Chemotherapy of malignant histiocytosis in adults

Malignant Histiocytosis: A Clinicopathologic Study of 18 Consecutive Cases

The clinical records and histologic material of 18 consecutive patients with malignant histiocytosis were reviewed. The age of the patients ranged from 20 months to 72 years (median 35 years). There were 14 males and 4 females (3.5:1). Lymph node and liver enlargement, fever, and skin nodules were the most common physical findings; and leukocytosis was frequently the most abnormal laboratory test. Seven of 18 patients died, and their survival ranged from 1 to 15 months (median 8 months) after histopathologic diagnosis. The histologic findings on lymph nodes, spleen, liver, bone marrow, and skin were investigated with special reference to both the cellular composition and the pattern of lymph node involvement. Vascular invasion of small perinodal vessels was observed in 4 fatal cases. The absence of capsular invasion and the lack of cohesiveness among atypical proliferating histiocytes of malignant histiocytosis appeared to be inconstant. Sequential lymph node biopsies revealed in later stages the extension of the histiocytic proliferation from the sinuses into the cords and the complete obliteration of the nodal structures. The radiologic investigations yielded numerous pathologic findings that were consistent with the dissemination of the disease. Complete response to initial treatment was achieved in patients that were treated with radiotherapy and/or chemotherapy. Complete response with chemotherapy was achieved only when the treatment included adriamycin. The histologic and clinical features of the present series provide further evidence for the recognition of malignant histiocytosis as a distinct clinical and pathologic entity.

Lymphopenia in histiocytic medullary reticulosis

A survey of the Western literature of histiocytic medullary reticulosis (malignant histiocytosis) provided 104 case reports with sufficient data from which the presence or absence of an absolute lymphopenia could be ascertained. Of these, 46 (44%) were lymphopenic at presentation or within the subsequent 10 days. A survey of a series of publications containing detailed peripheral leucocyte counts recorded in patients with diseases that, like HMR, may present with, or develop, pancytopenia showed that the incidence of lymphopenia ranged from 14% (Hodgkin's: stages I & II) to 46% (acute myelofibrosis; systemic lupus erythematosus; angio-immunoblastic lymphadenopathy). It was concluded a that HMR should be added to the list of accepted causes of lymphopenia, b that lymphopenia, as an aid to the diagnosis of HMR, will be of limited value, c that when the peripheral leucocyte count of a patient is recorded in a case report, it should be accompanied by a full differential count.

Childhood anaplastic large cell lymphoma Ki-1/CD30: clinicopathologic features of 19 cases

The authors report their cumulative experience of 19 children with what was previously called malignant histiocytosis (MH) but is now considered a true lymphoma and termed anaplastic large cell lymphoma (ALCL). The median age at diagnosis was 10 years and 6 months (range 2 y, 11 m, to 15 y). There were 13 males and 6 females. Most cases presented with fever, wasting and enlarged, often tender, lymph nodes. Other features were: fleeting cutaneous rashes in 7 cases; spontaneous regression of lymph nodes and skin lesions were seen in 5 patients. Bone marrow involvement was present in 3 cases, pulmonary infiltrate in 5, kidneys in 2, and central nervous system in none. The morphology of lymph node involvement was consistent with so-called MH, a description originally applied to sinusoïdal infiltration by large "histiocytic" cells. The coexpression of lymphoid activation antigens Ki-1/CD 30 (18/19), epithelial membrane antigen EMA (18/19) and interleukin-2 receptor/CD 25 (10/10) was the unifying immunopathologic feature of the neoplasm. Lineage antigens were not identifiable in 8/19 instances (null phenotype), while 10/19 expressed a T-cell phenotype. None of the tumors expressed histiocytic markers. After variable, but intensive, combination chemotherapy, 15 children out of 18 evaluable achieved complete remission (CR). Among all patients, thirteen are still alive in CR (ten in first CR) with a median follow-up of 5 years. This evaluation in the pediatric age group reinforces that so-called MH is a lymphoid neoplasm, a conceptual change that could lead to improved understanding and therapy.

Unusual clinical presentation of malignant histiocytosis in a 70-year-old woman

A 70-year-old woman was admitted for evaluation of hepatosplenomegaly, fever and elevated serum LDH levels. A biopsy specimen of the liver revealed histiocytic proliferation at the portal triad, and a mild degree of hepatitis. A bone marrow biopsy specimen showed proliferation of histiocytes with minimal immaturity and atypism, and haemophagocytosis by the proliferated histiocytes. Fever, hepatosplenomegaly and elevation of LDH levels all disappeared spontaneously, and presumptive diagnosis of benign reticulosis with haemophagocytosis was made. One year later, fever, hepatosplenomegaly and elevation of LDH levels redeveloped, and the liver and bone marrow biopsy specimen showed proliferation of unequivocally malignant histiocytes. The patient died as a result of disseminated intravascular coagulation with shock 20 d later. We concluded that, in this case, malignant histiocytosis first presented as benign haemophagocytic reticulosis and, 1 year later, there was a typical malignant presentation.

Clinicopathological diagnosis and treatment of malignant histiocytosis

The diagnostic findings of malignant histiocytosis (MH) were analysed in 12 consecutive patients in a single institution. Most patients presented with systemic symptoms and lymphadenopathy (92%), splenomegaly (100%) and hepatomegaly (67%). Neurologic symptoms were present in three patients, while involvement of other organs was present in five patients. The incidence of severe thrombocytopenia was 92% of anaemia 92% and of leucocytopenia 67%. Serum angiotensin converting enzyme, alpha 1-antitrypsin and lysozyme were independently increased in 6/9, 3/10 and 1/9 patients respectively. High serum levels of tumour necrosis factor (TNF) were present in 3/10 patients, while serum levels of interleukin-1 were normal in 10/10 patients. Histologic evidence of MH was obtained in all patients by repeated biopsies of involved tissues. Four patients died prior to treatment. Seven patients were treated with combination chemotherapy, consisting of CHOP (cyclophosphamide, doxorubicin, vincristine, prednisone) or MOPP (chloromethine, vincristine, procarbazine, prednisone), in some cases followed by non-cross-resistant second line chemotherapy, if no complete response was attained. The response rate of treated patients was 57%, and progression was observed in two patients. The median duration of response was 38 months. Three patients are alive without evidence of disease and off therapy (30+, 83+, 85+ months). Although MH is a potentially lethal disease, combination chemotherapy may offer a chance for cure in some patients.

Malignant histiocytosis: therapeutic results in 27 children treated with a single polychemotherapy regimen

Twenty-seven children with histologically proven malignant histiocytosis were treated in the same institution from January, 1975 to December, 1986 with a combination chemotherapy regimen containing vincristine, cyclophosphamide, doxorubicine, and prednisone. Twenty-two patients achieved complete remission, one partial remission, and four no remission. Eight patients relapsed and were treated with Lomustine (CCNU), vinblastine, and bleomycin. In seven cases, a second complete remission was obtained. The overall survival rate is 81% at 5 years and the relapse-free survival rate is 54.5% at 5 years. Prognostic factors were fever and age under 10 at diagnosis, which were correlated with a higher incidence of relapse or no remission.

Malignant histiocytosis. Complete remission in two pediatric patients

The experience with the treatment of malignant histiocytosis has been disappointing. Despite modest treatment success with a combination of cyclophosphamide, Adriamycin (doxorubicin), vincristine and prednisone, the overall prognosis remains poor. There are only a few reports of prolonged complete remissions in pediatric patients. The following report describes two children who have had long-term remission with an aggressive combination chemotherapy program that included intrathecal prophylaxis. The chemotherapeutic regimen described merits further evaluation in a larger number of patients.

Reactive histiocytosis in acute lymphoblastic leukemia and non-Hodgkin's lymphoma

An extensive hemophagocytic syndrome in the termination of one case of pre-T acute lymphoblastic leukemia (ALL) and another case of non-Hodgkin's lymphoma (NHL), are described. Since most of the proliferating cells were mature macrophages and these cells were limited in the mononuclear phagocytic system (MPS), it was determined to be a reactive histiocytosis rather than histiocytic medullary reticulosis (HMR) or malignant histiocytosis (MH). The pathogenesis of the HMR or MH-like syndrome in these patients is discussed, and it is considered that this might be a reaction of the bacterial sepsis related to their immunosuppressed state secondary to the pre-existing malignancies and/or the cytotoxic therapy. The literature was reviewed. Based on a proposal for differential diagnosis between reactive histiocytosis and MH (or HMR), the heterogeneity of HMR-like syndrome complicating the malignancies are clarified.

Sinus histiocytosis with massive cervical lymphadenopathy. Case report and literature review

Sinus histiocytosis with massive cervical lymphadenopathy (SHML) was originally described in 1969 as a benign clinicopathologic entity characterized by massive bilateral cervical lymphadenopathy, fever, leukocytosis, elevated ESR, and hypergammaglobulinemia, usually occurring within the first two decades of life. We present an illustrated case of an elderly patient with polyclonal hypergammaglobulinemia and a 2-year history of multilobulated cervical and submandibular lymphadenopathy. The etiology and pathogenesis of SHML are not known. Diagnosis requires lymph node biopsy to exclude other causes of cervical lymphadenopathy such as malignant lymphoma, malignant histiocytosis, metastatic carcinoma, and tuberculous lymphadenitis. Histologic examination shows marked dilatation of subcapsular and medullary lymph node sinuses containing large, foamy or vacuolated histiocytes. Although no curative treatment is known, corticosteroids, radiation therapy, vinblastine and oral cyclophosphamide, and surgery have been used to palliate constitutional symptoms and mechanical obstruction from massive lymphadenopathy. Since one third of SHML patients have evidence of disease for 5 years, and a mortality rate of 7% exists with benign histologic disease, all patients with SHML should be carefully screened for evidence of immunodeficiencies that may precipitate a fatal outcome.

Acute myeloid leukaemia in childhood: clinical features and prognosis

Clinical and laboratory features at presentation were correlated with morphological (FAB) subclass of AML in a group of 112 children diagnosed between 1972 and 1982. Patients with a monocytic component of AML (M4, M5) had higher initial leucocyte counts, a higher incidence of extramedullary infiltration and of CNS involvement. In M4 AML CNS relapse occurred in patients with a high initial leucocyte count whereas in M5 AML CNS involvement tended to occur at presentation in children with low initial counts. Two-thirds of patients treated achieved remission and most failures were due to inadequate chemotherapy, although haemorrhage, leucostasis or metabolic complications caused early death in patients with M4 and M5 AML. With a minimum follow up of 3 years only 12% of patients are alive; these figures have not improved in consecutive series despite increasing intensity of induction and more recent availability of bone marrow transplantation. No features predictive of long-term survival were identified, but patients with myeloid differentiation (M1, M2, M3) did better than those with a monocytic or erythroid component (M4, M5, M6). The proportion of patients with AML curable by chemotherapy seems unlikely to increase without marked intensification of post-remission chemotherapy. More aggressive CNS prophylaxis may be of benefit in cases with a monocytic component.

Malignant histiocytoses developing in patients with B-cell lymphomas. Report of two cases

Two patients with indolent B-cell lymphomas (small B-cell and small cleaved cell) developed a coexistent malignant histiocytosis 3 and 6 years after diagnosis of their lymphomas. In both patients, malignant histiocytosis presented as new onset of fever, weight loss, and rapidly progressive bulky disease super-imposed on a previously stable clinical course without constitutional symptoms. Both patients failed to respond to combination chemotherapy. The terminal aggressive phase of indolent B-cell lymphomas usually represents transformation of the original neoplasm to a large non-cleaved or immunoblastic B-cell histology. Malignant histiocytosis has not previously been reported as a second neoplasm in patients with B-cell lymphomas.

Bone marrow transplantation for malignant histiocytosis in childhood

This report describes a girl who was diagnosed with malignant histiocytosis at the age of 5 years. The disease was controlled initially with chemotherapy for 3 years and had then recurred with meningeal involvement on three occasions. Four years and 8 months from diagnosis, bone marrow transplantation (BMT) was undertaken from an HLA-identical and mixed lymphocyte culture (MLC) nonreactive brother after conditioning with VP-16-213 5 mg/kg/day X 2, cyclophosphamide 60 mg/kg/day X 2, and total body irradiation 200 rad twice daily to a total dose of 1000 rad delivered at 7 rad/minute. At the time of transplant, the disease was in remission. Currently, more than 48 months after the transplant, the child remains free of disease, with a normally functioning donor marrow and with no evidence of graft versus host disease. This is the first recorded case of BMT in the treatment of malignant histiocytosis. The outcome in this patient in late-stage disease suggests that BMT could be considered early in management as definitive therapy.

Cytophagic histiocytic panniculitis. A variant of malignant histiocytosis

This report describes a patient with cytophagic histiocytic panniculitis in which the aggressive use of chemotherapeutic agents resulted in an apparent remission. The histiocytic nature of the process was confirmed by immunohistochemical techniques. There are many similarities with malignant histiocytosis, and it is believed that this entity should be regarded as a variant of malignant histiocytosis.

Malignant histiocytosis. Report of twenty-five cases with pulmonary, renal and/or gastro-intestinal involvement

Recent papers have shown that malignant histiocytosis (MH) can be well controlled if the disease is diagnosed early and treated intensely. Previous reports proposed the usefulness of lymph nodes and liver biopsy or bone marrow aspiration in making a diagnosis of MH, but even when a combination of these three procedures was used, between 24 and 61% of patients with MH could not be correctly diagnosed. In the present study, clinical and autopsy findings in 25 patients with MH were reviewed to identify possible alternative diagnostic sites to lymph nodes, liver or bone marrow. Clinical symptoms were observed in the respiratory (40%) and gastro-intestinal (48%) tracts. Proteinuria was also frequently identified (60%). Autopsy findings showed that involvement of lung, stomach and small intestine, and kidney by atypical histiocytes were present in 100% of patients with respiratory symptoms, 85% of those with abdominal symptoms and 80% of those with proteinuria, respectively. From the analysis of this pattern of histiocytic infiltration, lung, renal, gastric or jejunal biopsies are demonstrated as sites for the diagnosis of MH.

Familial erythrophagocytic reticulosis. Complete response to combination chemotherapy

Two infants with familial erythrophagocytic reticulosis attained a durable complete remission after combination chemotherapy including intrathecal methotrexate. Though both later died, neither child had definitive evidence of tumour at necropsy.

Sjögren syndrome and lupus erythematosus nephritis

A 9 year old girl with symptoms of the Sjögren syndrome showed interstitial lymphocytic infiltrate on renal biopsy. Two years later she had clinical and biological evidence of systemic lupus erythematosus, associated with a typical glomerulonephritis.

Malignant histiocytosis

The clinical features, therapy, and hospital course of ten consecutive patients with malignant histiocytosis (MH) are presented. The value of bone marrow aspiration for the diagnosis is discussed. The patient's performance status as described in this report by the organ dysfunction score may predict survival and response to chemotherapy. The literature on chemotherapy in this disease is reviewed. Combination chemotherapy may be the best approach to treatment, but there is little experience with single agents. There is a great need for better characterization of the malignant cell in this disorder.

Histiomonocytic malignancy. A spectrum of disease in an 11-month-old infant

The initial pathologic diagnosis in an 11-month-old girl presenting with a suprarenal mass was true histiocytic lymphoma. The histiocytic nature of the cells was verified by ultrastructural, histochemical, and immunologic studies. The subsequent course featured widespread dissemination as both tumorous masses and diffuse tissue infiltrates, including extensive soft tissue, leptomeningeal, and bone marrow involvement, with a terminal histiomonocytic leukemic phase. Subsequently, this tumor was reclassified as malignant histiocytosis with atypical features, and this case exemplifies the difficulties in classifying some malignant histiomonocytic neoplasms. The overlapping clinical, pathologic, and theoretic features of true histiocytic lymphoma, malignant histiocytosis, and histiomonocytic leukemia are discussed in the context of this case.

Malignant histiocytosis. Clinical and cytogenetic studies in a newborn and a child

Malignant histiocytosis (MH) was diagnosed on the cytologic and cytochemical features of the malignant cells present in bone marrow smears from an infant and a child. The diagnosis of MH was confirmed by light and electron microscopic studies on bone marrow and skin biopsy specimens, and bone marrow and liver biopsy specimens, respectively. Both patients showed a deterioration while receiving prednisone monotherapy, but they responded well to a combination of vincristine and cyclophosphamide. The infant has remained disease-free for 52+ months now, but the child died of a relapse 11 months after diagnosis. Cytogenetic studies of blood and/or bone marrow cells were performed before treatment. In the infant, a pathologic cell line with a translocation t(8;16)(p11;p13) was found; this abnormality was no longer present after remission was obtained. In the second patient, a hyperdiploid cell line with major karyotypic anomalies was found. When studied in relapse and shortly before death, additional chromosomal abnormalities were seen. The data from this study show that prednisone should be used with caution in MH, and that it should be omitted from combination chemotherapy when adverse effects are noted during short-term monotherapy. Also, cytogenetic studies should be performed more often in MH to determine the significance and possible nonrandomness of chromosomal abnormalities in this disease.

Intravascular malignant histiocytosis mimicking central nervous system vasculitis: an immunopathological diagnostic approach

A 53-year-old man presented with a lumbosacral polyradiculoneuropathy and developed fluctuating encephalopathy suggestive of multifocal small vessel disease. Postmortem examination demonstrated multifocal vascular occlusion by undifferentiated cells confined to the intravascular space. Extravascular spread was found only in spleen and liver. The presence of lysozyme and absence of factor VIII in the cytoplasm of the malignant cells confirmed their histiocytic nature. This patient had an unusual intravascular form of malignant histiocytosis that must be included in the differential diagnosis of multifocal vascular disease.

Sinusoidal large cell ("histiocytic") lymphoma

A sinusoidal pattern of involvement by large cell ("histiocytic") lymphoma was present focally or throughout the initial lymph node biopsies of 18 patients. Clinical, ultrastructural, histochemical, and immunopathologic studies confirm that this is lymphoma. The recognition of this variant of large cell lymphoma is important in avoiding the common misdiagnoses, which were metastatic carcinoma, metastatic malignant melanoma, and malignant histiocytosis. The number of patients is too small for comment on whether the pattern has prognostic implications.

Malignant histiocytosis in childhood: clinical study and therapeutic results in 22 cases

Twenty-two children with malignant histiocytosis ranging in age from 2 to 13 1/2 years are described. In 10 cases, the correct diagnosis was only made retrospectively. The most salient pathologic features were found in lymph node biopsy specimens. Fever and wasting were the most prominent symptoms in 21 cases, and abdominal pains were striking in 9. Peripheral lymphadenopathy, mostly of the cervicoaxillary type, was present in 21 patients, with marked tenderness in 14. Abnormal mediastinal and/or paraaortic lymph nodes were detected radiographically in two-thirds of the patients. Other prominent features included subcutaneous inflammatory infiltration in 12 patients and skin nodules in 8. Pleural effusions were seen in 8 children. The haematologic findings are described. Only 5 of 19 children had bonemarrow involvement. Fifteen patients died, one to 45 months from onset of their illness (median survival time, five months). Nine patients are alive with no evidence of disease 21 to 46+ months (median, 40 months) after the time of diagnosis and 8 have currently been off treatment for periods ranging from three to 29 months; they all have been treated with vincristine, prednisone, cyclophosphamide, and adriamycin and 4 have achieved remission after treatment with vinblastine, bleomycin, and CCNU or cytosine-arabinoside. It is concluded from this study that clearly delineated clinical features of malignant histiocytosis in childhood should allow more rapid determination of the proper diagnosis and should result in early treatment by means of intensive systemic combination chemotherapy, which has dramatically improved the prognosis.

Malignant histiocytosis. Clinical findings and therapy

Diagnosis of malignant histiocytosis (MH) was confirmed in 16 patients. Stage at diagnosis was I-II in nine, and III-IV in seven patients. Porr prognosis and "B",-symptoms were correlated to advanced stages. Bone marrow biopsy proved most useful to verify organ involvement. Scintigraphy and computerized tomography, too, detected organ involvement in some patients and were helpful for judging response to therapy. Relapses after radiotherapy were frequent. Polychemotherapy using "CHOP"-combination is recommended for most patients and may in stages I-II be supplemented by primary or secondary involved or extended field irradiation and in more advanced stages by mainbulk-irradiation. The value of prophylactic CNS-therapy remains controversial. Pathophysiological aspects and differential diagnosis are discussed.

Adriamycin and splenectomy in the treatment of histiocytic medullary reticulosis

Histiocytic medullary reticulosis (HMR) is a rare, malignant disorder with unsatisfactory response to various chemotherapeutic agents that have been used up to the present time. The purpose of this communication is to describe the first patient with this disease in whom an immediate, complete remission was obtained using only adriamycin. Four months after institution of this treatment, a staging laparotomy and splenectomy revealed residual disease in the spleen only. Adriamycin was continued as the sole agent, to the full calculated dose, followed by maintenance therapy consisting of cyclophosphamide. The patient continues to be in complete remission 35 months after diagnosis was established.

Malignant histiocytosis in adults: report of 7 patients from Northeast Italy

The clinical records and histologic material of seven adult male patients with malignant histiocytosis (MH), observed consecutively at our center during a four-year period, have been reviewed; four of these cases were seen in a year. All patients were born and lived within a radius of 30 miles from Pordenone, a town in northeast Italy. The diagnosis of MH was made in all cases on lymph node biopsy on the basis of the established histologic criteria [1]. At presentation, abnormal histiomonocytic cells were found in the bone marrow and peripheral blood of four patients, two of whom also showed cerebrospinal fluid involvement with atypical histiocytes at a relatively early stage of the disease. Staging procedures documented extensive disease in lymphatic, as well as in extralymphatic, sites in four patients; in three patients, the disease was confined to the lymphatic system. Combination chemotherapy was the first treatment employed in all cases. Four patients, three of whom had limited disease, achieved complete remission with quadruple combination chemotherapy (ABVD, CHOP, or MOPP); three patients with extensive disease achieved only partial remission of short duration with HOP. These results further support the view that adult MH is not obligatorily and rapidly fatal. Good responses to treatment with combination chemotherapy are possible, particularly in patients with disease limited to only lymphatic sites.

Malignant histiocytosis. Immunohistochemical characterization on paraffin embedded tissue

Clinically, malignant histiocytosis is a malignant neoplasia with poor prognosis. Diseased are lymphnodes (especially cervical nodes), liver, spleen and bones. Few cases become leukemic. The cells show characteristic pale roundish, often indented nuclei, without large nucleoli and with abundant ill-defined cytoplasm. Phagocytosis of erythrocytes and leukocytes, as well as, hemosiderin deposits may serve as indicators for histiocytic, respectively macrophagic qualities. On touch preparation, tumor cells previously had been marked by acid phosphatase and non-spevific esterase, as being histiocytic. - A comparable marking could be carried out on paraffin embedded material with lysozyme (muramidase) and alpha1-antichymotrypsin, by the indirect immuno-peroxidase technique. No correlation could be proven between any special shape of tumor cells or between different grades of cellular atypism and presence or absence of the immunohistochemical reaction. The reaction with lysozyme and alpha1-antichymotrypsin was also tested in other tumors and was found to be positive in a variety of different tumor cells showing degenerative changes, respectively necrobiosis. - But lysozyme and alpha1-antichymotrypsin are markers characteristically found in histiocytes, respectively histiocytic tumor cells. They are apparently less distinct in MH with a larger number of immature histiocytic tumor cells.

Non-Hodgkin's lymphoma and acute myeloblastic leukemia: a report of 12 cases and review of the literature

Twelve cases of non-Hodgkin's lymphoma and acute myeloblastic leukemia or one of its variants are reported. An additional 33 cases from the literature are reviewed. The mean interval between the diagnosis of lymphoma and acute leukemia is 5.2 years. In 5 patients the two diseases occurred simultaneously or within 6 months of each other. All but 10 of the 45 patients received radiation therapy for their lymphoma. Nine patients had either total nodal or total body irradiation or both. Eight patients received chemotherapy alone. No patient was untreated. Survival after the diagnosis of acute leukemia ranged from 3 days to 14 months, with a median of 3 months. Four patients achieved complete hematological remission following antileukemic therapy. Acute leukemia is estimated to occur in patients with non-Hodgkin's lymphoma in New York State with a 37-fold increased frequency over the expected number. Although acute leukemia may occur in a higher than expected frequency in patients with non-Hodgkin's lymphoma because of an increased risk of a second neoplasm in patients with a primary tumor, it seems more likely that the acute leukemia may be related to the radiotherapy and/or chemotherapy administered to treat the lymphoma. Late death from leukemia after chemotherapeutic or radiotherapeutic remission of advanced non-Hodgkin's lymphoma is preferable to morbidity and/or early death from untreated or inadequately treated lymphoma.

Sarcomatous variant of malignant histiocytosis; a case report and review of the literature

The case is that of a 21-year-old female with mediastinal and subcutaneous, tumors composed of sarcomatous growth of poorly differentiated histiocytes defined by enzyme histochemical staining, ultrastructural observation and detection of surface markers. At autopsy neoplastic cells in the solid tumor became less cohesive and pleomorphic with erythrophagia, while features in the lymph node draining from the tumor was compatible with the criteria of malignant histiocytosis. The place where such a sarcomatous variant of malignant histiocytosis should be placed within other histiocytic tumors is discussed and the literature reviewed.

Malignant histiocytosis: report of five Chinese patients

Five Chinese patients with malignant histiocytosis are described, the diagnosis being based on microscopic evidence of infiltration of at least three different tissues by noncohesive atypical phagocytic histiocytes, without total obliteration of normal architecture of those tissues. The mean age of the patients was 28 years; all presented with pyrexia (of 2 weeks to 2 1/2 years duration) and all had circulating neoplastic cells. Two patients showed remission with quadruple chemotherapy and one is alive and without symptoms 6 years after onset of his illness.

Malignant histiocytosis: a clinico-pathological study of 12 cases

The clinico-pathological features of 12 cases of malignant histiocytosis (histiocytic medullary reticulosis), aged 12-60 years, were studied. Special emphasis was put on the analysis of the haematological, cytological and histopathological findings of the disease. Bone marrow aspirates and biopsies from involved tissues (liver, lymph node, spleen and skin) were found best suited for establishing the diagnosis. Cytochemical and ultrastructural data support the concept that the neoplastic cells belong to the mononuclear-phagocyte system. Three untreated patients died in less than 6 months. Median survival of the nine treated patients was 1 year. Seven patients were treated with the combination chemotherapy CHOP and four achieved a complete remission. Three of them are alive and continue in unmaintained remission for more than 1 year, surviving so far for 18+ to 31+ months. Two cases showed evidence of CNS involvement, one during life and the other as a post-mortem finding. The differential diagnosis from other related or unrelated disorders and the possible aetiological factors responsible for the disease are discussed in detail.

Malignant histiocytosis. Histiocytic medullary reticulosis

Three cases of malignant histiocytosis occurring in children aged 2 months, 10 months and 14 years, are described. In all children the diagnosis was based on anaemia, granulocytopenia or thrombocytopenia, splenomegaly and marked erythrophagocytosis by bone marrow and lymph node atypical histiocytes. Two children aged 10 months and 14 years, underwent splenectomy after which combined chemotherapy with cyclophosphamide, vincristine and prednisone (COP) was started. In the older child a complete remission was achieved. The younger child died soon after the onset of the treatment. The youngest child was treated with bleomycin, adriamycin, cyclophosphamide, vincristine and prednisone (BACOP). He died of pneumonia and sepsis two months after the start of the treatment.

Effective combination chemotherapy of adult malignant histiocytosis (histiocytic medullary reticulosis)

Adult malignant histiocytosis, also known as histiocytic medullary reticulosis, has been, in the past, considered a very aggressive disorder usually resistant to chemotherapy. Management in the past has included either single agent therapy or splenectomy. Recently, several cases have been reported that have responded favorably to combination chemotherapy. This paper reports on our experience with combination chemotherapy for this disorder. Of three patients treated, all three responded with a complete remission and two remain alive and free of disease at the present time. The outlook for patients with this diagnosis appears to be changing favorably with the advent of new treatment regimens.