Malignant Reticulosis Research Articles

Availability of a Microglia and Macrophage Marker, Iba-1, for Differential Diagnosis of Spontaneous Malignant Reticuloses from Astrocytomas in Rats

In rats, it is sometimes difficult to distinguish malignant reticuloses from astrocytomas in routine histopathological assessment. In the present study, four spontaneous brain neoplasms developing in the cerebrum of one Wistar Hannover rat and three Sprague-Dawley rats were immunohistochemically examined using microglia and macrophage markers. Histopathologically, these neoplasms were localized mainly in the cerebral cortex, hypothalamus or piriform lobe, and the portions showing solid growth did not show characteristic cellular arrangement but had an indistinct boundary with the surrounding brain parenchyma. Neoplastic cells had oval or pleomorphic small nuclei with abundant eosinophilic cytoplasm. Two cases showed neoplastic cell infiltration into the meninges and perivascular spaces. Silver staining showed lack of reticulin fiber production in the stroma of the neoplasms. Immunohistochemically, the neoplastic cells were strongly positive for Iba-1 and sporadically positive for CD68 in all four cases. On the basis of these results, all the neoplasms examined here could be distinguished from astrocytomas and diagnosed as malignant reticuloses. Thus, immunohistochemical demonstration of microglia/macrophage characters, such as using Iba-1, is considered to be helpful for differential diagnosis of malignant reticuloses from astrocytomas among spontaneously occurring primary brain neoplasms in rats.

Histological and Immunohistochemical Studies on Spontaneous Rat Astrocytomas and Malignant Reticulosis

Among spontaneous neoplasms of the rat central nervous system, the discrimination between astrocytoma and malignant reticulosis (MR) is sometimes difficult because of their similar cell morphology and infiltration patterns. In the present study, we carried out histological and immunohistochemical analyses on a total of sixty-four cases in Sprague-Dawley and F344 rats. These cases were diagnosed as benign/malignant astrocytoma containing no neoplastic oligodendroglial elements or MR according to the diagnostic criteria of the World Health Organization International Classification of Rodent Tumors (Mohr et al. 1994). Astrocytomas were divided into three types and MR into two types based on the number of lesions, cellularity and infiltration patterns, and so on. Although the neoplastic cells from all types showed various immunoreactivities for RM-4 (anti-rat macrophages and dendritic cells), ED-1, and/or vimentin, there were no distinctive differences among these types, and most cells that were positive for RM-4 were also positive for ED-1. None of the tumor types showed any reactivity for GFAP or S-100 protein. From the results of morphological and immunohistochemical examinations, it was indicated that there are no distinctive differences between spontaneous astrocytomas and MR in rats, and they are probably derived from the same cell lineage, that is, microglia, macrophage, or radial glia.

Carcinogenicity: P14: Immunohistochemical study of astrocytoma and malignant reticulosis in rats

In rat spontaneous neoplasms of the central nervous system, the discrimination between astrocytoma and malignant reticulosis is sometimes difficult because of their similar cell morphologies and growth and infiltration patterns. The derivation of malignant reticulosis is proposed to be lymphocytes, microglias or histiocytes, although their precise origin has not been established yet. In the present retrospective study we examined immunohistochemical analyses from a total of 43 cases in Sprague-Dawley (SD) rats and 21 cases in F344 rats which were diagnosed as benign astrocytoma, malignant astrocytoma or malignant reticulosis according to the diagnostic criteria of WHO International Classification of Rodent Tumours (IARC No. 122). The tumours were classified into five categories as follows: (1) early stage of astrocytoma: 7 cases (SD: 3 cases, F344: 4 cases); they are composed of one lesion of moderate cellularity in the parenchyma. (2) common type of astrocytoma: 41 cases (SD: 29 cases, F344: 12 cases), which includes not only a single lesion with dense cellularity but also multiple extending lesions in the parenchyma, with infiltration into peripheral meninges or perivascular space. (3) glioblastoma type of astrocytoma: 12 cases (SD: 10 cases, F344: 2 cases); necrosis with peripheral palisading is observed. (4) intermediate type of astrocytoma and malignant reticulosis: 2 cases (SD: 1 case, F344: 1 case); neoplastic cells are infiltrated more diffusely in meninges and perivascular space with obvious parenchymal infiltration. (5) malignant reticulosis: 2 cases (both in F344); neoplastic cells are infiltrated diffusely in meninges and perivascular space without obvious parenchymal infiltration. The neoplastic cells from all categories showed various immunoreactivities for vimentin, RM-4 (anti-rat macrophages and interdigitating cells) and ED-1. However, no distinct difference among these categories was observed. The positive cells for RM-4 mainly corresponded to those of ED-1. The reactivity for vimentin was more intense than that of RM-4 and ED-1. A few neoplastic cells from the common and glioblastoma types demonstrated positive reaction for nestin. No reactivity for GFAP or S-100 was observed in any case of any category. Perivascular or intercellular reticulin fibers which were stained with Watanabe's silver impregnation method were observed in some or many cases in each category except for the early stage of astrocytoma. The results of the malignant reticulosis generally coincided with those of astrocytomas. In conclusion, no difference in the cell origin between astrocytoma and malignant reticulosis could be found.

Midline Malignant Reticulosis In Birnin Kebbi, Nigeria : A Case Report

We report the case of a 45-year old woman with a six-month history of persistent headache, right nasal obstruction, recurrent epistaxis and right eye swelling. Examination revealed obvious facial asymmetry, enophthalmos, right maxillary and zygomatic swelling with an intranasal mass exhibiting contact bleeding. Plain roentgenograms revealed erosion of the surrounding bones. Patient had right lateral rhinotomy to clear the tumour and arrest epistaxis. Histological examination of the biopsy revealed a polymorphic neoplasm composed of a mixture of small lymphoid cells and atypical large histiocytoid cells with foci of necrosis. These features were consistent with midline malignant reticulosis. This is a relatively rare condition and this is the first case recorded in this centre. Keywords: Midline malignant reticulosis; Histopathology; Rare Sahel Medical Journal Vol. 11 (3) 2008: pp. 102-104

Highly Invasive Intracranial Malignant Schwannoma in a Rat

A highly invasive intracranial malignant schwannoma containing several masses was detected in a 28-week-old male Crl:CD(SD) rat. Macroscopically, 3 masses were noted in the cranial cavity; one was present at the bottom of the cranial cavity and involved the trigeminal nerve, and the other two were in the parietal bone. Histologically, each mass consisted of fusiform cells with interlacing fascicular, wavy and nuclear pseudopalisading arrangements and round cells with cystic lesions. The tumor cells invaded not only the brain but also the parietal bone. In the brain, the tumor cells infiltrated diffusely into the leptomeningeal and perivascular spaces and parenchyma, in which the tumor cell morphology and invasive pattern closely resembled those of malignant astrocytoma and malignant reticulosis. Immunohistochemically, the tumor cells in the masses showed positive reactions for both S-100 protein and GFAP, while those in the cerebral invasion sites were negative for GFAP and less positive for S-100 protein. Electron microscopically, a single basal lamina layer and short intricate cell processes were confirmed in the tumor cells. From these results, the present tumor was diagnosed as a malignant schwannoma arising in the cranial cavity, probably originating from the trigeminal nerve. The present tumor is considered to be a relatively unique malignant schwannoma based on its growth and invasion patterns.

Body cavity-based presentation of natural killer cell lymphoma

We describe an unusual case of a 31-year-old Mexican woman who presented with pleural and peritoneal effusions involved by Epstein-Barr virus-positive non-Hodgkin's lymphoma of natural killer (NK)-cell lineage. The patient had no symptoms that could be related to her nasal region, and physical examination and radiologic studies showed no evidence of lymphadenopathy, organomegaly, or other extranodal masses. Thus, this case clinically mimicked body cavity-based lymphoma. Extranodal NK/T-cell lymphoma of nasal type is the current designation for these neoplasms in the recently proposed World Health Organization classification of lymphoid neoplasms. These tumors previously have been referred to many other names, including lethal midline granuloma, midline malignant reticulosis, polymorphic reticulosis, angiocentric immunoproliferative lesion, and angiocentric lymphoma. Nasal-type NK/T-cell lymphomas typically involve the nasal region, but may involve other extranodal sites, such as skin and gastrointestinal tract. The malignant cytologic features and the presence of azurophilic granules within the cell cytoplasm observed in Wright-Giemsa-stained cytocentrifuge preparations led to immunophenotypic and molecular genetic studies that were essential in establishing the correct diagnosis. As demonstrated in the case reported, extranodal NK/T-cell lymphomas of nasal-type can be clinically aggressive and may be associated with paraneoplastic phenomena.

Nasal Natural Killer/T-Cell Lymphoma

An 18-year-old man with a nasal NK/T-cell lymphoma had a midfacial destructive process. Sinonasal tract lymphomas represent heterogeneous diseases that can be clinically aggressive. Synonyms have included polymorphic reticulosis, lethal midline granuloma, midline malignant reticulosis, and idiopathic midline destructive disease. Although these terms have been used synonymously with sinonasal lymphomas, they are inaccurate and no longer valid. Nonneoplastic lesions, such as inflammatory and infectious diseases, as well as numerous benign and malignant neoplasms of the sinonasal tract, may all result in a destructive process occurring in the midline aspect of this region. The current designations for these nasal and paranasal sinus lymphomas include angiocentric immunoproliferative lesions, peripheral T-cell lymphomas, and more recently, nasal and nasal-type NK/T-cell lymphomas.

Diagnostic importance of the nucleolar organizer regions in Wegener's granulomatosis.

The number and distribution pattern of silver staining nucleolar organizer regions (AgNORs) were thought to reflect the cellular proliferative activity and the malignancy of tumours. Using a silver-staining method, the variations of AgNORs have been studied in patients with atypical inflammatory lesion (n = 5), malignant reticulosis (n = 5) and Wegener's granulomatosis (n = 6). Our results reveal that there was a statistically significant difference (p < 0.01), highly suggestive of a difference in AgNOR counts between the atypical inflammatory lesion and Wegener's granulomatosis, with the Wegener's granulomatosis specimens having the higher irregular AgNORs, but the difference between Wegener's granulomatosis and malignant reticulosis is probably not clinically important. It is concluded that AgNORs may be useful in differentiating Wegener's granulomatosis from an atypical inflammatory lesion, and the simplified counting technique is adequate for the purpose.

原発性鼻結核例

We encountered a 32-year-old Philippino man with primary nasal tuberculosis. He developed increasing nasal obstruction and persistent epistaxis. His general health was quite good and chest X-ray showed no abnormality in the lung field. A CT-scan showed no granulation or inflammation in bilateral paranasal sinuses.Granulomatous changes in the mucosa of the right inferior turbinate were the only finding. Biopsy of the inferior turbinate showed caseating granuloma. Finally, we diagnosed his illness as primary nasal tuberculosis because tubercle bacillus was identified using the polymerase chain reaction methods, which found to be useful in precisely diagnosing nasal tuberculosis.The differential diagnosis of nasal granulomatous disease usually includes Wegener's granulomatosis, midline malignant reticulosis, sarcoidisis and tuberculosis. However, tuberculosis of the nose has become so infrequent that it is a virtually forgotten disease. We point out the necessity of including tuberculosis in this differential diagnosis.

New Concepts in the Classification of Cutaneous Lymphomas

IN THIS ISSUE of theArchives, Friedmann et al 1 describe 11 patients with a primary cutaneous pleomorphic small T-cell lymphoma and suggest that this represents a new and distinct type of cutaneous T-cell lymphoma (CTCL). 1 These primary cutaneous pleomorphic small T-cell lymphomas represent only one of the many new types of cutaneous lymphomas that have been published over the last decade in the dermatologic literature. For many decades, mycosis fungoides (MF), Sezary syndrome, and related disorders such as pagetoid reticulosis and lymphomatoid papulosis (LyP) were the only types of cutaneous lymphoma that had been rather well defined. Reports on cutaneous lymphomas other than MF and/or Sezary syndrome were few. These lymphomas, commonly designated as malignant reticulosis or reticulum cell sarcoma, were generally regarded as manifestations of systemic lymphoma, and their prognosis was considered poor. 2-4 With the introduction of immunohistochemical studies in the diagnosis and classification of cutaneous

Effects of barbital on neuro-oncogenesis in a transplacental carcinogenicity model using F344 rats.

Effects of barbital (BB) on neuro-oncogenesis were examined in a rat transplacental carcinogenesis model. Pregnant F344 rats were divided into 7 groups. Dams in group I received subcutaneous injections of 10 mg/rat 1-butyl-1-nitrosourea (BNU) on the days 15, 18 and 21 of pregnancy and dams in groups II-IV, 1mg/rat BNU on the same time schedule. In addition to the treatment with BNU, dams in group IV were given 0.125% BB solution as their drinking water from the day 12 of pregnancy to parturition. Offspring in groups III and IV received 0.125% BB solution as drinking water from 4 weeks of age until the termination of the study. Animals in groups V and VI were given 0.25% and 0.125% BB solutions, respectively, in the peri- and postnatal period without BNU treatment. Dams in group VII received 250 mg/kg BB subcutaneously on the days 15, 18 and 21 of pregnancy. Offspring in all groups were observed until 105-116 weeks of age. High yields of neurogenic tumors, such as gliomas and neurinomas, were observed in group I. In groups II, III and IV, single cases of a chordoma, a granular cell tumor, and a neurinoma and a malignant reticulosis, which are known to occur spontaneously, were noted, although no gliomas were found. No neurogenic tumors were observed in groups V-VII. With regard to lesions other than those in neurogenic organs, a significant increase in liver tumors was observed in group III compared to group II. In contrast, lung tumors were not found in group III, while they were observed in groups II and IV. These results suggest that BB has no neuro-carcinogenic activity in the rat transplacental carcinogenesis model.

悪性細網症が合併した口底癌の１例

Head and neck cancers are frequently combined with other primary lesions in the head and neck area or in the digestive tract, especially the esophagus and stomach. Therefore, most multiple primary cancers are pathologically squamous cell carcinoma and adenocarcinoma.We report a case of carcinoma of the oral floor in a 69-year-old man with malignant reticulosis, which is one of the rare mesenchymal tumors. The primary carcinoma of oral floor was completely eradicated by chemotherapy and radiotherapy; however, the patient died from pancytopenia of unknown cause and multiple organ failure. Pathological examination at autopsy revealed squamous cell carcinoma of oral floor with malignant reticulosis involving the spleen, liver, bone mallow, lung and lymph nodes.

Midline malignant Granulomatosis

Midline malignant reticulosis (MMR) is the term proposed for a destructive midline lesion with a histological patern distinct from conventional lymphosarcoma and having similarity to Wegner’s Granulomatosis. The case is reported for its rarity.

Epstein-Barr virus in nasal T-cell lymphomas (polymorphic reticulosis/midline malignant reticulosis) in western China.

Polymorphic reticulosis (PR) or midline malignant reticulosis (MMR) is considered to be malignant, or at least pre-malignant T-cell proliferations of the nose or midline area. Recent reports of small series of nasal T-cell lymphomas have shown a strong association with Epstein-Barr virus (EBV). Furthermore, a peculiar phenotype is described, with expression of CD56 and not of CD3, suggesting a possible origin from natural killer (NK) cells. We have analysed a series of 38 cases of PR/MMR for the presence of EBV by in situ hybridization (ISH) of the EBV-encoded RNAs 1 and 2 (EBER). Twenty cases were tested for expression of EBV-encoded latent membrane protein 1 (LMP-1). Special attention was also paid to the expression of CD3 and the NK cell-related marker CD56. Thirty-two cases (84 per cent) showed positive EBER ISH. In 5 of 20 cases, LMP-1 expression was detected. In three cases, a few scattered cells were positive, and in two cases, LMP-1 was detected in clusters of atypical cells. Most of the neoplasms showed expression of CD3 (89 per cent) and in 27 cases (71 per cent), CD56 was detected. These results are consistent with an aetiopathogenetic role for EBV in most, but not all, cases of PR/MMR. Our findings are less supportive of a major role for LMP-1 in tumour genesis. CD3 expression in most of the cases of PR/MMR underlines the T-cell origin of these neoplasms, often with aberrant expression of CD56.

Nasal T-cell lymphoma

Nasal T-cell lymphomas represent a controversial subset of malignant lymphomas and include lesions previously termed midline malignant reticulosis, lymphomatoid granulomatosis, and polymorphic reticulosis. Nasal T-cell lymphomas are rare in Western populations and much more prevalent in Asian countries. Clinically, adult males are most often affected. Histologically, an angiocentric infiltrate composed of a spectrum of atypical cells is usually present. Phenotypically, the neoplastic cells lack expression of B-lineage markers, and usually express the T-lineage-associated markers CD2, CD45RO, and CD43; however, they often lack other pan-T-lineage markers. They often express the natural killer marker CD56, but usually lack the natural killer markers CD16 and CD57. Gene rearrangement studies have shown a germline configuration for the antigen receptor genes in the majority of cases. To date, evidence of Epstein-Barr virus has been consistently demonstrated, regardless of the geographic region studied. In situ hybridization studies have localized the Epstein-Barr virus to the atypical cells.

Angiocentric immunoproliferative lesion/T-cell non-Hodgkin's lymphoma and the acquired immune deficiency syndrome: A case report and review of the literature

The lesions known as lymphocytic vasculitis, polymorphic reticulosis (midline malignant reticulosis, lethal midline granuloma), lymphomatoid granulomatosis, and angiocentric lymphoma form what have been collectively termed the angiocentric immunoproliferative lesions (AIL). Because of recent reports demonstrating clonal rearrangements of the T-cell receptor in these lesions, the AIL are now thought to represent a continuous spectrum of post-thymic T-cell non-Hodgkin's lymphoma (NHL). NHL associated with the acquired immune deficiency syndrome (AIDS) represents intermediate or high-grade B-cell malignancies in HIV-infected patients that may be etiologically related to the Epstein-Barr virus (EBV). There have been reports of EBV-associated T-cell NHL, AIL, and large granular lymphocyte (LGL) proliferations, as well as HIV-associated T-cell neoplasia, LGL/T-cell proliferations, and AIL. We describe a case of polymorphic reticulosis (lethal midline granuloma) arising in an HIV-infected individual, who later progressed to AIDS, and review the literature on HIV-associated and EBV-associated T-cell neoplasia, LGL/T-cell proliferations, and AIL. The etiology of this AIL/T-cell NHL, especially in relation to EBV and HIV, is discussed.

Clinical evaluation four cases of malignant reticulosis

Clinical evaluation four cases of malignant reticulosis

悪性組織球症およびその類縁疾患の臨床病理

Clinicopathologic findings of 3 cases of malignant histiocytosis (MH), 8 cases of histiocytic medullary reticulosis (HMR), a case of familial hemophagocytic reticulosis (FHR), 8 cases of lymphoproliferative disorders terminating in HMR-like features (symptomatic HMR) and allied disorders are examined. Although it is problem whether MH is identical with HMR, there are some cases overlapping with each other. Pathologically, HMR has a broad spectrum condition containing etiology unknown, reactive, cataplastic, and neoplastic histiocytosis. Symptomatic HMR, especially the case of mosquitoe allergy is a very important on considering the pathogenesis of HMR. Because, as a result of prolonged mosquitoe allergy, immunodifficiency and abnormal T cell proliferation presented and eventually HMR-like feature progressed. It would consider that FHR is a special case of lymphoproliferative disorders rather than true histiocytosis. So called leukemic reticulosis or malignant reticulosis in Japan were heterogenous disorder including not only histiocytosis, but also T-cell, B-cell malignancy and monocytic leukemia.

Retrovirus-induced malignant histiocytosis in mice: a model for the human disease.

Malignant histiocytosis, also known as his-tiocytic medullary reticulosis or malignant reticulosis, is a hematopoietic neoplastic disorder characterized by proliferation of abnormal histiocytes and of their precursors, with mostly a rapidly fatal course [1, 2]. Clinical findings are fever, jaundice, pancy-topenia, and enlargement of liver, spleen, and lymph nodes. The etiology of the disease is unknown, although viral infections have been suggested as playing a role [3]. The study of its pathogenesis has been hampered by the lack of a suitable animal model. However, we have recently described a novel retrovirus inducing a systemic neoplastic disease in mice which is strikingly reminiscent of malignant histiocytosis in humans [4].

A-Heavy-Chain Disease With Erythematous Skin Lesions

To the Editor.— Since 1968, a large number of cases of α-heavy-chain disease (α-HCD) have been noted. The clinical signs of α-HCD are chronic diarrhea, severe malabsorption syndrome, steatorrhea of the gastrointestinal tract, and chronic bronchitis. The only other accompanying skin lesion, other than those mentioned above, described in the literature is clubbed finger nails. However, we have recently followed a unique case of α-HCD in which the patient had cutaneous lesions, lymphadenopathy, and hepatosplenomegaly. Report of a Case.— A 69-year-old man who presented with numerous infiltrated erythematous maculas on his face, back, and chest was hospitalized at Kinki University Hospital, Osaka, Japan, with a diagnosis of malignant reticulosis in June 1978. He showed neither dyspnea nor diarrhea. On physical examination, he was found to have 0.5- to 1.0-cm erythematous plaques involving his chest (Fig 1) and back, and 0.2- to 0.3-cm solid erythematous papules on his face