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

Histiocytic Sarcoma Associated with Coombs Negative Acute Hemolytic Anemia: A Rare Presentation

Histiocytic sarcoma (HS) rarely involves extranodal sites, such as the spleen. We report a unique pediatric case of massive splenomegaly and refractory Coombs negative hemolytic anemia (CNHA) secondary to HS. The CNHA resolved completely after an emergent splenectomy. Next generation sequencing (NGS) revealed novel ASXL1, PTPN11, KIT, and TP53 mutations, unmasking a clonal heterogeneity within the same neoplasm.

A rare case of paediatric histiocytic sarcoma of the maxilla and mandible

Histiocytic sarcoma is an extremely rare malignant neoplastic proliferation of the haematopoietic cells. Very few cases have been reported in the paediatric age group. Imaging features have been rarely described in the literature. It can involve any region of the body; however, it most commonly involves the lymph nodes. Its imaging appearance can mimic lymphoproliferative disorders; however, with the advent of new immunohistochemical markers, the diagnosis of HS has become more reliable. We report an unusual case of primary bone involvement by HS with multiple lesions in the facial bones of a 2-year-old female who presented with tooth and mandibular tenderness.

Comparative oncology: what dogs and other species can teach us about humans with cancer

Over 1.66 million humans (approx. 500/100,000 population rate) and over 4.2 million dogs (approx. 5300/100,000 population rate) are diagnosed with cancer annually in the USA. The interdisciplinary field of comparative oncology offers a unique and strong opportunity to learn more about universal cancer risk and development through epidemiology, genetic and genomic investigations. Working across species, researchers from human and veterinary medicine can combine scientific findings to understand more quickly the origins of cancer and translate these findings to novel therapies to benefit both human and animals. This review begins with the genetic origins of canines and their advantage in cancer research. We next focus on recent findings in comparative oncology related to inherited, or genetic, risk for tumour development. We then detail the somatic, or genomic, changes within tumours and the similarities between species. The shared cancers between humans and dogs that we discuss include sarcoma (osteosarcoma, soft tissue sarcoma, histiocytic sarcoma, hemangiosarcoma), haematological malignancies (lymphoma, leukaemia), bladder cancer, intracranial neoplasms (meningioma, glioma) and melanoma. Tumour risk in other animal species is also briefly discussed. As the field of genomics advances, we predict that comparative oncology will continue to benefit both humans and the animals that live among us.

Histiocytic sarcoma as a secondary malignancy: pathobiology, diagnosis, and treatment

Histiocytic sarcoma (HS) is an extremely rare non-Langerhans cell disorder with an aggressive course and limited treatment options. Recent advances in molecular/genetic sequencing have suggested a common clonal origin between various hematolymphoid disorders and cases of secondary HS. Deriving conclusions from previously reported cases of HS arising secondarily to certain hematolymphoid disorders, here we have tried to provide insight into the mechanisms influencing this evolution. We also discuss a clinical case of a 72-year-old man with a diagnosis of chronic myeloid leukemia (CML), presenting subsequently with a heterogeneous liver mass positive with a diagnosis of HS. The liver mass showed a retained BCR-ABL1 translocation suggesting clonality between the CML and HS. As seen in our case and other reported cases of HS derived secondarily, the concurrent expression of immunoglobulin heavy (IGH)-/light-chain rearrangements or cytogenetic markers common to the primary malignancy suggests an evolutionary mechanism involving lineage switching that could potentially be influenced by genetic or epigenetic cues which may occur at the level of a progenitor or the malignant cell itself.

Central Nervous System and Head and Neck Histiocytoses: A Comprehensive Review on the Spectrum of Imaging Findings

The histiocytoses are a rare group of varied but related disorders characterized by abnormal tissue proliferation of macrophages and dendritic cells within tissues. The purpose of this article was to review the imaging findings in patients presenting with CNS and with head and neck manifestations of these disorders. Histiocytoses include but are not limited to Rosai-Dorfman disease, Erdheim Chester disease, Langerhans cell histiocytosis, histiocytic sarcoma, and juvenile xanthogranuloma. A review of the literature was performed to determine the sites of disease involvement. This article includes the demographics, histopathologic criteria for diagnosis, and imaging features of these histiocytoses, and describes the manifestations in locations known to harbor disease: intraaxial and extra-axial intracranial regions, the calvaria, skull base, hypothalamopituitary axis, orbits, paranasal sinuses, spine, and the head and neck region. Histiocytoses have variable imaging appearances in the CNS and in the head and neck region, and radiologists should be aware of the spectrum of findings to avoid mistaking them for other disease processes.

Learning Objective

To understand the general pathophysiology, clinical presentation, and typical imaging characteristics of the most common histiocytoses; comprehend the morphologic and immunohistochemical characteristics of these histiocytoses and the hallmark findings on pathology; and be able to differentiate between these disorders based on their most common presentations.

Non-mesenchymal Mimics of Sarcoma

A variety of different non-mesenchymal neoplasms may mimic sarcoma, in particular sarcomatoid carcinoma and melanoma, but also mesothelioma and rarely some lymphomas. This article reviews the key clinical and histologic features of such neoplasms in different settings, along with the use of ancillary studies to help identify the tumor types most frequently misdiagnosed as sarcoma.

Impact of surgery, radiation and systemic therapy on the outcomes of patients with dendritic cell and histiocytic sarcomas

BACKGROUND

Neoplasms of histiocytic and dendritic cell origin, including follicular dendritic cell sarcoma (FDCS), histiocytic sarcoma (HS) and interdigitating dendritic cell sarcoma (IDCS), are extremely rare, and data on their natural history and treatment outcomes are sparse. We evaluated the impact of surgery, radiation and systemic therapies on overall survival (OS).

METHODS

We conducted a retrospective chart review of patients with FDCS, IDCS and HS treated at Memorial Sloan Kettering Cancer Center between 1995 and 2014.

RESULTS

We identified 31, 15 and 7 patients with FDCS, HS and IDCS, respectively. Median age was 48.7, 42.3 and 58.8years for FDCS, HS and IDCS, respectively. Only a slight disparity in gender distribution existed for FDCS and HS; however, IDCS predominantly affected males (6:1). The most common sites of presentation were abdomen and pelvis (42%), extremities (33%) and head and neck (57%) for FDCS, HS and IDCS, respectively. At diagnosis, 74%, 40% and 86% of patients presented with localised disease in FDCS, HS and IDCS, respectively. Patients with localised disease had significantly improved OS than those with metastatic disease in FDCS (P=0.04) and IDCS (P=0.014) but not in HS (P=0.95). In FDCS and HS, adjuvant or neo-adjuvant therapy was not associated with improved OS compared with observation. In IDCS, surgery alone provided a 5-year overall survival rate of 71%.

CONCLUSIONS

Adjuvant or neo-adjuvant treatment in FDCS and HS did not affect OS. Patients with IDCS had an excellent outcome with surgery. In the metastatic setting, chemotherapy and small molecule inhibitors may provide benefit.

Histiocytic sarcoma combined with acute monocytic leukemia: a case report

Background

Histiocytic sarcoma (HS) is a rare malignant tumor. Underlying or associated disorders have been reported in some patients with HS. We herein report a very rare case of HS combined with acute monocytic leukemia (AMoL).

Case presentation

A 62-year-old man presented with systemic lymph node enlargement and pancytopenia in August 2012. Bone marrow (BM) aspirate showed abnormal hematopoiesis with 3 % blast, but no obvious abnormalities on flow cytometric immunophenotyping. A BM cytogenetic study and fluorescence in situ hybridization revealed a 46, XY karyotype and no myelodysplastic syndrome-associated features, respectively. A right cervical node biopsy showed disrupted node structure with diffuse pleomorphic neoplastic cells that were positive for cluster of differentiation (CD) 68, MAC387 and lysozyme, but negative for CD1a, CD21, CD30, S100, and T-cell, B-cell, and myeloid lineage markers. The patient was diagnosed with HS and treated with 8 courses of CHOP chemotherapy. After 4 courses, total-body FDG-PET imaging showed partial remission and disappearance of abnormal hematopoiesis in the BM, but 2 % blasts remained. Lymphadenopathy and pancytopenia recurred 1 month after the his last chemotherapy dose. He became resistant to second-line chemotherapy, with gradually increasing leukocytes, up to 50 % blasts in BM in December 2013, and abnormal cells positive for CD117, CD13, CD33, HLA-DR, CD34, CD11c, CD38, and myeloperoxidase. He was diagnosed with acute monocytic leukemia (AMoL-M5), and treated by CAG regimen + decitabine, but died of severe pneumonia and hepatic failure.

Conclusion

To our knowledge, this is the first case of HS combined with AMoL. The coexistence of these two neoplasms was shown by the lymph node biopsy findings and BM myeloid markers. The patient had a transient response to chemotherapy and a poor prognosis. Whether these two neoplasms were related is unclear; however, if so, we suspect the combination might be caused by a malignant transformation of a promonocyte or stem cell, upstream of histiocytes and monocytes.

Flow cytometry used to identify histiocytic sarcoma: A case report

Histiocytic sarcoma (HS) is an extremely rare but aggressive malignancy of hematopoietic origin. The diagnosis of HS mainly relies on pathological morphology and immunohistochemical staining combined with clinical symptoms. However, whether histiocytic sarcoma can be detected using flow cytometry (FCM) is not clear. We report the case of a 61-year-old female patient with a group of abnormal cells identified primarily by FCM. Largeabnormal cells -CD68⁺ CD11c⁺ CD14⁺ HLA-DR⁺ CD123⁺ CD45⁺ presented in upper forward scatter and side scatter, indicating that a malignancy originally derived from monocyte/macrophage could be histocytic sarcoma. This patient with histiocytic sarcoma was finally confirmed with pathology and immunohistochemistry. In conclusion, HS can be detected by assessment of CD68⁺ CD11c⁺ CD14⁺ HLA-DR⁺ CD123⁺ CD45⁺ cells using FCM, suggesting that FCM can be an effective tool for early finding of HS. © 2015 International Clinical Cytometry Society.

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.

Dendritic cell and histiocytic neoplasms: biology, diagnosis, and treatment

BACKGROUND

Dendritic and histiocytic cell neoplasms are rare malignancies that make up less than 1% of all neoplasms arising in lymph nodes or soft tissues. These disorders have distinctive disease biology, clinical presentations, pathology, and unique treatment options. Morphology and immunohistochemistry evaluation by a hematopathologist remains key for differentiating between these neoplasms. In this review, we describe tumor biology, clinical features, pathology, and treatment of follicular dendritic cell sarcoma, interdigitating dendritic cell sarcoma, indeterminate dendritic cell sarcoma, histiocytic sarcoma, fibroblastic reticular cell tumors, and disseminated juvenile xanthogranuloma.

METHODS

A literature search for articles published between 1990 and 2013 was undertaken. Articles are reviewed and salient findings are systematically described.

RESULTS

Patients with dendritic cell and histiocytic neoplasms have distinct but variable clinical presentations; however, because many tumors have recently been recognized, their true incidence is uncertain. Although the clinical features can present in many organs, most occur in the lymph nodes or skin. Most cases are unifocal and solitary presentations have good prognoses with surgical resection. The role of adjuvant therapy in these disorders remains unclear. In cases with disseminated disease, prognosis is poor and data on treatment options are limited, although chemotherapy and referral to a tertiary care center should be considered. Excisional biopsy is the preferred method of specimen collection for tissue diagnosis, and immunohistochemistry is the most important diagnostic method for differentiating these disorders from other entities.

CONCLUSIONS

Dendritic cell and histiocytic cell neoplasms are rare hematological disorders with variable clinical presentations and prognoses. Immunohistochemistry remains important for diagnosis. Larger pooled analyses or clinical trials are needed to better understand optimal treatment options in these rare disorders. Whenever possible, patients should be referred to a tertiary care center for disease management.

CD68 expression is a discriminative feature of indolent cutaneous CD8-positive lymphoid proliferation and distinguishes this lymphoma subtype from other CD8-positive cutaneous lymphomas

BACKGROUND

Indolent cutaneous CD8+ lymphoid proliferation is a recently described rare entity among cutaneous T-cell lymphomas that typically presents with solitary skin lesions at acral sites. Separation from otherwise aggressive T-cell lymphomas bearing a cytotoxic CD8+ phenotype is fundamental to avoid unnecessary harmful treatment. However, up to now, no reliable discriminative marker has been identified.

OBJECTIVES

Motivated by these diagnostic quandaries, we have analyzed a large series of archived formalin-fixed paraffin-embedded (FFPE) specimens of atypical CD8+ cutaneous infiltrates with clear-cut diagnosis and clinical follow-up (n = 44) including five cases of indolent CD8+ lymphoid proliferation by using immunohistochemistry with the aim of obtaining markers predictive of subtype assignment.

RESULTS

We identified exclusive expression of CD68 by lymphoma cells within the subgroup of indolent CD8+ lymphoid proliferation (5/5 cases). Specific CD68 expression in this entity was confirmed by the application of several monoclonal antibodies (KP1, PG-M1, KiM1P) against the CD68 molecule available for FFPE tissue. In contrast, none of the infiltrates of the other CD8+ cutaneous lymphoma entities stained positive for CD68 (0/39).

CONCLUSIONS

Based on these observations, we suggest CD68 as a new discriminative marker which is helpful in distinguishing indolent CD8+ lymphoid proliferation from other CD8+ cutaneous lymphomas in ambiguous cases.

Fine needle aspiration of Histiocytic sarcoma

Histiocytic sarcoma is derived from histiocytes and is among the rarest of the tumors affecting the lymphoid tissue. We report a case of a histiocytic sarcoma arising from the lymph node in a 35-year-old male who came for a fine needle aspiration cytology and a subsequent biopsy was conducted and the tissue subjected to hematoxylin and eosin and immunohistochemistry staining.

The spectrum of rare morphological variants of cutaneous epithelioid angiosarcoma

AIMS

Unusual cytoplasmic alterations have recently been reported in poorly differentiated cutaneous angiosarcoma, making an accurate diagnosis challenging. As these tumours remain poorly documented, we aimed to study their clinicopathological characteristics more comprehensively.

METHODS AND RESULTS

Six cutaneous angiosarcomas with unusual cytoplasmic alterations were identified from referral files. All tumours arose as nodules or plaques (range: 05-195 mm) on sun-damaged skin of the head and neck of elderly males (median age: 76.5 years). Histologically, the tumours were composed of enlarged epithelioid cells showing prominent signet ring (n = 3), foam (n = 2) or granular cell (n = 1) change. Vasoformative elements were only focally noted. By immunohistochemistry, all tumours expressed CD31 and avian v-ets erythroblastosis virus E26 oncogene homologue (ERG). Foam cell change was associated with additional expression of CD68 and CD163. Follow-up (median: 8 months) showed death from disease (n = 1), death from a gastrointestinal bleed (n = 1), and a cutaneous metastasis (n = 1). Only two patients are alive with no evidence of disease.

CONCLUSIONS

Our findings outline the morphological spectrum of cytoplasmic change in cutaneous angiosarcoma. Awareness and a high degree of suspicion in the context of tumours affecting sun-damaged skin of the elderly are necessary to direct appropriate immunohistochemical work-up with inclusion of the endothelial cell markers CD31 and ERG.

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.

Clinicopathologic characteristics and outcomes of histiocytic and dendritic cell neoplasms: the moffitt cancer center experience over the last twenty five years

Neoplasms of histiocytic and dendritic cells are rare disorders of the lymph node and soft tissues. Because of this rarity, the corresponding biology, prognosis and terminologies are still being better defined and hence historically, these disorders pose clinical and diagnostic challenges. These disorders include Langerhans cell histiocytosis (LCH), histiocytic sarcoma (HS), follicular dendritic cell sarcoma (FDCS), interdigtating cell sarcoma (IDCS), indeterminate cell sarcoma (INDCS), and fibroblastic reticular cell tumors (FRCT). In order to gain a better understanding of the biology, diagnosis, and treatment in these rare disorders we reviewed our cases of these neoplasms over the last twenty five years and the pertinent literature in each of these rare neoplasms. Cases of histiocytic and dendritic cell neoplasms diagnosed between 1989–2014 were identified using our institutional database. Thirty two cases were included in this analysis and were comprised of the following: Langerhans cell histiocytosis (20/32), histiocytic sarcoma (6/32), follicular dendritic cell sarcoma (2/32), interdigitating dendritic cell sarcoma (2/32), indeterminate dendritic cell sarcoma (1/32), and fibroblastic reticular cell tumor (1/32). Median overall survival was not reached in cases with LCH and showed 52 months in cases with HS, 12 months in cases with FDCS, 58 months in cases with IDCS, 13 months in the case of INDCS, and 51 months in the case of FRCT. The majority of patients had surgical resection as initial treatment (n = 18). Five patients had recurrent disease. We conclude that histiocytic and dendritic cell neoplasms are very rare and perplexing disorders that should be diagnosed with a combination of judicious morphology review and a battery of immunohistochemistry to rule out mimics such as carcinoma, lymphoma, neuroendocrine tumors and to better sub-classify these difficult to diagnose lesions. The mainstay of treatment for localized disease remains surgical resection and the role of adjuvant therapy is unclear. In patients with multiple areas of involvement, treatment at tertiary care centers with multimodality treatment is likely needed. Accurate subset diagnosis will contribute to better data as well as treatment outcomes analysis of these rare disorders of adult patients in the future.

Orbital histiocytic sarcoma in a 2-year-old child

Histiocytic sarcoma (HS) is an exceedingly rare hematologic malignancy that typically presents in the skin, gastrointestinal tract, and lymph nodes. Few cases of HS have been reported in the head and neck. This study describes the case of a 2-year-old girl presenting with 2 weeks of left lower eyelid swelling. Diagnostic testing and biopsy revealed a large inferior orbital mass causing severe bony destruction with extension into the sinuses. Pathologic analysis revealed classic features of HS. To the best of knowledge, no previous case of HS occurring in the orbit of a child has been reported. This study presents an exceedingly rare case of HS in a young child presenting with eyelid swelling. In addition, this case report is in compliance with HIPAA regulations.

Primary endobronchial histiocytic sarcoma in a case of papillary carcinoma thyroid: a complex clinical scenario

Histiocytic sarcoma is a rare malignant neoplasm showing histiocytic differentiation. We document a case of a 55-year-old man presenting with cough and breathlessness following a subtotal thyroidectomy for infiltrating papillary thyroid carcinoma. An endobronchial growth was seen on endoscopy. Histopathologic examination revealed a neoplasm of histiocytic lineage with positivity for leucocyte common antigen, Vimentin, CD68, CD4, and CD45RO. To the best of our knowledge, primary endobronchial histiocytic sarcoma in association with infiltrating papillary thyroid carcinoma has not been reported in the literature so far. Our case emphasizes the importance of clinicopathologic and radiologic correlation in resolving difficult diagnostic dilemmas.

Successful treatment of pediatric histiocytic sarcoma using abbreviated high-risk leukemia chemotherapy

Histiocytic sarcoma (HS) is a malignant tumor composed of proliferating cells of histiocytic origin. True HS is exceedingly rare, particularly in pediatric patients. These tumors are frequently aggressive, and outcome for patients with HS has traditionally been poor. There is currently no consensus on the optimal management of these tumors, with the literature consisting largely of case reports and small case series utilizing a wide variety of therapies. We describe a case of HS in an 8-year-old female who was successfully treated with an abbreviated leukemia chemotherapy regimen.

Viral oncolysis - can insights from measles be transferred to canine distemper virus?

Neoplastic diseases represent one of the most common causes of death among humans and animals. Currently available and applied therapeutic options often remain insufficient and unsatisfactory, therefore new and innovative strategies and approaches are highly needed. Periodically, oncolytic viruses have been in the center of interest since the first anecdotal description of their potential usefulness as an anti-tumor treatment concept. Though first reports referred to an incidental measles virus infection causing tumor regression in a patient suffering from lymphoma several decades ago, no final treatment concept has been developed since then. However, numerous viruses, such as herpes-, adeno- and paramyxoviruses, have been investigated, characterized, and modified with the aim to generate a new anti-cancer treatment option. Among the different viruses, measles virus still represents a highly interesting candidate for such an approach. Numerous different tumors of humans including malignant lymphoma, lung and colorectal adenocarcinoma, mesothelioma, and ovarian cancer, have been studied in vitro and in vivo as potential targets. Moreover, several concepts using different virus preparations are now in clinical trials in humans and may proceed to a new treatment option. Surprisingly, only few studies have investigated viral oncolysis in veterinary medicine. The close relationship between measles virus (MV) and canine distemper virus (CDV), both are morbilliviruses, and the fact that numerous tumors in dogs exhibit similarities to their human counterpart, indicates that both the virus and species dog represent a highly interesting translational model for future research in viral oncolysis. Several recent studies support such an assumption. It is therefore the aim of the present communication to outline the mechanisms of morbillivirus-mediated oncolysis and to stimulate further research in this potentially expanding field of viral oncolysis in a highly suitable translational animal model for the benefit of humans and dogs.

Genetic signature of histiocytic sarcoma revealed by a sleeping beauty transposon genetic screen in mice

Histiocytic sarcoma is a rare, aggressive neoplasm that responds poorly to therapy. Histiocytic sarcoma is thought to arise from macrophage precursor cells via genetic changes that are largely undefined. To improve our understanding of the etiology of histiocytic sarcoma we conducted a forward genetic screen in mice using the Sleeping Beauty transposon as a mutagen to identify genetic drivers of histiocytic sarcoma. Sleeping Beauty mutagenesis was targeted to myeloid lineage cells using the Lysozyme2 promoter. Mice with activated Sleeping Beauty mutagenesis had significantly shortened lifespan and the majority of these mice developed tumors resembling human histiocytic sarcoma. Analysis of transposon insertions identified 27 common insertion sites containing 28 candidate cancer genes. Several of these genes are known drivers of hematological neoplasms, like Raf1, Fli1, and Mitf, while others are well-known cancer genes, including Nf1, Myc, Jak2, and Pten. Importantly, several new potential drivers of histiocytic sarcoma were identified and could serve as targets for therapy for histiocytic sarcoma patients.

Histiocytic sarcoma : an updated literature review based on the 2008 WHO classification

Histiocytic sarcoma (HS) is an extremely rare malignant neoplasm showing morphologic and immunophenotypic evidence of histiocytic differentiation. The vast majority of previously reported HSs are now generally recognized to be misdiagnosed examples of non-Hodgkin lymphomas, predominantly diffuse large B-cell lymphoma or anaplastic large cell lymphoma. The recognition of such tumors parallels the development and widespread use of immunohistochemical techniques, along with the development of molecular genetic methods to detect immunoglobulin (IG) or T-cell receptor (TCR) gene rearrangement. The 2001 World Health Organization (WHO) definition of HS requires the absence of clonal B/T-cell receptor gene rearrangements. However, the 2008 WHO classification no longer strictly requires the absence of clonal immunoglobulin heavy chain (IGH) or TCR gene rearrangement for the diagnosis of HS. Recent studies demonstrated that HSs that occur subsequent to or concurrent with B- or T-lymphoblastic lymphoma/leukemia or mature B-cell neoplasms generally show clonal IgH and/or TCR gene rearrangement. These findings suggest the possibility of transdifferentiation of the two otherwise morphologically and immunohistochemically distinctive neoplasms. In addition, a recent study suggested clonal IG gene rearrangements may be detected at a high frequency in sporadic HS, indicating that a large subset of sporadic HSs may inherit the B-lymphocyte genotype. These findings provide new insights into the pathogenesis of HS, although the etiology of HS is still unknown. HS is a diagnosis of exclusion. It is necessary to rule out other diseases that could be misdiagnosed as HS with extensive immunophenotypical analysis before diagnosing HS.

Atypical fibroxanthoma with pseudoangiomatous features: a histological and immunohistochemical mimic of cutaneous angiosarcoma

Atypical fibroxanthoma and pleomorphic dermal sarcoma may be difficult to separate from cutaneous angiosarcoma. We aim to study the morphological spectrum of pseudoangiomatous features in these tumors and the value of staining for endothelial markers CD31, CD34, FLI1, and ERG. Eleven atypical fibroxanthomas and 3 pleomorphic dermal sarcomas were identified. All tumors arose on sun-damaged skin of elderly men. Atypical fibroxanthomas were nodular and confined to the dermis, whereas pleomorphic dermal sarcoma invaded into underlying fascia. All tumors were composed of pleomorphic epithelioid and spindle cells showing blood-filled spaces and intratumoral hemorrhage. Intracytoplasmic vacuoles (n = 4), hemosiderin deposition (n = 2), and keloidal stromal change (n = 1) were also noted. Immunohistochemically, CD31 was expressed in 43% of cases, FLI1 in 79% and smooth muscle actin in 50%. Staining for CD34, ERG, S100, HMB-45, desmin, p63 and cytokeratins was negative. Follow up (median, 43.1 months; range 1-100), available for 10 patients, showed no adverse outcome. Pseudoangiomatous features and aberrant expression of CD31 and FLI1 in atypical fibroxanthoma and pleomorphic dermal sarcoma may lead to an erroneous diagnosis of cutaneous angiosarcoma. Negativity for CD34 and ERG, in particular, is a reliable differentiating feature in this setting.

Primary leptomeningeal histiocytic sarcoma in a patient with a good outcome: a case report and review of the literature

Introduction

Histiocytic sarcoma is a rare neoplasm with few cases reported in the literature of which some were diagnosed in animals. This neoplasm arises from abnormal reticuloendothelial system cell proliferation of histiocytes and has an aggressive behavior especially if located in the central nervous system. We present the first case of a patient with histiocytic sarcoma that involved the meninges and had a good course after multidisciplinary treatment.

Case presentation

Our patient was a 41-year-old Caucasian woman with no previous history of disease who started with systemic symptoms such as headache and chills. Magnetic resonance imaging with gadolinium contrast of the brain suggested a mass 1.5×2cm in diameter in the temporal lobe with a non-uniform vasogenic edema. This lesion was implanted in the meninges and surgery was the first treatment. The histological findings revealed a histiocytic sarcoma. The patient received concomitant chemoradiotherapy after surgery with good tolerance and currently lives without disease.

Conclusion

Although histiocytic sarcomas in the brain present an unusual location and have a poorer prognosis, we have identified the first primary leptomeningeal histiocytic sarcoma with a disease-free survival greater than 3 years following multidisciplinary treatment with surgery and chemotherapy and radiotherapy.

Laparoscopic splenectomy for histiocytic sarcoma of the spleen

Primary histiocytic sarcoma of the spleen is a rare but potentially lethal condition. It can remain asymptomatic or only mildly symptomatic for a long time. An 81-year-old woman presented with an extremely enlarged spleen. She suffered from progressive anemia and required a red blood cell transfusion once a month. Although computed tomography, ultrasonography, and magnetic resonance imaging were performed for diagnosis, a confirmed diagnosis was not obtained. Her enlarged spleen compressed her stomach, and she suffered from gastritis and a sense of gastric fullness just after meals. She underwent laparoscopic splenectomy for therapeutic and diagnostic purposes. Her post-operative course was uneventful. After surgery, her red blood cell and platelet counts increased markedly. The tumor was diagnosed as splenic histiocytic sarcoma. Post-surgical chemotherapy was not performed, and the patient died of liver failure due to liver metastasis 5 mo after surgery. Laparoscopic splenectomy is minimally invasive and useful for the relief of symptoms related to hematological disorders. However, in cases of an enlarged spleen, optimal views and working space are limited. In such cases, splenic artery ligation can markedly reduce the size of the spleen, thus facilitating the procedure. The case reported herein suggests that laparoscopic splenectomy may be useful for the treatment of splenic malignancy.

The utility of balloon enteroscopy in the diagnosis of histiocytic sarcoma of the small intestine: a case report

The diagnosis of the rare neoplasm histiocytic sarcoma (HS) relies on morphology and the presence of immunophenotypic features of histiocytic lineage. More than 57 cases, including 16 cases involving the gastrointestinal (GI) tract, have been described since the World Health Organization issued its classification system for tumors of hematopoietic and lymphoid tissue in 2001. HS is often diagnosed in its late stages, at which point the prognosis is poor. Only a small proportion of these patients can undergo surgical resection with curative intent. The present report describes how HS can be diagnosed at a stage of favorable prognosis using balloon enteroscopy (BE), thereby enabling surgical resection before the development of metastases. This strategy is reviewed in the setting of a patient with jejunal HS, followed by a discussion of data from 16 other reported cases of GI HS.

Unusual cutaneous Langerhans cell sarcoma without extracutaneous involvement

Abstract

Langerhans cell sarcoma (LCS) typically presents as cytologic atypia and clinical aggressiveness and may involve multiple organs during the progression of the disease. Primary skin LCS without any extra-cutaneous site association is extremely rare and only a few such cases have been described in the literature. We present a case of unusual primary LCS in skin occurring in a middle-aged male patient. Physical examination revealed a large ulcerated cutaneous lesion and a smaller nodular lesion were located in the skin of the extensor side of his right knee. There was no regional lymph node or any other extra-cutaneous organ involvement. Histologically, typical large and pleomorphological tumor cells with epithelioid appearance and significantly malignant cytological features were observed to infiltrate in dermis and subcutaneous tissue. By immunohistochemistry, the tumor cells were positive for CD1a, S-100 protein and largerin strongly and diffusely. However, these cells were negative for CD3, CD20, CD21, pan-cytokeratin, HMB-45, Melan-A, and MPO. A diagnosis of primary cutaneous LCS was made. The patient received systemic chemotherapy of CHOP regimen, and was on a regular follow-up period for 12 months. There was no sign of relapse of tumor or any other extra-cutaneous organ involvement by whole body positron emission tomography/computed tomography (PET/CT) study. Because LCS is a high-grade malignancy with poor prognosis, it suggests that strict histological analysis and thorough radiographic examination are necessary for accurately diagnosing this tumor even if cutaneous involvement presented only.

Virtual slides

http://www.diagnosticpathology.diagnomx.eu/vs/6527428618381393

Unusual presentation of a rare cancer: histiocytic sarcoma in the brain 16 years after treatment for acute lymphoblastic leukemia

Histiocytic sarcoma (HS) is a very rare hematopoietic neoplasm that has been reported in association with other hematological malignancies. Presentation of HS in the central nervous system is even less common. Diagnosis of HS requires the presence of histiocytic markers and the systematic exclusion of markers of other cell lineages. Primary HS central nervous system tumors are aggressive and generally have poor outcomes. There are no standard treatment guidelines due to lack of clinical trials and a limited number of case reports. Here we present a unique case with two primary histiocytic lesions in the brain, refractory to systemic and radiation therapies, that developed after being treated for T-cell acute lymphoblastic leukemia 16 years prior.

Primary histiocytic sarcoma of the stomach: A case report with imaging findings

Histiocytic sarcoma (HS) is a rare malignant neoplasm that originates from a histiocytic hematopoietic lineage characterized by histiocytic differentiation and its corresponding immunophenotypic features. We herein reported a case of primary HS of the stomach which was confirmed through histopathologic examination and immunohistochemical staining. A 52-year-old woman presented with progressive difficulty in feeding and dull pain in the epigastric region. Gastroscopy, endoscopic ultrasonography, double contrast examination, and computed tomography revealed a mass located on the posterior wall of fundus and lesser curvature of the stomach. Microscopically, the cytoplasm of the tumor cells was abundant and eosinophilic. Immunohistochemical staining revealed that the tumor cells were positive for CD45RO and CD68. It is difficult to differentiate HS of stomach from other gastric malignancies by radiological evaluation alone. However, HS may be considered when a protruding and ulcerated mass in stomach shows heterogeneous hypervascular features. To the best of our knowledge, this is the first report in English language literature that emphasizes the imaging findings of human gastric HS.

Incidence, survival and prevalence of myeloid malignancies in Europe

BACKGROUND

The Surveillance of Rare Cancers in Europe (RARECARE) project aims at increasing knowledge of rare cancers in Europe. This manuscript describes the epidemiology of myeloid malignancies (MMs), taking into account the morphological characterisation of these tumours.

METHODS

We used data gathered by RARECARE on cancer patients diagnosed from 1995 to 2002 and archived in 64 European population-based cancer registries, followed up to 31st December 2003 or later.

RESULTS

The overall annual crude incidence of MMs was 8.6 per 100,000. Acute myeloid leukaemia (AML) and myeloproliferative neoplasms (MPN) were most common, with incidence rates of 3.7 and 3.1 per 100,000 year respectively, followed by 1.8 for myelodysplastic syndromes (MDS) and myelodysplastic/myeloproliferative neoplasms (MD/MPN) and 0.1 for histiocytic and dendritic cell neoplasms (HDCN). The 5-year relative survival rate ranged from 18% for chronic myelomonocytic leukaemia, 19% for AML, 29% for MDS and 44% for chronic myeloid leukaemia to relatively favourable rates for MPN (62%) and HDCN (83%). Total number of new cases of MMs in the EU27 is estimated at 43,000 annually, total number of prevalent cases (1st January 2008) at 189,000 cases.

CONCLUSION

MMs form a large variety of rare entities with specific characteristics. Collection of detailed information (immunophenotype, genetic abnormalities, molecular data and clinical data) and an up-to-date classification system is essential for their surveillance, especially now that more and more targeted therapies are being introduced.

Primary splenic histiocytic sarcoma complicated with prolonged idiopathic thrombocytopenia and secondary bone marrow involvement: a unique surgical case presenting with splenomegaly but non-nodular lesions

Abstract

A 67-year-old Japanese female was followed up due to prolonged idiopathic thrombocytopenia with non-response to steroid therapy for 4 years, but recent progressive pancytopenia, hypo-albuminemia, and hypo-γ-globulinemia were presented. An abdominal CT scan revealed heterogeneously enhanced splenomegaly without any nodular lesions. A splenectomy was performed, and gross examination showed markedly hyperemic red pulp, weighing 760 g, accompanied by multiple foci of peripheral anemic infarction. Surprisingly, microscopic findings exhibited a diffuse proliferation of medium-sized to large tumor cells having pleomorphic nuclei, prominent nucleoli, and abundant eosinophilic cytoplasm, predominantly within the sinuses and cords of the red pulp, which occasionally displayed conspicuous hemophagocytosis and vascular permeation. In immunohistochemistry, these atypical cells were specifically positive for CD68 (KP-1), CD163, and lysozyme, which was consistent with histiocytic sarcoma (HS) of the spleen. Subsequently, section from the aspiration of bone marrow showed infiltration of the neoplastic cells associated with erythrophagocytosis 2 months after the operation, but never before it. Therefore, primary splenic HS presenting with secondary bone marrow involvement was conclusively diagnosed. Since early diagnosis and treatment are necessary for the HS patients with poor outcomes, splenic HS should be considered as a differential diagnosis in cases with chronic thrombocytopenia and splenomegaly.

Virtual slides

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1009474924812827

[Unusual lung localization of histiocytic sarcoma]

Histiocytic sarcoma, proliferation araising from immunoregulatory effector system cells, is a very rare and recently recognised tumor. Diagnosis is based on immunohistochemistry and molecular genetic techniques, which allow to distinguish histiocytic sarcoma from lymphocytic proliferation, such as non-Hodgkin's. We report this rare case of multivisceral histiocytic sarcoma revealed by lung localization and for which the evolution was fatal.

Gastrointestinal lymphomas: Morphology, immunophenotype and molecular features

Primary gastrointestinal lymphoma comprises 10-15% of all non-Hodgkin lymphomas and encompasses 30-40% of the total extranodal lymphomas. Approximately 60-75% of cases occur in the stomach, and then the small bowel, ileum, cecum, colon and rectum. Lymphoid neoplasms may consist of mature B, T and less commonly extranodal NK/T cells. Of these, the two most frequently encountered histologic subtypes are extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma), where Helicobacter pylori infection is implicated in a number of cases, and diffuse large B cell lymphoma. Several B cell lymphomas are associated with chromosomal aberrations. Enteropathy-associated T cell lymphoma, type I in particular, usually arises in a background of celiac disease. T cell gene rearrangement confirms clonality. NK/T cell neoplasms are invariably associated with Epstein-Barr virus infection and are often aggressive; thus, differentiation from a benign NK-cell enteropathy is paramount. Although incidence of other hematopoietic malignancies in the gastrointestinal tract such as plasma cell myeloma associated with amyloidosis, plasmablastic lymphoma, Hodgkin disease, histiocytic sarcoma and mast cell sarcoma is extremely rare, these entities have been documented, with the latter two demonstrating aggressive clinical behavior. Endoscopic ultrasonography is an important adjunct in disease staging and follow-up. Conservative antibiotic treatment of stage I MALT lymphomas with associated Helicobacter pylori infection achieves good clinical outcome with high remission rate. Chemotherapy, radiation and rarely surgery are reserved for advanced diseases or cases resistant to conservative therapy and those not associated with Helicobacter pylori infection.

Gastrointestinal lymphomas: Morphology, immunophenotype and molecular features

Primary gastrointestinal lymphoma comprises 10-15% of all non-Hodgkin lymphomas and encompasses 30-40% of the total extranodal lymphomas. Approximately 60-75% of cases occur in the stomach, and then the small bowel, ileum, cecum, colon and rectum. Lymphoid neoplasms may consist of mature B, T and less commonly extranodal NK/T cells. Of these, the two most frequently encountered histologic subtypes are extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma), where Helicobacter pylori infection is implicated in a number of cases, and diffuse large B cell lymphoma. Several B cell lymphomas are associated with chromosomal aberrations. Enteropathy-associated T cell lymphoma, type I in particular, usually arises in a background of celiac disease. T cell gene rearrangement confirms clonality. NK/T cell neoplasms are invariably associated with Epstein-Barr virus infection and are often aggressive; thus, differentiation from a benign NK-cell enteropathy is paramount. Although incidence of other hematopoietic malignancies in the gastrointestinal tract such as plasma cell myeloma associated with amyloidosis, plasmablastic lymphoma, Hodgkin disease, histiocytic sarcoma and mast cell sarcoma is extremely rare, these entities have been documented, with the latter two demonstrating aggressive clinical behavior. Endoscopic ultrasonography is an important adjunct in disease staging and follow-up. Conservative antibiotic treatment of stage I MALT lymphomas with associated Helicobacter pylori infection achieves good clinical outcome with high remission rate. Chemotherapy, radiation and rarely surgery are reserved for advanced diseases or cases resistant to conservative therapy and those not associated with Helicobacter pylori infection.