry.

Intranodal palisaded myofibroblastoma with overexpression of cyclin D1

Intranodal palisaded myofibroblastoma (IPM) is a rare benign spindle-cell tumor of lymph nodes with myofibroblastic/smooth muscle differentiation. We present another case of IPM that confirms the myofibroblastic differentiation of the tumor cells and identifies the so-called amianthoid fibers as collagen deposits by immunohistochemical and ultrastructural techniques. Because IPM shares histomorphologic characteristics with an inflammatory myofibroblastic tumor that has been associated with a virus-induced alteration of cell cycle regulation, the diagnostic approach was extended in this case. We were able to demonstrate cyclin D1 overexpression but could detect neither amplification of the CCND1 gene nor allelic loss at chromosomes 9p22-21 and 13q (surrounding the genes p16 and Rb, respectively). Furthermore, no evidence of human herpesvirus-8 or Epstein-Barr virus infection could be found by polymerase chain reaction or immunostaining. Nevertheless, our results point to the cell cycle regulatory genes as a factor in the pathogenesis of IPM.

Correlation between transcranial interleukin-6 gradient and outcome in patients with acute brain injury

OBJECTIVE

This study was performed to examine both brain and systemic interleukin-6 (IL-6) release in patients with an acute brain injury (ABI), to study whether a correlation exists between the transcranial IL-6 gradient during the first days after injury and prognosis, and finally, to investigate the relationship between a nucleotide polymorphism at position -174 in the promoter of the gene encoding IL-6, IL-6 responsiveness, and clinical evolution.

DESIGN

Prospective clinical investigation.

SETTING

A 19-bed intensive care unit in a university hospital.

PATIENTS AND METHODS

A total of 62 patients were followed up for 3 days after acute brain injury, and both their arterial and jugular IL-6 levels were measured serially and at the moment of brain death diagnosis. Genetic polymorphism of IL-6 was also determined in all patients. Data were correlated with those from score procedures for clinical severity. Neurologic outcome was graded according to the Glasgow Outcome Scale 6 months after injury. IL-6 levels and IL-6 genotyping was performed in control healthy individuals.

MAIN RESULTS

There is a significant transcranial IL-6 gradient at admission and at the moment of brain death. The gradient is higher in those patients who evolved toward a fatal outcome during the first 6 months after injury (p <.001). There is significant correlation between the transcranial IL-6 gradient and the acute brain injury severity.

CONCLUSIONS

IL-6 is elevated in patients with acute brain injury, and a significant relationship exits between the severity of acute brain injury and the transcranial IL-6 gradient at admission. It can be considered to be a prognosis marker at admission. When data at the moment of brain death are considered, venous IL-6 (p <.01) and the transcranial IL-6 gradient (p <.005) are significantly higher than at the time of admission. Although the IL-6 C allele is associated with significantly lower concentrations of IL-6, there was no correlation between low or high IL-6 responders and patient outcome.

Inflammatory pseudotumors of the central nervous system: report of 3 cases and a literature review

Inflammatory pseudotumors (IPs), mostly benign lesions characterized by fibrotic ground tissue and polyclonal mononuclear infiltrate, may affect all organ systems. IPs originating in the central nervous system (IP-CNS) are very rare, and their distinct histopathologic features are poorly characterized. Three otherwise healthy patients (age 8, 15, and 17 years) presented with focal neurologic symptoms (seizures, n = 2; headaches, n = 1), corresponding to a left temporal, left occipital, and left frontal IP, respectively, extending from meningeal structures into brain tissue. After resection, no recurrence was observed in patient 1 during 5 years of follow-up, whereas patient 2 developed a rapidly progressive local recurrence and a second intracerebral lesion despite antiviral, immunosuppressive, antibiotic, and radiation therapy. In patient 3, who also showed local recurrences, sequential histopathologic investigations revealed transformation to a semimalignant fibrohistiocytic tumor. In this patient, anaplastic lymphoma kinase (ALK) expression was also positive, whereas it was negative in patient 1. A detailed literature analysis confirmed that most IP-CNS arise from dural/meningeal structures (n = 34). Intraparenchymatous (n = 7), mixed intraparenchymatous/meningeal (n = 4), and intraventricular lesions (n = 7) or IP extending per continuitatem from intracerebral to extracerebral sites (n = 5) were rare. The recurrence rate was 40% within 2 years in general. It was increased after incomplete resection and in female patients (multivariate Cox regression model, P < 0.02). Although rare, IP-CNS are important differential diagnoses among tumor-like intracranial lesions. Their potential risk of malignant transformation and high risk of recurrence necessitate close follow-up, especially when resection is incomplete. Prospective multicenter trials are needed to optimize classification and treatment of this rare inflammatory lesion.

Intravascular inflammatory myofibroblastic tumors in infancy

Inflammatory myofibroblastic tumor (IMT), previously described as inflammatory pseudotumor, can occur at any age but is a recognized soft tissue tumor of childhood. Less than 10 previous cases have been described of IMT affecting the heart, in patients ranging from 5 months to 17 years of age. We present three unusual, but similar, cases of IMT in infants, which were all predominantly intravascular in location, one of which was associated with death due to angiodestructive lesions of the coronary and cerebral arteries. These cases demonstrate an apparently distinct phenotype, with a predominant intravascular location of the tumor. Furthermore, this series highlights the difficulty in categorizing such lesions as benign versus malignant on histological grounds alone. IMT should be considered in the differential diagnosis of unusual pediatric intravascular spindle cell lesions.

Inflammatory pseudotumor of lymph node and spleen: an entity biologically distinct from inflammatory myofibroblastic tumor

Inflammatory pseudotumors (IPTs) of the lymph node and spleen are an uncommon, benign cause of lymphadenopathy and/or splenomegaly that often bear striking clinicopathologic similarities to the inflammatory myofibroblastic tumors (IMTs) found in soft tissues. These tumors have classically been grouped together under the umbrella category of "inflammatory pseudotumor." Recent evidence shows that IMTs are in fact neoplastic processes that often harbor balanced chromosomal translocations involving the ALK kinase gene. These translocations result in expression of ALK kinase in IMTs as assessed by immunohistochemical studies. However, the relationship between IMT and IPT of the lymph node and spleen is uncertain. To determine if ALK tyrosine kinase expression is also present in IPT, 13 cases of IPT (9 involving lymph nodes, 4 splenic lesions) were examined for the presence of ALK tyrosine kinase by immunohistochemical staining on paraffin-embedded tissue. In addition, in situ hybridization studies for Epstein-Barr virus--encoded RNAs (EBER) and immunoperoxidase studies for human herpesvirus-8 (HHV8)--specific proteins were performed. All cases had clinical, morphologic, and immunophenotypic findings typical of IPT and had varying proportions of fibroblastic and inflammatory components. Age ranged from 11 to 75 (median, 40) years; 8 subjects were male, and 5 were female. None of the cases (0 of 13) had positive staining for ALK kinase or HHV8, and in 1 a lymph node (1 of 13) was focally positive for EBV (EBER) by in situ hybridization. The absence of ALK kinase as detected by immunohistochemical studies in IPT of the lymph node and spleen suggests that this entity is biologically distinct from the histologically similar IMT.

The emerging role of the human herpesvirus 8 (HHV8) in human neoplasia

The human herpesvirus 8 (HHV8) was initially described and characterised in Kaposi's sarcoma tissue. The virus was found in the lesion of most cases of Kaposi's sarcoma. Whilst there is a large body of evidence to implicate its role in the pathogenesis of Kaposi's sarcoma, it has recently been found that the virus may also be important in a number of other human neoplasias. This review will examine the molecular pathology of HHV8 in the pathogenesis of Kaposi's sarcoma and summarise the current evidence and postulated mechanisms in its role in other human neoplasias.

Human herpesvirus-8 genes are expressed in pulmonary inflammatory myofibroblastic tumor (inflammatory pseudotumor)

The presence of human herpesvirus-8 DNA sequences, as well as an overexpression of human interleukin-6 and human cyclin D1 in myofibroblastic cells of inflammatory myofibroblastic tumor (inflammatory pseudotumor), has recently been reported. We describe the pattern of human herpesvirus-8 gene expression in five cases of pulmonary inflammatory myofibroblastic tumor. Reverse transcriptase-polymerase chain reaction (RT-PCR), with several positive and negative controls, was performed to detect mRNA of 11 open reading frames encoded by human herpesvirus-8 in lytic and latent stages of viral replicative cycle. We found molecular transcripts from ORF16, ORFK13, and ORF72 in the five cases and from ORFK2 in four of five neoplasms. The corresponding encoded proteins were human homologous oncoproteins (viral cyclin-D), inflammatory cytokines (viral IL-6), and inhibitors of apoptotic pathways (viral FLIP and viral Bcl-2), mostly expressed in a latent viral replicative stage. The rest of open reading frames examined included mainly lytic-associated genes and showed no expression. The spectrum of expressed viral genes is not the same as can be observed in Kaposi's sarcoma or multicentric Castleman's disease, suggesting that human herpesvirus-8 plays a different role in the pathogenesis of its associated diseases. These differences may be related to either cell-specific or immunologic host factors.