Histiocytic Sarcoma Associated With Idiopathic Myelofibrosis

Histiocytic Sarcoma Secondary to Gastrointestinal Stromal Tumors: A Literature Review

Histiocytic sarcoma (HS) is a rare tumor that may result from the transdifferentiation of preexisting hematolymphoid neoplasms in a subset of patients. There are instances of correlation or concurrence between HS and a number of cancers, particularly B-cell-associated hematopoietic tumors. Only three cases of HS occurring subsequent to or concurrently with gastrointestinal stromal tumors (GIST) have been recorded. Our main objective was to give an overview of demographics, clinical signs and symptoms, histopathological findings, and immunohistochemical and molecular analysis when HS develops secondary to or concurrently with GIST. A search of PubMed, Google Scholar, and ScienceDirect was undertaken using Medical Subject Headings (MeSH) keywords. According to the findings of our review, there were two males (66.6%) and one female (33.3%). The average age of patients at presentation was 59.6 years. On the immunohistochemistry, three patients were positive for cluster of differentiation (CD) 68 (100%), two patients were positive for CD 163 (67%), one patient was positive for leukocyte common antigen (LCA) (33%), and only one patient was positive for CD 4, CD 10, CD 31, CD 45, human leukocyte antigen (HLA)-DR, lysozyme, and vimentin (33%). On molecular investigation, the gastric mass of only one patient (33.33%) contained a KIT mutation on exon 11. Emperipolesis was observed in one patient (33.33%) on histological examination. Our study provides an important overview of the available literature and gives insight into important diagnostic markers of HS when it occurs secondary to or concurrently with GIST.

A Rare Case of Histiocytic Sarcoma Secondary to Gastrointestinal Stromal Tumor in the Stomach: Transdifferentiation or Synchronicity?

Histiocytic sarcoma is a rare malignant histiocytic neoplasm composed of cells with morphologic and immunophenotypic features of mature tissue histiocytes. It occurs anywhere in the body and behaves aggressively. However, its etiology is unknown. Here, we report a 68-year-old female who developed histiocytic sarcoma following chemotherapy with imatinib (Gleevec) for gastrointestinal stromal tumor. Possible mechanisms of transdifferentiation from gastrointestinal stromal tumor to histiocytic sarcoma are discussed based on the features of our case and other two similar cases in the literature.

Morphological Distinction of Histiocytic Sarcoma from Other Tumor Types in Bernese Mountain Dogs and Flatcoated Retrievers

BACKGROUND/AIM

Histiocytic sarcoma (HS) represents a group of malignant canine tumors to which Bernese Mountain Dogs (BMD) and Flatcoated Retrievers (FCR) are predisposed. The differential diagnosis for HS is broad, encompassing round cell tumors, sarcomas and other histiocytic diseases. The aim of this study was to establish morphological and immunohistochemical criteria for routine use on formalin-fixed, paraffin-embedded samples and cytological smears for the recognition and differentiation of canine HS and its subtypes.

MATERIALS AND METHODS

Retrospectively, tumor sections were reviewed from 449 BMD and 380 FCR with confirmed or suspected HS, other histiocytic conditions, or a disease of the differential diagnosis of HS.

RESULTS

In a large proportion of cases, 47.5% for histology and for 46.3% cytology, the initial diagnosis was changed after the revision process. A large variation in morphological features of HS was observed in this study, making the existence of several subtypes in dogs also very likely. Furthermore, the different percentage of morphological features between BMD and FCR indicates the different mixture of cell type origins resulting possibly from genetic or environmental differences at the onset of HS in those breeds.

CONCLUSION

This study stresses the value of a strictly applied and standardized scoring system for microscopic evaluation of tumor sections and smears, and the implementation of review and revision of pathological diagnoses.

JAK2-mutated Langerhans cell histiocytosis associated with primary myelofibrosis treated with ruxolitinib

The pathogenesis and cellular origin of Langerhans cell histiocytosis (LCH) are debated. Recently, mutations on MAPK and PI3K pathways have been linked to disrupted cell proliferation in LCH. Janus Kinase 2 (JAK2) mutations play the same role in Philadelphia-negative chronic myeloproliferative neoplasms. We describe the case of a patient affected by JAK2-positive primary myelofibrosis (PMF) who developed a clonally related LCH while in treatment with ruxolitinib. JAK inhibitors are well known to affect function and differentiation of different hematological lineages, including mononuclear phagocytes precursors. Nevertheless, the literature describes cases of LCH clonally associated with non-LCH hematological neoplasm, suggesting how multilinear myeloid neoplasms may arise from bone marrow. Hence, we briefly discuss the possible pathogenic roles of genetic mutations and JAK inhibition therapy in the pathogenesis of LCH and associated neoplasms.

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.

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.

Histiocytic sarcoma involving lymph nodes: imaging appearance on gallium-67 and F-18 FDG PET/CT

This report of an 82-year-old man who presented with a 3-week history of an enlarging left axillary mass and mild fevers, highlights the usefulness of both gallium-67 and F-18 FDG PET/CT imaging in the staging of histiocytic sarcoma. While PET/CT was superior in determining the extent of the disease, gallium can be used to help stage the disease in centers where PET/CT is not available.

[A case of extranodal histiocytic sarcoma of stomach mimicking gastric adenocarcinoma]

Histiocytic sarcoma is a rare malignant neoplasm that originates from a histiocytic hematopoietic lineage characterized by histiocytic differentiation and its corresponding immunophenotypic features. Patients with histiocytic sarcoma usually have a poor prognosis due to its aggressive clinical behavior. Here we report a rare case of extranodal histiocytic sarcoma of the stomach which was confirmed through immunohistochemical staining. A 71-year- old man was presented with epigastric pain. Gastroscopy, abdominal CT, and EUS revealed a mass located on the posterior wall of upper body and fundus of the stomach. Grossly, grayish white solid masses were seen extending down to the submucosal layer. Microscopically, the tumor cells had eosinophilic cytoplasm, abundant vacuole, and mitosis. Immunohistochemical staining revealed that the tumor cells were positive for LCA, CD68, and lysozyme. Early detection and accurate diagnosis of this rare neoplasm is important because it can make a great difference in prognostic outcomes. To make an accurate and definitive diagnosis, immunohistochemical staining is essential in the confirmation of histiocytic origin.

Histiocytic sarcoma and underlying chronic myelomonocytic leukemia: a proposal for the developmental classification of histiocytic sarcoma

A 70-year-old male was admitted because of back pain due to peri-vertebral tumors. The histologic picture of a needle-biopsied tumor specimen showed pleomorphic large cell infiltration into the collagen fibers. On immunohistochemistry, these abnormal cells were positive for CD68, CD163 and lysozyme but negative for CD1a, 21, 30, and S100. Flow cytometric analysis also demonstrated that these cells were positive for CD13, 14, 38, 45, 56, and HLA-DR. A bone marrow aspirate showed the marked infiltration of abnormal large cells with the same surface antigens as described above. A diagnosis of HS was made. He showed monocytosis in the peripheral blood of more than 1.0 x 10(9)/L from presentation. The karyotype of bone marrow cells was 46,XY,+8. Fluorescent in situ hybridization (FISH) analysis with a probe for chromosome no. 8 showed that all these monocytes carried +8, indicating that he had another disorder of chronic myelomonocytic leukemia (CMML). FISH analysis with a probe for chromosome no. 12 demonstrated that the abnormal large cells in the bone marrow were all tetraploid, while analysis with the chromosome no. 8 probe showed more than 8 signals per cell, indicating that HS cells carried octasomy to decasomy of chromosome no. 8. These findings strongly suggest that HS in the present patient originated from underlying CMML.

A case of histiocytic sarcoma presenting with primary bone marrow involvement

Histiocytic sarcoma (HS) is a very rare neoplasm that often shows an aggressive clinical course and systemic symptoms, such as fever, weight loss, adenopathy, hepatosplenomegaly and pancytopenia. It may present as localized or disseminated disease. We describe here a 63-yr-old male who manifested systemic symptoms, including fever, weight loss and generalized weakness. Abdominal and chest computed tomography failed to show specific findings, but there was suspicion of multiple bony changes at the lumbar spine. Fusion whole body positron emission tomography, bone scan and lumbar spine magnetic resonance imaging showed multiple bone lesions, suggesting a malignancy involving the bone marrow (BM). Several BM and bone biopsies were inconclusive for diagnosis. Necropsy showed replacement of the BM by a diffuse proliferation of neoplastic cells with markedly increased cellularity (95%). The neoplastic cells were positive for lysozyme and CD68, but negative for T- and B-cell lineage markers, and megakaryocytic, epithelial, muscular and melanocytic markers. Morphologic findings also distinguished it from other dendritic cell neoplasms.