Malignant histiocytosis. A reassessment of cases previously reported in 1975 based on paraffin section immunophenotyping studies

NF1 mutation and TUBB3 amplification in gastric histiocytic sarcoma: a case report and literature review

Histiocytic sarcoma is a rare neoplasm of mature histiocytes with an aggressive clinical course and poor response to treatment. Primary gastric histiocytic sarcoma is rarer and just reported sporadically.Histiocytic sarcoma is a rare neoplasm of mature histiocytes with an aggressive clinical course and poor response to treatment. Primary gastric histiocytic sarcoma is rarer and just reported sporadically. A case of a 71-year-old female admitted with a one-year history of upper abdominal pain exacerbated after meals. After CT scans revealed a bulged mass at the lesser curvature of the gastric body, the patient underwent endoscopic submucosal dissection. Microscopically, non-cohesive neoplastic cells diffusely infiltrated lamina propria and submucosa, and diffusely expressed LCA, CD4, CD163, CD68 (KP1), Cyclin D1, Lysozyme, and Vimentin. PD-L1 (22CS) expression evaluated as CPS 60. The final pathological diagnosis was gastric histiocytic sarcoma. Subsequently, next-generation sequencing identified a nonsense mutation in exon 21 of NF1 gene [c.2446C > T (p.R816*)] and the TUBB3 gene amplification (copy number: 4.55). The patient refused further treatment and died of the tumor half a year later. This case broadens the spectrum of differential diagnosis of gastric cancer and emphasizes the value of immunohistochemical and molecular tests in the accurate diagnosis of histiocytic sarcoma. Furthermore, we performed literature review of 11 cases of gastric histiocytic sarcoma so as to strengthen the understanding of the clinicopathologic features, treatment, and prognosis.

The many faces of mouse histiocytic sarcoma in C57BL/6J mice

Histiocytic sarcoma is a tumor of the hematopoietic system considered to be derived from macrophages. Although rare in humans, it occurs frequently in mice. Histiocytic sarcoma can be a difficult tumor to diagnose due to its diverse cellular morphologies, growth patterns, and organ distributions. The varying morphology of histiocytic sarcomas makes it easy to confuse them with other types of neoplasia, including hepatic hemangiosarcoma, uterine schwannoma, leiomyosarcoma, uterine stromal cell tumor, intramedullary osteosarcoma, and myeloid leukemia. As such, immunohistochemistry (IHC) is often needed to differentiate histiocytic sarcomas from other common tumors in mice that they can morphologically mimic. The goal of this article is to present a broader perspective of the diverse cellular morphologies, growth patterns, organ distributions, and IHC labeling of histiocytic sarcomas encountered by the authors. This article describes these features in a set of 62 mouse histiocytic sarcomas, including the IHC characterization of the tumors using a panel of markers for the macrophage antigens F4/80, IBA1, MAC2, CD163, CD68, and lysozyme, and describes differentiating features of histiocytic sarcomas from other morphologically similar tumors. The genetic changes underlying the pathogenesis of histiocytic sarcoma in humans are beginning to be elucidated, but this is difficult due to its rarity. The higher prevalence of this tumor in mice provides opportunities to investigate mechanisms of its development and to test potential treatments.

Sudden Unexpected Death Caused by Cardiac Metastasization from Histiocytic Sarcoma

Background: Haematological malignancies, such as lymphoma and leukaemia, can have a variety of clinical manifestations. The most frequent cause of death from haematological malignancies is multiple organ failure due to neoplastic organ infiltration and/or septic shock. Histiocytic sarcoma (HS) is a rare malignant nodal or extranodal tumour with histiocytic immunophenotype that originates from a lymphohematopoietic precursor. The patients with HS usually have a poor prognosis due to its aggressive clinical behaviour. Rare cases of undiagnosed sudden HS death have been described in the literature. Methods: A forensic autopsy of a 46-year-old white male who died at home suddenly and unexpectedly without warning conditions or known diseases. Gross analysis, histology and toxicology were also performed. Results: The diagnosis of HS of the ileum with secondary nodal and cardiac metastatization was made. Conclusions: A prompt diagnosis of HS in life is paramount because it can make a difference in prognostic outcomes.

Spectrum of histiocytic neoplasms associated with diverse haematological malignancies bearing the same oncogenic mutation

Histiocytic disorders are a spectrum of rare diseases characterised by the accumulation of macrophage-, dendritic cell-, or monocyte-differentiated cells in various tissues and organs. The discovery of recurrent genetic alterations in many of these histiocytoses has led to their recognition as clonal neoplastic diseases. Moreover, the identification of the same somatic mutation in histiocytic lesions and peripheral blood and/or bone marrow cells from histiocytosis patients has provided evidence for systemic histiocytic neoplasms to originate from haematopoietic stem/progenitor cells (HSPCs). Here, we investigated associations between histiocytic disorders and additional haematological malignancies bearing the same genetic alteration(s) using the nationwide Dutch Pathology Registry. By searching on pathologist-assigned diagnostic terms for the various histiocytic disorders, we identified 4602 patients with a putative histopathological diagnosis of a histiocytic disorder between 1971 and 2019. Histiocytosis-affected tissue samples of 187 patients had been analysed for genetic alterations as part of routine molecular diagnostics, including from nine patients with an additional haematological malignancy. Among these patients, we discovered three cases with different histiocytic neoplasms and additional haematological malignancies bearing identical oncogenic mutations, including one patient with concomitant KRAS p.A59E mutated histiocytic sarcoma and chronic myelomonocytic leukaemia (CMML), one patient with synchronous NRAS p.G12V mutated indeterminate cell histiocytosis and CMML, and one patient with subsequent NRAS p.Q61R mutated Erdheim-Chester disease and acute myeloid leukaemia. These cases support the existence of a common haematopoietic cell-of-origin in at least a proportion of patients with a histiocytic neoplasm and additional haematological malignancy. In addition, they suggest that driver mutations in particular genes (e.g. N/KRAS) may specifically predispose to the development of an additional clonally related haematological malignancy or secondary histiocytic neoplasm. Finally, the putative existence of derailed multipotent HSPCs in these patients emphasises the importance of adequate (bone marrow) staging, molecular analysis and long-term follow-up of all histiocytosis patients.

Sudden unexpected death from an undiagnosed histiocytic sarcoma in an adolescent female

A previously well 15-year-old female who was awaiting medical investigations for a proptosed right eye collapsed and died suddenly while walking. Postmortem examination revealed diffuse distortion and infiltration of multiple organs by a suspected neoplastic process. Histology confirmed the invasion of multiple organs by atypical cells and myocardial infiltration was the likely cause of death. An extensive panel of immunohistochemistry established the diagnosis of a histiocytic sarcoma. Sudden unexpected death due to a clinically undiagnosed neoplasia in childhood and adolescence is uncommon. This is the first report of a histiocytic sarcoma causing sudden unexpected death and highlights the importance of considering undiagnosed hematological malignancies when examining a case of sudden death at postmortem.

Successful Treatment of Multifocal Histiocytic Sarcoma Occurring after Renal Transplantation with Cladribine, High-Dose Cytarabine, G-CSF, and Mitoxantrone (CLAG-M) Followed by Allogeneic Hematopoietic Stem Cell Transplantation

Histiocytic sarcoma (HS) is a rare, aggressive malignancy. Lesions previously called HS were typically non-Hodgkin lymphomas, not HS. As such, chemotherapy directed at lymphoid neoplasms was frequently successful, but it is unclear if these regimens are ideal for HS. We present a 33-year-old African gentleman who underwent sequential renal transplants for glomerulonephritis. He subsequently developed HS of the upper airway and multiple cutaneous sites. The patient received cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) followed by salvage ifosfamide, carboplatin, and etoposide (ICE) but had continuous progression of cutaneous involvement. Cladribine, high-dose cytarabine, G-CSF, and mitoxantrone (CLAG-M) yielded a partial response with near resolution of disease. Ultimately, the patient achieved a complete remission after myeloablative allogeneic hematopoietic stem cell transplant. HS occurring after solid organ transplant raises the possibility of HS as a potential posttransplant malignancy. The use of CLAG-M has not been reported in HS. In this case, histiocyte-directed chemotherapy with CLAG-M was superior to lymphoma-directed regimens.

Radiotherapy for histiocytic sarcoma: a case report

Background

Histiocystic sarcoma is a rare, but aggressive tumour that often involves extranodal sites. Histiocystic sarcoma is recognised by the World Health Organization as one of six subtypes of dendritic cell neoplasms. Diagnosis is difficult due to overlapping immunohistochemistry with other dendritic cell neoplasms. The optimal roles for chemotherapy, radiotherapy and surgery in the treatment of histiocytic sarcoma remain unknown.

Methods

We report a case of a patient with histiocytic sarcoma diagnosed after excisional biopsy and immunohistochemistry testing.

Results

The patient underwent external beam radiation therapy (EBRT). After 18 Gray (Gy), the 8 cm lesion had regressed to ~5 cm in diameter. The treatments were continued to a total dose of 45 Gy with the lesion regressing to less than a centimeter by the end of treatment. Local control was maintained but the patient died of acute myelogenous leukemia 5 months after her treatment.

Conclusions

This case suggests that histicytic sarcomas can be controlled locally with EBRT.

Primary hepatic and hepatosplenic diffuse large B-cell lymphomas with intrasinusoidal and interstitial lymphomatous infiltration

Primary hepatic and hepatosplenic diffuse large B-cell lymphomas (DLBCLs) are rare cancers and form nodules in most instances. However, very rare cases can diffusely infiltrate the whole liver without nodules. The general clinicopathological features of these lymphomas have not been reported to date. In our current study, we attempted to elucidate the features of these lesions through our direct observations and by reviewing the current literature. We describe the characteristics of 2 patients with hepatic and hepatosplenic DLBCL by autopsy. The lymphoma cells showed diffuse infiltration of the liver, red pulp of the spleen, and bone marrow with intrasinusoidal and interstitial lymphomatous infiltration of the organs. We discuss our observations in relation to previously reported DLBCLs with a similar pathology.

Histiocytic sarcoma of the brain

Histiocytic sarcoma is a rare malignant neoplasm of the lympho-hematopoietic system that usually occurs in the skin, lymph nodes and intestinal tract. We present a 36-year-old woman with a rare histiocytic sarcoma with isolated central nervous system (CNS) involvement of multifocal circumscribed lesions. Biopsy of the brain lesions showed diffuse proliferation of pleomorphic histiocytes that were immunopositive for CD45, CD68 and CD163. Various cytokeratins and markers of lymphoma, melanoma, germ cell tumours and primary CNS tumours were negative. Examination of bone marrow trephine and a whole-body positron emission tomography scan showed no evidence of involvement of any other organ systems, thus establishing the primary nature of the lesion. The neoplastic cells uniquely showed eosinophilic globules within the cytoplasm, which were positive for CD68. These globules were shown by electron microscopy to be collections of lysosomes. A thorough discussion of the differential diagnosis and literature review is included.

Cytogenetics findings in a histiocytic sarcoma case

Histiocytic sarcoma (HS) is a neoplasm derived from histiocytes. Its diagnosis was not clear until its immunohistochemistry profile was correctly established. Not much is known about its genetic properties. We report a case of a 48-year-old male patient whose bone marrow was almost completely occupied by monomorphic medium size neoplastic cellularity. Its immunohistochemical profile was CD68(+), CD4(+), CD45(+) with negativity of other dendritic cells, and other lineage markers. Cytogenetic study showed 4 related clones: one with trisomy 8 and extra material on the short arms of chromosome 4; a second line with tetrasomy of chromosome 8, add(4)(p16); the third clone had the same alterations as the previous and deletion of chromosome 3 at q11; the fourth line had tetrasomy 8 and translocation t(3;5)(q25;q35). To our knowledge this is the first HS case showing chromosome 8 trisomy and tetrasomy and the other described alterations.

High frequency of fatal haemophagocytic lymphohistiocytosis syndrome in enteropathy-associated T cell lymphoma

INTRODUCTION

Enteropathy-associated T-cell lymphoma is a rare form of T-cell lymphoma associated with a poor prognosis and the relative ineffectiveness of standard chemotherapy. The occurrence of haemophagocytic lymphohistiocytosis has been reported only once with this entity.

PATIENTS AND METHODS

A retrospective study of 15 patients with enteropathy-associated T-cell lymphoma (type 1 in 12), followed-up in our units, since 1985. Two patients died before starting chemotherapy. The remaining 13 patients were treated with standard chemotherapy (n=7) and purine nucleotide analogues (n=6).

RESULTS

Median follow-up was 8.7 (1-97) months. Surgery was required in 10 patients (66%) for intestinal complications (n=7) or elective small bowel resection (n=3). Survival probability was 40% and 20% at 1 and 5 years, respectively (Kaplan-Meier method). Survival was not significantly different between the two chemotherapy regimens. However, a slight decrease of febrile neutropenia was observed in the purine nucleotide analogues group (p=0.06). Haemophagocytic lymphohistiocytosis occurred in 6/15 (40%) cases. In these six patients, haemophagocytic lymphohistiocytosis was always fatal within 3 months.

CONCLUSION

Enteropathy-associated T-cell lymphoma is associated with a poor outcome, independently of the chemotherapy regimens administered and frequent occurrence of haemophagocytic lymphohistiocytosis. The latter complication should be considered for urgent rescue therapy.

Non-anaplastic peripheral t-cell lymphoma in childhood and adolescence: a Children's Oncology Group study

BACKGROUND

Peripheral T-cell lymphomas (PTCL) other than anaplastic large cell lymphoma (ALCL) are rare in young patients. While a high proportion of adults with PTCL have poor risk disease, pediatric PTCL is not well characterized. This study examines the outcome of localized and advanced PTCL in pediatric patients treated in standardized fashion.

PROCEDURE

We identified 20 pediatric patients diagnosed with PTCL whose tumor cells did not express CD30 and/or ALK, as determined by immunohistochemistry, between 1992 and 2000 on one of two treatment protocols for localized NHL (POG 9219) or advanced stage large cell lymphoma (POG 9315). All cases were centrally reviewed.

RESULTS

The median age was 12.6 (range 0.7-16.9)-9 male and 11 female. Histological subtypes in the WHO Classification included PTCL, unspecified (12), extra-nodal NK/T-cell lymphoma of nasal type (4), subcutaneous panniculitis-like T cell lymphoma (1) and enteropathy-type T-cell lymphoma (1). Two cases exhibited both T-cell and histiocyte markers and were reclassified as histiocytic sarcoma per the WHO, although T-lineage remains possible. Of 10 patients with localized disease, only two relapsed and 9 survive. Of 10 patients with advanced disease, six relapsed and five (50%) survive.

CONCLUSIONS

These results suggest that localized PTCL in children and adolescents is frequently cured with modern therapy, but that advanced stage cases may require novel therapy.

Histiocytic sarcoma: identification of its histiocytic origin using immunohistochemistry

We describe a 56-year-old woman with histiocytic sarcoma involving the bone marrow. The neoplastic cells proliferated diffusely and showed occasional erythrophagocytosis. Immunohistochemically, the neoplastic cells were positive for CD68, lysozyme, CD4 and CD163, but negative for B- and T-cell markers, S100 protein and epithelial markers. The patient received multi-agent chemotherapy and is living at 22 months after diagnosis without recurrence. Histiocytic sarcoma is an exceedingly rare hematopoietic neoplasm and the prognosis is poor due to its rapid progression, widespread disease and poor response to therapy. It is important to recognize this rare neoplasm and to confirm the diagnosis using specific immunohistochemical markers.

Cutaneous Langerhans cell sarcoma: a case report and review of the literature

Langerhans cell sarcoma (LCS) is a neoplastic proliferation of Langerhans cells that occurs in lymph nodes, liver, skin, spleen, lung, and bone. We report a case of LCS in a 47-year-old man with a 6-month history of scalp mass and cervical lymphadenopathy. Clinical and pathologic data were available. A histologic examination demonstrated a proliferation of cells with malignant cytologic features. Because of its poorly differentiated morphologic features, hematologic and nonhematologic entities were ruled out by immunohistochemical screening with a broad panel of antibodies. Ultrastructural studies demonstrating Birbeck granules and consistent expression of CD1a, S-100 protein, and langerin by immunohistochemistry were helpful in identifying the Langerhans cell origin.

Lymphoma-associated hemophagocytic syndrome: clinical features and treatment outcome

The clinical features and prognostic factor of lymphoma-associated hemophagocytic syndrome (LAHS), diagnosed according to World Health Organization classification, were investigated by reviewing the clinical records of 29 patients between September 1994 and September 2006. Compared with patients with T or natural killer (NK)/T cell LAHS, patients with B cell LAHS were older (p = 0.022), were less likely to exhibit disseminated intravascular coagulation (DIC; p = 0.011), and had less direct involvement of bone marrow (p = 0.03). Clinical response was achieved in 15 (65.2%) and complete remission (CR) was achieved in 4 (17%) of 23 patients who received chemotherapy. Four patients received high-dose chemotherapy and autologous stem cell transplantation (A-SCT), and three of these four patients showed CR. The median survival was 36 days (95%CI, 20.2-51.8). Univariate analysis showed that poor performance status (p = 0.028), T or NK/T cell lymphoma (p = 0.016), presence of jaundice (p = 0.063), the presence of DIC (p = 0.002), and poor clinical response to treatment (p < 0.001) predicted poor overall survival. These data suggest that the clinical features differ significantly between B cell LAHS and T or NK/T cell LAHS. Intensive treatment including high-dose chemotherapy and A-SCT should be investigated.

Malignant histiocytosis: a case report of a rare tumour presenting with spontaneous splenic rupture

Malignant histiocytosis is a rare invasive proliferation of neoplastic histiocytes. Cases previously reported as malignant histiocytosis were shown to be lymphomas of T or B lineage, especially anaplastic large-cell lymphomas. A case of malignant histiocytosis is described, in which a patient presenting with symptoms suggestive of pneumonia suddenly deteriorated and died. At autopsy, a large quantity of fresh blood, originating from several ruptured nodules on the enlarged spleen, was seen in the peritoneal cavity. Extensive infiltration by pleomorphic tumour cells and erythrophagocytosis by tumour cells were seen on histological examination of the spleen. Immunohistochemical analysis and staining were carried out. This is the second reported case of malignant histiocytosis presenting with spontaneous splenic rupture.

Monocyte/Macrophage-specific marker CD163+ histiocytic sarcoma: case report with clinical, morphologic, immunohistochemical, and molecular genetic studies

We report a case of a very rare disorder, histiocytic sarcoma, from a review of our autopsy cases. The neoplastic cells that proliferated in organs throughout the body were large cells containing eosinophilic cytoplasm and pleomorphic nuclei with prominent nucleoli. In the bone marrow, erythrophagocytosis by neoplastic cells was observed. The neoplastic cells were positive not only for lysozymes and CD68 (KP-1, PG-M1, and Ki-M1P) but also for a monocyte/macrophage-specific marker, CD163. In contrast, the results of tests for markers of myeloid cells, lymphoid cells, and epithelial cells were all negative. In a polymerase chain reaction study of paraffin-embedded tissues, analyses for the rearrangement of immunoglobulin heavy chain and T-cell receptor-gamma genes were negative. The current World Health Organization diagnostic criteria for histiocytic sarcoma regard immunohistochemical investigation as crucial. In this regard, the highly specific positivity for CD163 in this patient indicates that immunohistochemical staining of CD163 is very useful for the diagnosis of histiocytic sarcoma.

Histiocytic sarcoma with fatal duodenal ulcers

Histiocytic sarcoma is an uncommon neoplasm of mature histiocytes with very poor outcome. We report an autopsy case of a true histiocytic sarcoma with characteristic symptoms of so-called "malignant histiocytosis of the intestine". The liver and spleen were enlarged, with remarkable tumor cell infiltration in the hepatic sinusoids and splenic sinuses. Tumor cells aggregated to form sporadic nodular lesions in the liver, which often showed coagulative necrosis. Infarcted lesions also occurred at the splenic subcapsular area. In addition, tumor cell infiltration was noted in the sinuses of bone marrow and lymph node. Tumor cells often demonstrated moderate pleomorphism with multinucleated giant cells. They were positive for CD68 and negative for T- and B-cell lineage markers, megakaryocytic markers, and CD30. Various examinations were done to rule out infection-associated hemophagocytic syndrome, and the absence of infectious diseases was revealed. Thus, the diagnosis of histiocytic sarcoma was made. Apart from these lesions, multiple ulcerations, some with fatal perforation, were found in the esophagus and duodenum. They showed only non-specific inflammatory changes without tumor cell involvement. The ulcers probably derived from ischemic condition through an embolic process caused by tumor cell infiltration elsewhere in the blood vessels at the periphery of the ulcers.

Extranodal histiocytic sarcoma: clinicopathologic analysis of 14 cases of a rare epithelioid malignancy

Histiocytic sarcoma is a rare malignant neoplasm that occurs in lymph nodes, skin, and the gastrointestinal tract. Many previously published cases were likely misdiagnosed examples of non-Hodgkin lymphoma. Only small numbers of bona fide examples exist in the world literature; cases arising primarily at extranodal sites are not well described and often seem to go unrecognized. To characterize these tumors further, 14 extranodal histiocytic sarcomas were analyzed. Hematoxylin and eosin sections were reexamined, immunohistochemistry was performed, and clinical details were obtained from referring hospitals. Eight patients were female and 6 male (median age, 55 years; range, 15-89 years). All patients presented with a solitary mass, ranging in size from 1.8 to 12 cm (median 6.8 cm). Seven tumors arose in soft tissue (6 lower limb; 1 upper limb), 5 in the gastrointestinal tract (1 involving both stomach and colon, 1 ileum, 2 rectum, 1 anus), 1 in the nasal cavity, and 1 in the lung. Three gastrointestinal tract tumors also involved regional lymph nodes, and 1 involved the liver. Most cases had infiltrative margins. The tumors were generally composed of sheets of large epithelioid cells with abundant eosinophilic cytoplasm, oval to irregular nuclei, vesicular chromatin, and large nucleoli. Binucleated cells were common, and 6 cases contained tumor giant cells. Mitoses ranged from 1 to 64 per 10 HPF (median 11 per 10 HPF). Necrosis was present in 8 cases. Nearly all tumors showed a striking inflammatory infiltrate, most often of neutrophils or lymphocytes. All cases were reactive for LCA, CD45RO, and CD68 (KP1 and PG-M1); 13 of 14 (93%) expressed CD4, 12 of 14 (86%) lysozyme, 8 of 10 (80%) CD31, 7 of 14 (50%) S-100 protein, and 5 of 14 (36%) focal CD1a. Two tumors showed weak, focal cytoplasmic positivity for CD30, and 1 for epithelial membrane antigen. The tumors were negative for ALK-1, CD21, CD35, CD3, CD20, CD34, myeloperoxidase, HMB-45, and keratins. Gastrointestinal tract cases were negative for c-kit and desmin. Six patients were treated with postoperative radiation and 7 with chemotherapy (CHOP or ProMACE-MOPP). Follow-up was available for 10 patients (median, 24 months; range, 4 months to 11 years). Two tumors recurred locally, and 5 patients developed distant spread: 3 to lymph nodes, 1 to lung, and 1 to bone. At the last follow-up, 2 patients have died of disseminated disease, 4 and 5 months following initial diagnosis. The patients who died thus far had the largest primary tumors. Histiocytic sarcoma may arise primarily in soft tissue and shows reproducible histologic features, including abundant eosinophilic cytoplasm and a prominent inflammatory infiltrate. Metastatic carcinoma, metastatic melanoma, and large cell non-Hodgkin lymphomas should be excluded by immunohistochemistry. Histiocytic sarcoma has the potential for an aggressive clinical course, most often with lymph node involvement. However, a subset of cases presenting with clinically localized disease have a favorable long-term outcome. Tumor size may be a prognostic factor.

Histiocytic Sarcoma Associated With Idiopathic Myelofibrosis

We describe the case of a 39-year-old man with idiopathic myelofibrosis, who developed histiocytic sarcoma (true histiocytic lymphoma) 6 months after diagnosis. The patient developed generalized lymphadenopathy. A lymph node biopsy showed pronounced distension of the sinuses in the medulla and periphery, caused by the accumulation of large tumor cells. The tumor cells had abundant clear or eosinophilic cytoplasm. The nuclei were of various sizes and shapes, with condensed chromatin and prominent nucleoli. Some tumor cells displayed erythrophagocytosis. Immunohistochemically, the tumor cells were positive for CD68, α1-antitrypsin, CD45, CD45RO, and S100 protein, and were negative for B- and T-cell markers, CD30, CD1a, lysozyme, myeloperoxidase, factor VIII–related antigen, CAM 5.2, and HMB-45. Despite multiagent chemotherapy, the patient died of disease 25 months after diagnosis. Although histiocytic sarcomas are very rare, their recognition may be important for clinical and prognostic reasons.

Primary histiocytic sarcoma of the spleen associated with erythrophagocytic histiocytosis

We report an exceptional case of a histiocytic sarcoma presenting as a primary isolated spleen tumor in a 71-year-old woman. The neoplastic cells in the cords and sinuses of the red pulp formed multiple lobulated tumors, which were detected in vivo by ultrasound scan. The medium cells, large cells and the giant cells expressed CD68, a histiocyte-associated marker, lysozyme and S100 protein. All these cells were negative for B- and T-cell markers, cytokeratins, melanosome markers (HMB45) and CD1a (Langerhans' cells). Many tumor cells displayed strong erythrophagocytosis and sometimes lymphocytophagocytosis. In addition, numerous histiocytes with morphology indistinguishable from reactive macrophages also exhibited a strong erythrophagocytosis, and were found in the tumor as well as in the normal splenic parenchyma. Despite multi-agent chemotherapy, the patient suffered from a relapse in the liver, with a rapid fatal outcome. A literature review showed that such a primary splenic presentation with multiple tumors is rare. In contrast, in systemic malignant histiocytosis, secondary spleen involvement occurs more frequently but with diffuse infiltration. The association with a reactive histiocytosis with erythrophagocytosis corresponds to "histiocytic medullary reticulosis", as previously described by Scott and Robb-Smith.

Fine-needle aspiration cytology: True histiocytic lymphoma/histiocytic sarcoma

True histiocytic lymphoma/histiocytic sarcoma is an extremely rare, malignant histiocytic tumor. This report is of such a case in a 52-yr-old woman. Fine-needle aspiration (FNA) smears showed large pleomorphic nuclei, prominent nucleoli, moderately dense abundant cytoplasm, and scattered cells with cytoplasmic vacuoles and some with reniform nuclei. Small numbers of background lymphocytes and benign histiocytes were present as well as many multinucleated tumor cells. The immunophenotype was CD45, Lysozyme, CD68 (PGMI), CD43, and S-100 positive. Genotypic analysis revealed a germline configuration. This type of tumor has a large cytological differential diagnosis and immunophenotyping is essential for diagnosis.

Histiocytic lesions involving the bone marrow

Histiocytic lesions involving the bone marrow include a number of reactive and neoplastic disorders. This article discusses the morphologic, immunophenotypic, and genotypic features of a variety of diseases associated with histiocytes and/or monocytes. Lysosomal storage disorders and hemophagocytic syndromes are often first diagnosed by bone marrow examination. Granulomas involving the bone marrow may also be the first indication of a systemic disorder. Apart from acute and chronic monocytic leukemias, the bone marrow is rarely involved by malignant histiocytic disorders, of which Langerhans cell histiocytosis is the most common.

Peripheral T cell lymphoma-associated hemophagocytic syndrome in a patient with human adjuvant disease

Hemophagocytic syndrome (HPS) is a rare complication of lymphoma. We report a 70-year-old woman with human adjuvant disease who developed lymphoma-associated HPS (LAHPS) and elevated serum soluble interleukin (IL)-2 receptor. Despite intensive therapy, she died of pneumonia. Necropsy revealed a prominent spleen containing atypical T cells and many erythrophagocytizing histiocytes.

The serum cytokine profiles of lymphoma-associated hemophagocytic syndrome: a comparative analysis of B-cell and T-cell/natural killer cell lymphomas

To elucidate the differences in pathogenesis between lymphoma-associated hemophagocytic syndromes (LAHS) of the T-cell/ natural killer cell (T/NK) and B-cell (B) types, we comparatively analyzed the clinical features and serum cytokine profiles of 33 patients with LAHS registered in the Kyoto University Hematology/Oncology Study Group. The serum cytokine levels of each patient group (B-LAHS versus T/NK-LAHS) were expressed as the ratio of the median to the upper normal values of the respective cytokines and were as follows: 19.05 versus 13.99 for soluble interleukin 2 (IL-2) receptor, 0.67 versus 0.67 for granulocyte-macrophage colony-stimulating factor (GM-CSF), 0.64 versus 1.26 for G-CSF, 5.70 versus 3.61 for M-CSF, 1.54 versus 3.39 for interferon gamma (IFN-gamma), 13.17 versus 1.17 for IL-6, 6.88 versus 1.58 for tumor necrosis factor alpha (TNF-alpha), 0.71 versus 0.41 for IL-1beta, 1.99 versus 0.21 for IL-12, and 105.32 versus 29.65 for IL-10. The serum levels of IL-6, TNF-alpha, and IL-10 were significantly higher in the B-LAHS group, whereas those of IFN-y were significantly lower. These differences between the 2 groups may reflect a difference in the pathogenesis Higher serum levels of IL-6, TNF-alpha, and IL-10 may be derived at least partly from neoplastic B-cells themselves In addition, the extremely high serum levels of IL-10 suggest that a compensatory anti-inflammatory process may operate in both groups and give rise to a profound immunosuppressive state and a poor outcome.

Malignant histiocytosis in a domestic cat: cytomorphologic and immunohistochemical features

Malignant histiocytosis (MH) was diagnosed in a 13-year-old neutered male Domestic Shorthair cat on the basis of light microscopic and immunohistochemical findings. Thoracic fluid analysis showed a modified transudate which contained a very few atypical discrete cells. Cytologic and histologic evaluation of mediastinal and splenic masses revealed a pleomorphic population of large, discrete, round cells 10 to 30 micrometers in diameter with marked cellular atypia. Nuclei were oval to reniform, often with prominent, bizarre nucleoli. Multinucleated cells and mitotic figures were commonly seen. Erythro- and leucocytophagia were noted. Immunohistochemistry indicated a scattered positive staining pattern with the histiocytic antigenic marker Mac387 and a minor population of cells showing positive reactivity for lysozyme. This report describes the characterization of MH in a cat and emphasizes that MH should be considered as a differential diagnosis in proliferative disorders of discrete-cells in this species.

Effective control of infection-associated hemophagocytic syndrome with chloroquine

A retrospective study was carried out to evaluate the efficacy and the side effects of chloroquine in the treatment of 27 patients with infection-associated hemophagocytic syndrome and compared these with patients described in the literature. All patients received 20 to 25 mg/kg chloroquine per day orally for 7 days (a single course). Twenty-one patients who received one or two courses of treatment showed excellent responses; two patients showed no response to treatment. Two other patients refused to receive treatment with chloroquine. The response rate was 85.2%. Side effects were minimal and well tolerated. No relapses occurred in 19 patients. These results suggest that effective control of disease in some patients with infection-associated hemophagocytic syndrome can be achieved with chloroquine.

Localized and disseminated histiocytic sarcoma of dendritic cell origin in dogs

Canine histiocytic proliferative disorders include a wide spectrum of diseases characterized by different biologic behaviors. The etiology and pathogenesis of these diseases are largely unknown. The clinicopathologic, morphologic and immunophenotypic characteristics of canine localized and disseminated histiocytic sarcoma were examined in 39 dogs. Rottweilers, Bernese Mountain Dogs, and retrievers were most commonly affected (79%). Localized histiocytic sarcomas (19 dogs) arose from a single site, and metastatic lesions were observed in draining lymph nodes. Predilection sites were subcutis and underlying tissues on extremities, but tumors occurred in other locations, including spleen, lung, brain, nasal cavity, and bone marrow. Disseminated histiocytic sarcomas (20 dogs), a multisystem disease previously described as malignant histiocytosis, primarily affected spleen, lungs, bone marrow, liver, and lymph nodes. Both localized and disseminated canine histiocytic sarcomas were composed of pleomorphic tumor cell populations. CD1+, CD4-, CD11c+, CD11d-, MHC II+, ICAM-1 +, Thy-1 +/- tumor cells were identified in all snap-frozen samples (31 dogs). This phenotype is characteristic for myeloid dendritic antigen-presenting cell lineage. Hence, canine localized and disseminated histiocytic sarcomas are likely myeloid dendritic cell sarcomas. Dendritic antigen-presenting cells are a heterogeneous cell population with regards to their ontogeny, phenotype, function, and localization. The exact sublineage of the proliferating dendritic antigen-presenting cells involved in canine histiocytic sarcomas remains to be determined. Phenotypic analysis of formalin-fixed tissues from eight dogs was limited by available markers. Morphologic features and the phenotype CD18+, CD3-, and CD79a- were the most useful criteria to indicate likely histiocytic origin.

Primary histiocytic lymphoma of the central nervous system: a neoplasm frequently overshadowed by a prominent inflammatory component

True histiocytic lymphoma, as defined by strict criteria, is a very rare neoplasm. We describe three cases occurring as primary tumors in the central nervous system. The patients, two females and one male, ranged in age from 11 to 69 years. The tumors involved the brain in two cases and spinal cord in one, with a size ranging from 7 to 17 mm. Two patients died at 4 months and 8 months, respectively, and one was alive with disease at 5 months. Pathologically, the tumors comprised groups and sheets of noncohesive large cells with pleomorphic vesicular nuclei, distinct nucleoli, and abundant eosinophilic cytoplasm. A dense inflammatory infiltrate consisting of neutrophils, lymphocytes, plasma cells, and histiocytes was present, with multiple foci of necrosis and abscess formation. All three cases demonstrated an identical immunophenotype: positive for CD68 and lysozyme; focally positive for S-100 protein, CD45RB, and CD4; and negative for CD3, CD20, CD21/CD35, CD1a, CD30, ALK1, myeloperoxidase, glial fibrillary acidic protein, and cytokeratin. The proliferative index ranged from 20% to 35%. Ultrastructural examination further confirmed the histiocytic nature of the tumor cells, characterized by irregularly folded or multisegmented nuclei and abundant cytoplasm containing lysosomes; Birbeck granules, interdigitating cell processes, and cell junctions were not found. Although the presence of abundant inflammatory cells could obscure the neoplastic histiocytes, making the distinction from inflammatory conditions difficult, awareness of this unusual histologic feature and the invariable finding of pleomorphic cells in some areas of the lesion permit the correct diagnosis to be made.

Translocation (14;19)(q32;q13) detected by spectral karyotyping and lack of BCL3 rearrangement in CD5-positive B-cell lymphoma associated with hemophagocytic syndrome

It has been shown that some cases of B-cell non-Hodgkin lymphoma associated with a hemophagocytic syndrome (B-LAHS) have chromosomal abnormalities at 14q32 or 19q13. We report here a 64-year-old woman with B-LAHS and a complex karyotype including add(14)(q32). We applied spectral karyotyping and revealed that the add(14)(q32) was derived from a der(14)t(14;19)(q32;q13). However, rearrangement of the BCL3 gene at 19q13 could not be detected by Southern blot analysis. Our results indicate that the translocation involving 19q13 may be one of the recurrent aberrations in B-LAHS and that the molecular mechanism of t(14;19)(q32;q13) in B-LAHS appear to be different from that observed in chronic lymphocytic leukemia.

Combined histologic and molecular features reveal previously unappreciated subsets of lymphoma in AKXD recombinant inbred mice

Hematopoietic neoplasms developing in AKXD recombinant inbred, NFS.V(+) and ICSBP knockout mice were assessed using morphologic, cytologic and molecular criteria that relate these disorders to human lymphoma and leukemia. Lymphoma types included precursor T-cell and B-cell lymphoblastic, small lymphocytic, splenic marginal zone, follicular, and diffuse large cell (DLCL). In addition to previously defined subtypes of DLCL composed of centroblasts or immunoblasts, two additional subtypes are defined here: lymphoblastic lymphoma like (LL) and lymphoma characterized by a histiocytic reaction (HS). DLCL(HS) were distinguished from true histiocytic lymphomas by the presence of clonal Ig gene rearrangements.

Bone marrow involvement in lymphomas with hemophagocytic syndrome at presentation: a clinicopathologic study of 11 patients in a Western institution

Hemophagocytic syndrome (HPS) is a clinicopathologic syndrome that can reveal a non-Hodgkin's lymphoma. The pathologic features of lymphoma associated with HPS remain ill defined. We studied 11 lymphomas associated with HPS on initial bone marrow biopsies, consecutively diagnosed during a 6-year period in a Western institution. There were seven diffuse large B-cell lymphomas (DLBCLs), three T-cell lymphomas (one peripheral T-cell lymphoma unspecified, two hepatosplenic gammadelta T-cell lymphomas [HS gammadeltaTLs]), and one aggressive NK-cell lymphoma/leukemia (NKL). These lymphomas shared common clinicopathologic features with a systemic presentation, a poor outcome (nine patients died within 2 years), and a mild interstitial lymphoid infiltrate of the bone marrow at presentation in nine patients. This equivocal lymphoma infiltrate was blending with normal hematopoietic cells, and CD20 and CD3 immunolabelings were essential for its detection. A high number of reactive T (CD3+) cells, most often with a predominant cytotoxic (CD8+ TiA1+) phenotype, was present in all DLBCLs. By in situ hybridization, Epstein-Barr virus was detected in neoplastic cells of three cases (one DLBCL, one HS gammadeltaTL, and one NKL), which also showed serum viral DNA. Polymerase chain reaction studies disclosed HHV6 DNA sequences in tumor tissues of two DLBCLs, whereas HHV8 DNA was not detected. Because tumor mass indicative of lymphoma was not striking in most patients, bone marrow biopsy appears to be of great value for the diagnosis of an HPS-associated lymphoma, which may be, in Western patients, of B- as well as T- or NK-cell type. Immunostaining for CD3 and CD20 is essential to identify the common subtle lymphoma involvement. Together with a better understanding of the pathogenic processes, an early diagnosis may improve the prognosis of HPS-associated lymphoma.

Anaplastic large cell lymphoma: the shifting sands of diagnostic hematopathology

Anaplastic large cell lymphoma (ALCL) is a paradigm for the process used to define new disease entities, and provides a model that is applicable to all areas of pathology. ALCL was first recognized based on characteristic histologic features (sinusoidal invasion) and a distinctive immunophenotype (CD30+). However, neither sinusoidal invasion nor CD30-positivity proved to be entirely specific. Subsequently, a characteristic cytogenetic abnormality was identified, the t(2;5), that led to identification of the genes involved in the translocation (NPM/ALK) and insights into the pathogenesis. Generation of monoclonal antibodies to the aberrantly expressed anaplastic large cell lymphoma kinase (ALK) such as ALK-1 can be used diagnostically, and have led to improved definition of the diagnostic entity with important clinical and prognostic implications. These studies also have clarified the relationship of ALCL to Hodgkin's disease, another lymphoid malignancy associated with CD30 expression. We have learned that the ultimate histologic spectrum of ALCL is both narrower and broader than originally believed. The small cell and lymphohistiocytic variants of ALCL are ALK-positive, and are an accepted part of the disease entity, although the neoplastic cells may appear neither large nor anaplastic. Conversely, most cases of Hodgkin's-like ALCL have proved to be more closely related to true Hodgkin's disease, and are unrelated to ALCL.

Hepatic manifestations of hemophagocytic syndrome: a study of 30 cases

OBJECTIVE

Hemophagocytic syndrome has been defined as the combination of a proliferation of cytologically benign, actively phagocytic macrophages in bone marrow, spleen, or lymph nodes in association with fever, cytopenia, splenomegaly, and hypertriglyceridemia. Hepatic dysfunction is often present but the nature of the hepatic lesions and related manifestations have not been fully characterized. The aim of this study was to ascertain the features of hepatic involvement in hemophagocytic syndrome.

METHODS

Thirty patients with hemophagocytic syndrome were retrospectively studied. Inclusion criteria included: 1) bone marrow with hemophagocytic histiocytosis, 2) clinical or biological signs of hepatic involvement, and 3) available liver specimen.

RESULTS

The association of fever, jaundice, and hepatomegaly or splenomegaly was present in 50% of the patients. Median value for serum alanine transaminase activity was five times the upper limit of normal values (range, 0.3-125), for serum alkaline phosphatase activity 2.7 upper limit of normal values (range, 0.2-47.7), for total bilirubin 136 micromol/L (range, 4-681 micromol/L), and for factor V 70% (range, 19-145%). Sinusoidal dilatation with hemophagocytic histiocytosis were found in the biopsy specimen in all patients. An underlying condition potentially responsible for altered immune function (lymphoma, leukemia, liver transplantation) was identified in 29 patients. Liver biopsy was diagnostic for the underlying condition in 15 patients (including eight cases with nonspecific bone marrow biopsy findings). High serum bilirubin, elevated serum alkaline phosphatase activity, low factor V level, and lack of treatment for the underlying disease were associated with a poor prognosis.

CONCLUSIONS

Hemophagocytic syndrome should be suspected in immunodeficient patients with fever, jaundice, and hepatosplenomegaly. Hepatic lesions are characterized by nonspecific sinusoidal dilatation with hemophagocytic histiocytosis and in 50% of the patients by alterations specific to the underlying condition. Liver biopsy is a useful diagnostic procedure in patients with this clinical presentation.

An Asian variant of intravascular large B-cell lymphoma: clinical, pathological and cytogenetic approaches to diffuse large B-cell lymphoma associated with haemophagocytic syndrome

Diffuse large B-cell lymphoma with haemophagocytic syndrome (BCL-HS) has been reported mainly in Asia and is regarded as a distinct variant of intravascular lymphoma (IVL). However, it is unclear whether all cases of BCL-HS fall within the framework of IVL and available clinical information is limited. We analysed 25 cases with BCL-HS, including 11 autopsied cases (median, 66 years; male-female ratio, 1.1:1). The patients presented with fever, anaemia, thrombocytopenia, hepatosplenomegaly, haemophagocytosis, bone marrow invasion, respiratory disturbance and disseminated intravascular coagulopathy, but usually lacked lymphadenopathy, mass formation, neurological abnormalities and skin lesions. The clinical course was aggressive with a median survival of 7 months. The morphological findings were uniform: large lymphoid cells infiltrated vessels and/or sinusoids of the liver, marrow, lung, kidney and other organs. They were positive for CD19, CD20, CD79a and HLA-DR, but negative for CD10, CD23 and CD30. CD5 was positive in five out of 17 cases. Our critical review indicates that BCL-HS is the equivalent of the Asian variant of IVL.

Pathobiology of NPM-ALK and variant fusion genes in anaplastic large cell lymphoma and other lymphomas

Despite its clinical and histological heterogeneity, anaplastic large cell lymphoma (ALCL) is now a well-recognized clinicopathological entity accounting for 2% of all adult non-Hodgkin's lymphomas (NHL) and about 13% of pediatric NHL. Immunophenotypically, ALCL are of T cell (predominantly) or Null cell type; by definition, cases expressing B cell antigens are officially not included in this entity. The translocation (2;5)(p23;q35) is a recurring abnormality in ALCL; 46% of the ALCL patients bear this signature translocation. This translocation creates a fusion gene composed of nucleophosmin (NPM) and a novel receptor tyrosine kinase gene, named anaplastic lymphoma kinase (ALK). The NPM-ALK chimeric gene encodes a constitutively activated tyrosine kinase that has been shown to be a potent oncogene. The exact pathogenetic mechanisms leading to lymphomagenesis remain elusive; however, the synopsis of evidence obtained to date provides an outline of likely scenarios. Several t(2;5) variants have been described; in some instances, the breakpoints have been cloned and the genes forming a new fusion gene with ALK have been identified: ATIC-ALK, TFG-ALK and TPM3-ALK. Cloning the translocation breakpoint and identifying the ALK and NPM genes provided tools for screening material from patients with ALCL using various approaches at the chromosome, DNA, RNA, or protein level: positive signals in the reverse transcriptase-polymerase chain reaction (RT-PCR) and the immunostaining with anti-ALK monoclonal antibodies (McAb) serve as the most convenient tests for detection of the t(2;5) NPM-ALK since the fusion gene and ALK protein expression do not occur in normal or reactive lymphoid tissue. The wide range of NPM-ALK positivity reported in different series appears to be dependent on the inclusion and selection criteria of the ALCL cases studied. Overall, however, 43% of ALCL cases were NPM-ALK+ (83% of pediatric ALCL vs 31% of adult ALCL). Occasional non-ALCL B cell lymphomas (4%) with diffuse large cell and immunoblastic histology and Hodgkin's disease cases (3%) were NPM-ALK-, but these data are questionable. The aggregate results indicate that, in contrast to primary nodal (systemic) ALCL, the t(2;5) may be present in only 10-20% of primary cutaneous ALCL and rarely, if at all, in lymphomatoid papulosis, a potential precursor lesion; however, these 10-20% positive cases were not confirmed by anti-ALK McAb immunostaining and may represent an overestimate. Positivity for NPM-ALK is associated to various degrees with the following parameters: 44% and 45% of ALCL cases with T cell and Null cell immunophenotype, respectively, are positive, whereas only 8% of cases with a B cell immunoprofile are positive; the mean age of positive patients is significantly younger than that of negative patients; positive cases carry a better overall prognosis (but not in all studies). Recently, the homogenous category of ALK lymphoma ('ALKoma') has emerged as a distinct pathological entity within the heterogenous group of ALCL. The fact that patients with ALK lymphomas experience significantly better overall survival than ALK- ALCL demonstrates further that analysis of ALK expression has important prognostic implications. The term ALK lymphoma signifies a switch in the use of the diagnostic criteria: cases are selected on the basis of a genetic abnormality (the ALK rearrangement), instead of the review of morphological or immunophenotypical features which are clearly more prone to disagreement and controversy. Since its initial description in 1985 ALCL has become one of the best characterized lymphoma entities.

B-cell lymphoma-associated hemophagocytic syndrome

B-cell lymphoma-associated hemophagocytic syndrome (B-LAHS) is extremely rare in Western countries but has recently been increasingly reported in Asian countries, especially Japan. Here, we reviewed 25 previously reported Japanese cases of B-LAHS and summarized its clinicopathologic features and therapeutic outcome. The median age of onset was 63 years old with initial presentation of fever, hepatomegaly, and splenomegaly without associated lymphadenopathy. Laboratory findings showed increased levels of lactate dehydrogenase, C-reactive protein, ferritin and soluble interleukin-2 receptor. Histopathologically, hemophagocytosis was often seen in the bone marrow and spleen. Various percentages of lymphoma cells were seen in the bone marrow, positive for CD19, CD20 and surface immunoglobulin. and some were also positive for CD5. Cytogenetic analysis showed a complex structural abnormality including chromosome 14q32, 19q13 and deletion of the terminal part of 8p21. Some patients had histological features of intravascular lymphomatosis (IVL). The prognosis was poor with a median survival period of 9 months. We treated five patients using autologous peripheral blood stem cell transplantation (PBSCT), and four are still in complete remission nine to 24 months after PBSCT, suggesting that high-dose chemotherapy followed by PBSCT might improve the survival rate.

Marked histiocytosis in the portal tract in a patient with reactive hemophagocytic syndrome: An autopsy case

We report an autopsy case of reactive hemophagocytic syndrome with peculiar liver histology. A 71-year-old female was diagnosed as having acute myelogenous leukemia and treated with chemotherapy. During her course, methicillin-resistant Staphylococcus aureus (MRSA) was noted in blood culture and she was diagnosed as having MRSA sepsis. She died of respiratory failure 5 months after the onset of leukemia and 10 days after the MRSA sepsis. Ante-mortem liver function tests were within normal ranges. At autopsy, myeloblastic leukemia cells positive for CD13 were present in the bone marrow and, to a much lesser extent, in the spleen and liver. Numerous histiocytes of a bland appearance with erythrophagocytosis were noted in the bone marrow and spleen. The histiocytes were positive for CD68, but negative for S-100 and lysozymes. In the liver, many histiocytes of bland appearance with erythrophagocytosis and CD68 positivity were present in the portal tracts with no Kupffer cell hyperplasia. There were no hepatocellular degeneration, fatty changes or sinusoidal dilations. We consider that this histiocytosis was associated with MRSA infection and diagnosed this as infection-associated hemophagocytic syndrome. In previously reported cases, hemophagocytosis in hyperplastic Kupffer cells was the main liver change of reactive hemophagocytic syndrome. The present case suggests that marked histiocytosis in portal tracts only may be a main feature of liver changes in reactive hemophagocytic syndrome and that such cases may not show abnormal liver function tests.

An Asian variant of intravascular lymphomatosis: an updated review of malignant histiocytosis-like B-cell lymphoma

Malignant histiocytosis-like B-cell lymphoma (MH-like BCL) is characterized clinically by hemophagocytic syndrome (HPS), bone marrow involvement at presentation, and an aggressive clinical course. Yet, it remains an ill-defined disease entity. We recently described five cases of MH-like BCL and suggested that these may be regarded as a peculiar variant of intravascular lymphomatosis (IVL), based on clinical and pathological observation. Interestingly, this type of lymphoma has been reported exclusively among Asians, with few reports from Western countries, and therefore we propose that this variant be noted as an Asian variant of IVL(AIVL). To evaluate the incidence of this variant, we performed a literature search for English or Japanese studies dealing with MH-like BCL or B-cell IVL associated with HPS (IVL with HPS). We found 18 reports of MH-like BCL and 16 reports of IVL with HPS and re-evaluated the clinicopathologic aspects of each study with respect to AIVL. Although several differences were noted, such as gender, presence of respiratory changes, bone marrow invasion and disseminated intravascular coagulopathy, there were also overlapping profiles and they appeared to be consistent with the AIVL single disease entity. Of particular note was the absence of peripheral lymphadenopathy and tumor formation which posed diagnostic problems in the initial phase of the presentations. Thus, based on analysis of the clinical findings of these 34 cases, the diagnostic criteria for AIVL consists primarily of cytopenia (anemia and/or thrombocytopenia), hepatosplenomegaly, absence of peripheral lymphadenopathy and tumor formation, and erythrocyte-hemophagocytosis along with intravascular proliferation of the neoplastic B cells. The pathologic findings of the 19 autopsied cases which fulfilled the criteria are also summarized, and they reveal morphologic, immunologic, and genotypic features of typical IVL.

B-cell lymphoma associated with haemophagocytic syndrome: a clinical, immunological and cytogenetic study

B-cell lymphoma associated with haemophagocytic syndrome (HPS) is extremely rare in Western countries but has recently been increasingly reported in Asian countries. We describe seven patients with B-cell lymphoma associated with HPS, six males and one female, age range 41-82 years (median 63 years). All patients had fever and splenomegaly, and six of the seven patients had hepatomegaly with no associated lymphadenopathy. The bone marrow showed haemophagocytosis and an infiltration of lymphoma cells. All patients showed increased levels of lactate dehydrogenase, C-reactive protein, ferritin and soluble interleukin-2 receptor. Lymphoma cells were positive for CD19. CD20 and surface immunoglobulin in all patients examined, and positive for CD5 in four of seven patients. Cytogenetic analyses of bone marrow cells showed a complex structural abnormality including chromosome 14q32 in two patients, 19q13 in three patients and deletion of the terminal part of 8p21 in six patients. The prognosis was poor; only two of the seven patients have survived in complete remission with a median survival of 11 months. These data suggested that B-cell lymphoma associated with HPS might constitute a distinct biological and clinical disease entity. Abnormality of chromosome 19q13 and loss of 8p21 might be involved in the pathogenesis of this disease.

True histiocytic lymphoma: a morphologic, immunohistochemical, and molecular genetic study of 13 cases

We describe the morphologic, immunohistologic, and genotypic characteristics of 13 cases of true histiocytic lymphomas. Six cases presented with primary gastrointestinal involvement, five with lymphadenopathy, the other sites involved being the bone marrow and the skin. The neoplastic cells displayed large abundant eosinophilic cytoplasm, occasionally vacuolated with folded or bizarre-shaped nuclei with prominent nucleoli. Mitotic figures were numerous. Multinucleated cells were common. The pattern of growth was usually diffuse and noncohesive. Spindle cell sarcoma-like areas were evident in five cases, with a prominent foam cell component in four cases. All cases expressed histiocyte-associated markers (CD68, lysozyme, alpha-1-antitrypsin), CD45 or CD45RO, and were negative for CD1a, epithelial, and B- and T-cell lineage-specific markers. Reactivity for S-100 was observed in a variable proportion of cells in 11 cases. The proliferation fraction varied from 3 to 88%. Genotypic analysis for T-cell receptor or immunoglobulin gene rearrangement demonstrated a germline configuration in all cases. We demonstrate that true histiocytic lymphoma is a rare distinctive pathologic entity that may be defined by immunohistochemical criteria and that recognition among histiocytic disorders is important for clinical and prognosis reasons.