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

Pancreatic follicular dendritic cell sarcoma: a rare case report and systematic literature review of 7 cases

INTRODUCTION

Pancreatic follicular dendritic cell sarcoma (FDCS) is an exceptionally rare and low-to-moderate malignancy, with only seven reported cases to date. Clinical diagnosis of FDCS is challenging due to the lack of distinct biological and radiographic features.

CASE PRESENTATION

A 67-year-old woman presented to the hospital with a 4-day history of severe abdominal pain. Imaging studies (CT and MRI) revealed a large cystic mass located at the tail of the pancreas, which was suspected to be myeloid sarcoma (MS) based on EUS and CT-guided pancreatic puncture. Postoperative pathology and immunohistochemistry confirmed the diagnosis of pancreatic FDCS. After the diagnosis was confirmed, the patient received postoperative chemotherapy with the CHOP regimen. At 11 months of follow-up, there was no evidence of recurrence. Seven published cases have been reviewed to comprehensively summarize the clinical characteristics, diagnosis, and treatment options of FDCS.

CONCLUSION

While imaging can be useful in detecting pancreatic FDCS, it should be interpreted with caution as it can be challenging to differentiate from other pancreatic tumors. Pathology and immunohistochemistry are considered the gold standard for diagnosis, with CD21, CD23, and CD35 being specific tumor cell markers. However, preoperative diagnosis of pancreatic FDCS remains difficult, and the pancreatic puncture may further increase the risk of misdiagnosis. The disease is highly prone to recurrence and metastasis, and surgery is the preferred method for both diagnosis and treatment of localized disease.

Whole exome and transcriptome analysis revealed the activation of ERK and Akt signaling pathway in canine histiocytic sarcoma

Histiocytic sarcoma (HS) is an incurable aggressive tumor, and no consensus has been made on the treatment due to its rare occurrence. Since dogs spontaneously develop the disease and several cell lines are available, they have been advocated as translational animal models. In the present study, therefore, we explored gene mutations and aberrant molecular pathways in canine HS by next generation sequencing to identify molecular targets for treatment. Whole exome sequencing and RNA-sequencing revealed gene mutations related to receptor tyrosine kinase pathways and activation of ERK1/2, PI3K-AKT, and STAT3 pathways. Analysis by quantitative PCR and immunohistochemistry revealed that fibroblast growth factor receptor 1 (FGFR1) is over-expressed. Moreover, activation of ERK and Akt signaling were confirmed in all HS cell lines, and FGFR1 inhibitors showed dose-dependent growth inhibitory effects in two of the twelve canine HS cell lines. The findings obtained in the present study indicated that ERK and Akt signaling were activated in canine HS and drugs targeting FGFR1 might be effective in part of the cases. The present study provides translational evidence that leads to establishment of novel therapeutic strategies targeting ERK and Akt signaling in HS patients.

An Overview of Epithelial-to-Mesenchymal Transition and Mesenchymal-to-Epithelial Transition in Canine Tumors: How Far Have We Come?

Historically, pre-clinical and clinical studies in human medicine have provided new insights, pushing forward the contemporary knowledge. The new results represented a motivation for investigators in specific fields of veterinary medicine, who addressed the same research topics from different perspectives in studies based on experimental and spontaneous animal disease models. The study of different pheno-genotypic contexts contributes to the confirmation of translational models of pathologic mechanisms. This review provides an overview of EMT and MET processes in both human and canine species. While human medicine rapidly advances, having a large amount of information available, veterinary medicine is not at the same level. This situation should provide motivation for the veterinary medicine research field, to apply the knowledge on humans to research in pets. By merging the knowledge of these two disciplines, better and faster results can be achieved, thus improving human and canine health.

Pancreatic follicular dendritic cell sarcoma: one case report and literature review

Pancreatic follicular dendritic cell sarcoma (FDCS) is a rare neoplasm with unclear pathological characteristics. In this study, we report one case of pancreatic FDCS and review published cases to summarize the characteristics and treatment of pancreatic FDCS. A man in his early 30 s was admitted for jaundice, abdominal fullness, and weight loss for 15 days. Computed tomography revealed a large capsule solid mass in the pancreatic head together with a dilated bile duct and enlarged retroperitoneal lymph nodes. Serum biochemistry revealed high total bilirubin levels (313.9 μmol/L) and normal tumor marker levels. Pancreatoduodenectomy was performed, but no chemotherapy was administrated at the patient's behest. The pathologic diagnosis was pancreatic FDCS infiltrating the duodenal seromuscular layer and common bile duct. The patient presented with liver metastasis 3 months after surgery and died 8 months after surgery from multiorgan failure. Pancreatic FDCS is a rare disease with high invasiveness. Our previous case exhibited paraneoplastic syndrome together with this disease, and further investigation is needed to confirm whether paraneoplastic syndrome is a typical syndrome of pancreatic FDCS.

Angioimmunoblastic T-cell lymphoma with extensive follicular dendritic cell and fibroblastic reticular cell network proliferation mimicking follicular dendritic cell sarcoma: A case report with pathologic, immunophenotypic, and molecular findings

Angioimmunoblastic T-cell lymphoma (AITL) is a common type of nodal peripheral T-cell lymphoma, which always presents with extensive follicular dendritic cell (FDC) meshwork. Here, we report a case of AITL combined with extensive spindle cell meshwork. Spindle cells occupied were positive for the FDC markers CD21, CD23, and CD35. Furthermore, some cells were positive for desmin and smooth muscle actin (SMA), suggesting the differentiation of fibroblastic reticular cell (FRC). Interestingly, the proliferation of spindle cells was so extensive that was easily misdiagnosed as FDC sarcoma (FDCS). Next-generation sequencing showed that the common mutations reported in AITL, including RHOA, TET2, and IDH2, were also detected in this case, while the genes that are recurrently mutated in FDCS were not detected. Regrettably, the patient died 19 months later. Overall, we highlight the unusual morphologic features in an AITL patient with extensive FDC and FRC network that may be misdiagnosed as FDCS, and careful morphological observation and immunochemical and molecular examinations are crucial for an accurate diagnosis.

Doxorubicin for treatment of histiocytic sarcoma in dogs: 31 cases (2003-2017)

OBJECTIVE

To evaluate the efficacy of doxorubicin for treatment of histiocytic sarcoma (HS) in dogs, whether administered as the sole treatment or as an adjunct to surgery or radiation therapy.

ANIMALS

31 client-owned dogs with localized or disseminated HS examined between 2003 and 2017.

PROCEDURES

Medical records were reviewed retrospectively, and data were collected. The Kaplan-Meier method was used to estimate time-to-progression from the date of first doxorubicin administration and survival time from initial diagnosis. Factors that could be associated with poorer outcomes with doxorubicin treatment were analyzed with log-rank tests.

RESULTS

The objective response rate (ORR) was 26%. When stratified by disease status, dogs with localized and disseminated forms experienced 43% and 21% ORRs, respectively. Median time to progression after initiating doxorubicin treatment (n = 30 dogs) was 42 days. Median survival time from initial diagnosis to death (n = 29 dogs) was 169 days. Complete responses were obtained in only 2 dogs that had localized disease and received multimodality therapy.

CLINICAL RELEVANCE

Benefits of doxorubicin administration in canine HS are modest, with a limited ORR and delay in tumor progression, and are comparable to effects attained with other single-agent regimens.

A case of primary histiocytic sarcoma arising from a neck lymph node

Histiocytic sarcoma (HS) is an aggressive and rare hematological malignancy. Its treatment has not been established, and most patients die within 2 years of diagnosis. Resection can provide a favorable prognosis for solitary lesions. We present the case of an 80-year-old Japanese man with HS. He presented a history of a slow-growing painless mass in the lower part of his right jaw. Ultrasonography showed a swollen lymph node in the vicinity of the right submandibular gland. Contrast-enhanced computed tomography revealed a heterogeneous, low-contrast mass on the right of the neck. Magnetic resonance imaging revealed a heterogeneously enhanced mass in gadolinium-enhanced T1-weighted images. The fine needle biopsy showed spindle-shaped cells and HS was suspected. Fluorodeoxyglucose positron emission tomography revealed uptake by the tumor alone. The patient underwent right upper neck dissection and resection of the submandibular salivary glands. No postoperative adjuvant treatment was administered, but 2-year survival was achieved. Histopathological examination showed proliferation of large, pleomorphic atypical cells without differentiation into lymphocytes, which proved their differentiation into histiocytes. A bone marrow biopsy showed no evidence of monocytic leukemia. Thus, a diagnosis of HS was made. With local treatment alone, our patient achieved long-term survival, maintaining his quality of life.

Blastic Indeterminate Dendritic Cell Tumor Associated With Chronic Myelomonocytic Leukemia

ABSTRACT

Indeterminate dendritic cell tumor (IDCT) is an exceedingly rare neoplasm that can be associated with hematopoietic malignancies. We report a case of multifocal cutaneous blastic indeterminate dendritic cell tumor (BIDCT) in a 75-year-old man with chronic myelomonocytic leukemia showing blastic histiocytoid morphology, positivity for CD1a and S100, and no expression of langerin. We present a literature review on the 11 reported cases of IDCTs/BIDCTs associated with chronic myelomonocytic leukemia (CMML), including this case. The clinicopathological characteristics have been summarized. The IDCT and CMML cells are clonally related in 4 tested cases. Patients with IDCT/BIDCT associated with CMML seem to have worse clinical outcomes compared with patients with IDCT not associated with CMML.

Case Report: Eighteen Month Relapse- Free Survival Following Radical Multidisciplinary Oncological Treatment in a 68-Year-Old Male Patient With Histiocytic Sarcoma

Introduction

Histiocytic Sarcoma (HS) is a rare and aggressive malignancy, and patients can present with rapid tumor growth and invasion. The optimal diagnostic and therapeutic management is unknown since only a few cases have been published. Here we report a patient with histiocytic sarcoma of the right groin.

Case

A 68 year-old male patient presented to our hospital with suspicion of a superinfected atheroma of the right groin. Computed tomography showed an abdominal tumor of unknown entity. Detailed assessment including immunohistochemically evaluation of biopsy material confirmed HS. The patient underwent radical tumor resection including compartment-resection of the right thigh. During five additional cycles of chemotherapy over a period of 1.5 years he remained relapse-free.

Summary

Diagnostic work up and treatment of HS is challenging, as there is a paucity of clinical reports and lack of standard guidelines for care. In the present case report, aggressive multidisciplinary treatment resulted in good clinical outcome, however, further studies evaluating this approach in similar patients are needed.

Histiocytic sarcoma arising from a lymph node: a diagnostic conundrum

Histiocytic Sarcoma (HS) is extremely rare, with only a few hundred cases reported in the literature. The majority of patients present with symptoms due to unifocal or multifocal extra-nodal disease. Less than 20% of these cases show solitary involvement of a lymph node. We report a case of a solitary HS in a 53-year-old woman presenting with a 2.7-cm right groin mass arising from an inguinal lymph node. The initial cytologic examination of the tissue showed a high-grade spindle-shaped morphology with high-grade mitotic activity. A high-grade sarcoma was initially considered considering the absence of normal lymphoid aggregate and the presence of high-grade cytologic features in the cells. To evaluate the tumor in its entirety, the mass was surgically excised. A histological examination of the tumor showed focal rimming of the lymphoid tissue at the periphery and a centrally located stellate necrotic focus. The tumor cells had an epithelioid to spindle cell morphology along with large uniform nuclei and prominent nucleoli. A high mitotic index was present. Immunohistochemistry (IHC) stains showed strong positivity for CD68, CD163, and Vimentin, and were weakly positive for SMA and CD45. Based on the histologic and clinical examination, a diagnosis of HS was made. Multiple malignancies can mimic HS histopathology and the rarity of this tumor makes the diagnosis more challenging. No fine-needle aspiration (FNA) criteria for its diagnosis have been recognized. Herein, we report a rare case of an isolated HS involving a lymph node which resembled high-grade sarcoma on the FNA biopsy to raise awareness among our surgical pathologist colleagues.

Descriptive Analysis of Histiocytic and Dendritic Cell Neoplasms: A Single-Institution Experience

PURPOSE

Histiocytic and dendritic cell neoplasms are rare hematologic tumors. This study aimed to describe the epidemiologic features of the entire spectrum of histiocytic and dendritic cell neoplasms, including clinicopathological variables and patient outcomes.

MATERIALS AND METHODS

We comprehensively reviewed 274 patients who were diagnosed with histiocytic and dendritic neoplasms at Severance Hospital, Seoul, South Korea between 1995 and 2018.

RESULTS

The most common neoplasm was Langerhans cell histiocytosis (LCH), followed by dermal xanthogranuloma. Among non-LCH sarcomas, histiocytic sarcoma (HS) showed a relatively high prevalence, followed by follicular dendritic cell sarcoma (FDCS). Disseminated juvenile xanthogranuloma (DJG), Erdheim-Chester disease (ECD), indeterminate dendritic cell tumor (IDCT), and interdigitating dendritic cell sarcoma (IDCS) rarely occurred. Generally, these tumors presented in childhood, although the non-LCH sarcoma (HS/FDCS/IDCS/IDCT) group of tumors and ECD occurred in late adulthood. Multiorgan involvement and advanced Ann-Arbor stage, as well as recurrence and death of disease, were not uncommon. The non-LCH sarcoma group had the worst overall survival, compared to the DJG, ECD, and LCH groups.

CONCLUSION

Our findings indicate that histiocytic and dendritic cell neoplasms exhibit heterogeneous epidemiologic characteristics and that some patients may have unfavorable outcomes, especially those with non-LCH sarcoma.

Primary Histiocytic Sarcoma in Adult Polycystic Kidney Disease: Case Report and Review of Literature

Genetically driven tissue destruction followed by remodeling in adult polycystic kidney disease (APKD) raises the possibility of malignant transformation. Renal cell carcinoma (RCC) associated with APKD has been frequently reported in the literature; however, only a few cases of nonepithelial neoplasms arising in APKD have been described so far. Histiocytic sarcoma (HS) is a lymphohematopoietic malignant neoplasm that accounts for less than 1% of hematologic malignancies. In this article, we describe a case of primary HS occurring in a 61-year-old man with end-stage renal disease secondary to APKD. This is the first reported case of primary HS in the setting of APKD. The aberrant h-caldesmon expression seen in this case is another novel finding that has previously not been described. This case highlights the importance of morphology in guiding diagnostic workup and reiterates the necessity of maintaining a high index of suspicion for neoplastic entities in APKD.

Interdigitating dendritic cell sarcoma of the spleen with hepatic failure after chemotherapy: A case report

RATIONALE

Interdigitating dendritic cell sarcoma (IDCS) is an extremely rare disease originating from dendritic cells (DCs). There are few cases report interdigitating dendritic cell sarcoma of spleen along with their pathological characteristics and treatment.

PATIENT CONCERNS

Here we report a case of IDCS in 53-year-old female who presented spleen enlargement and thrombocytopenia.

DIAGNOSES

The patient underwent surgical resection of spleen, and the pathology confirmed IDCS.

INTERVENTIONS

She received surgical resection of spleen and one cycle of chemotherapy (ABVD with ifosfamide and oxaliplatin) after surgery.

OUTCOMES

She died of severe hepatic failure caused by chemotherapy.

DISCUSSION

IDCS is a rare disease with insufficient treatment guidelines. We adopted chemotherapy of ABVD with ifosfamide and oxaliplatin which showed no improvement but led to life-threatening liver damage.

Genome-wide DNA copy number analysis and targeted transcriptional analysis of canine histiocytic malignancies identifies diagnostic signatures and highlights disruption of spindle assembly complex

Canine histiocytic malignancies (HM) are rare across the general dog population, but overrepresented in certain breeds, such as Bernese mountain dog and flat-coated retriever. Accurate diagnosis relies on immunohistochemical staining to rule out histologically similar cancers with different prognoses and treatment strategies (e.g., lymphoma and hemangiosarcoma). HM are generally treatment refractory with overall survival of less than 6 months. A lack of understanding regarding the mechanisms of disease development and progression hinders development of novel therapeutics. While the study of human tumors can benefit veterinary medicine, the rarity of the suggested orthologous disease (dendritic cell sarcoma) precludes this. This study aims to improve the understanding of underlying disease mechanisms using genome-wide DNA copy number and gene expression analysis of spontaneous HM across several dog breeds. Extensive DNA copy number disruption was evident, with losses of segments of chromosomes 16 and 31 detected in 93% and 72% of tumors, respectively. Droplet digital PCR (ddPCR) evaluation of these regions in numerous cancer specimens effectively discriminated HM from other common round cell tumors, including lymphoma and hemangiosarcoma, resulting in a novel, rapid diagnostic aid for veterinary medicine. Transcriptional analysis demonstrated disruption of the spindle assembly complex, which is linked to genomic instability and reduced therapeutic impact in humans. A key signature detected was up-regulation of Matrix Metalloproteinase 9 (MMP9), supported by an immunohistochemistry-based assessment of MMP9 protein levels. Since MMP9 has been linked with rapid metastasis and tumor aggression in humans, the data in this study offer a possible mechanism of aggression in HM.

Infantile systemic juvenile xanthogranuloma case with massive liver infiltration

Infantile systemic juvenile xanthogranuloma (ISJXG) is an uncommon form of juvenile xanthogranuloma, a non-Langerhans cell proliferation of infancy and early childhood. In a small percentage of patients, the visceral involvement—most commonly to the central nervous system, liver, spleen, or lungs—may be associated with severe morbidity, and eventually fatal outcome. Here we describe the clinical and pathological findings of a 28-day-old girl with ISJXG who died with respiratory distress syndrome. She had few cutaneous lesions but massive liver and spleen infiltration; other affected organs were multiple lymph nodes, thoracic parasympathetic nodule, pleura, pancreas, and kidneys. Additional findings were mild pulmonary hypoplasia and bacteremia. Immunohistochemistry on fixed tissues is the standard for diagnosis. Immunophenotype cells express CD14, CD68, CD163, Factor XIIIa, Stabilin-1, and fascin; S100 was positive in less than 20% of the cases; CD1a and langerin were negative. No consistent cytogenetic or molecular genetic defect has been identified. This case demonstrates that the autopsy is a handy tool, because hepatic infiltration, which was not considered clinically, determined a restrictive respiratory impairment. In our opinion, this was the direct cause of death.

Primary Tonsillar Epithelioid Follicular Dendritic Cell Sarcoma: Report of a Rare Case Mimicking Undifferentiated Carcinoma and a Brief Review of the Literature

We present a 52 years old male with a left tonsillar follicular dendritic cell sarcoma with prominent epithelioid features that on light microscopical examination bore a striking resemblance to a lymphoepithelial or undifferentiated carcinoma. The tumor was immunohistochemically positive for CD21 and CD35 and negative for cytokeratins. Two distinct histopathological features (both present in our case) that may serve as clues to the correct diagnosis on light microscopical examination were formation of ectatic pseudovascular spaces lined by malignant cells and the presence of non-neoplastic multinucleated giant cells. Familiarity with the above-mentioned morphological clues, and awareness that this tumour may occur in anatomical sites outside the lymph node, are essential for accurate diagnosis.

Indeterminate Dendritic Cell Tumor: A Report of Two New Cases Lacking the ETV3-NCOA2 Translocation and a Literature Review

Indeterminate dendritic cell tumor (IDCT) is a cutaneous proliferation of histiocytes that share morphologic and immunophenotypic properties with Langerhans cells. IDCT was recently included in the updated WHO classification of tumors of hematopoietic and lymphoid tissues. Recent studies have shown that some cases of IDCT demonstrate an ETV3-NCOA2 translocation, supporting the idea that IDCT is a clonal neoplasm. We report 2 new cases of IDCT at our institution lacking the ETV3-NCOA2 translocation. We also present a comprehensive review of reported cases of IDCT in the medical literature. Eighty-five cases of IDCT were reported in the literature between 1985 and 2016. The median age at diagnosis was 45 years. In contrast to Langerhans cell histiocytosis, IDCT is limited to the skin in the majority of cases (88%) and generally follows an indolent clinical course. Most reported lesions are cured with complete excision. However, the histologic features of IDCT and langerhans cell histiocytosis are similar. Conjoint immunostaining for CD1a and langerin is necessary for optimal classification.

Indeterminate Cell Histiocytosis – Case Report and Review of Literature

Introduction. Indeterminate cell histiocytosis is a rare proliferative disorder of indeterminate dendritic cells, reported in only 50 case reports so far. It is clinically presented as yellow, red or brown papules and nodules that appear in otherwise healthy adult individuals. Indeterminate cells are distinct dendritic cells of the skin that have ultrastructural similarities to the epidermal Langerhans cells but do not contain the characteristic Birbeck’s granules and they are also langerin-negative, unlike LCH. Indeterminate cell histiocytosis is an exceptional entity with variable clinical, histopathologic or immunohistochemical findings, sharing morphologic and immunophenotypic features with both Langerhans- and non-Langerhans cell histiocytoses. Case Report. We present a case of indeterminate histiocytosis in a 77-year-old man with 3-year history of asymptomatic, multiple reddish and brown papules and nodules over the entire body, including the oral mucosa. Skin biopsy was done, and histopathological analysis with immunohistochemistry was performed. The positive ICH staining of cells for CD68, CD1a, and S-100 enabled us to diagnose ICH in our patient. Also, BRAF V600E mutation was detected in tumor tissue. The treatment was started with methotrexate that was effective for 6 months, but due to the disease recurrence, further therapy with thalidomide was advised, without effect. Conclusion. Indeterminate histiocytosis is a rare disease, therefore no standardized treatment has been established and the treatment options are limited.

Interdigitating dendritic cell sarcoma located in the groin: a case report and literature review

Interdigitating dendritic cell sarcoma (IDCS) is an extremely rare subtype of dendritic cell neoplasms, and current knowledge on this tumor is limited. We herein report a case of an IDCS in a 64-year-old man who presented with a right inguinal mass combined with extensive retroperitoneal, pulmonary, hepatic, renal, and bone marrow infiltration. Because of the advanced stage of the disease, we performed five cycles of chemotherapy, including cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP); doxorubicin, bleomycin, vinblastine, and dacarbazine (ABVD); and ABVD combined with cisplatin, and one cycle of radiotherapy. The patient’s inguinal mass became smaller during the treatment, but there was no change in the extent of infiltration at the other sites. The patient died 8 months after the initial diagnosis. We also herein review the etiology, diagnosis, differential diagnosis, treatment, and prognosis of IDCS, and analyze the characteristics of IDCS in Chinese patients.

Targeting MEK in a Translational Model of Histiocytic Sarcoma

Histiocytic sarcoma in humans is an aggressive orphan disease with a poor prognosis as treatment options are limited. Dogs are the only species that spontaneously develops histiocytic sarcoma with an appreciable frequency, and may have value as a translational model system. In the current study, high-throughput drug screening utilizing histiocytic sarcoma cells isolated from canine neoplasms identified these cells as particularly sensitive to a MEK inhibitor, trametinib. One of the canine cell lines carries a mutation in PTPN11 (E76K), and another one in KRAS (Q61H), which are associated with the activation of oncogenic MAPK signaling. Both mutations were previously reported in human histiocytic sarcoma. Trametinib inhibited sensitive cell lines by promoting cell apoptosis, indicated by a significant increase in caspase 3/7. Furthermore, in vitro findings were successfully recapitulated in an intrasplenic orthotopic xenograft mouse model, which represents a disseminated aggressive form of histiocytic sarcoma. Mice with histiocytic sarcoma xenograft neoplasms that were treated with trametinib had significantly longer survival times. Target engagement was validated as activity of ERK, downstream of MEK, was significantly downregulated in neoplasms of treated mice. Additionally, trametinib was found in plasma and neoplastic tissues within projected therapeutic levels. These findings demonstrate that in dogs, histiocytic sarcoma may be associated with a dysfunctional MAPK pathway, at least in some cases, and may be effectively targeted through MEK inhibition. Clinical trials to test safety and efficacy of trametinib in dogs with histiocytic sarcoma are warranted, and may provide valuable translational information to similar diseases in humans. Mol Cancer Ther; 17(11); 2439-50. ©2018 AACR.

[Histiocytic and dendritic cell neoplasms: Review of the literature]

Histiocytic and dendritic cell neoplasms (HDN) are rare and their biology, prognosis, treatment and terminology are still under discussion. They are composed of macrophage and dendritic-derived cells and show a wide range of clinical, morphological and prognostic features. Clinicopathological correlation and a broad immunohistochemical panel are required to establish a correct diagnosis. After the detection of BRAF mutations in Langerhans cell histiocytosis, the potential role of other molecular alterations is being studied. We have reviewed the literature published in the last 10 years to provide an overview of NHD, with particular emphasis their molecular features.

High frequency of clonal IG and T-cell receptor gene rearrangements in histiocytic and dendritic cell neoplasms

The 2008 World Health Organization (WHO) diagnostic criteria of histiocytic and dendritic cell neoplasms from hematopoietic and lymphoid tissues no longer required the absence of clonal B-cell/T-cell receptor gene rearrangements. It is true that the clonal B-cell/T-cell receptor gene rearrangements have been identified in rare cases of histiocytic and dendritic cell neoplasms, such as those with or following lymphoma/leukemia or in some sporadic histiocytic/dendritic cell sarcomas, but the clonal features of such group of tumor are still not clear. Here we investigated the clonal status of 33 samples including Langerhans cell histiocytosis (LCH), Langerhans cell sarcoma (LCS), follicular dendritic cell sarcoma (FDCS), interdigitating dendritic cell sarcoma (IDCS) and histiocytic sarcoma (HS). Among them, twenty-eight cases were sporadic without current or past lymphoma/leukemia. Three cases were found with a past history of T-cell lymphoma, one case was followed by extraosseous plasmacytoma, and one case was found with diffuse large B-cell lymphoma (DLBCL). Our results showed that there was a high frequency of clonal IG and T-cell receptor gene rearrangements in these cases. Notably, 4 cases of LCH and 2 cases of FDCS showed both B and T cell receptor gene rearrangements concurrently. One case of FDCS synchronous with DLBCL showed identical clonal IGH in both tumor populations and clonal TCRβ in FDCS alone. No matter if the presence of clonal receptor gene rearrangements was associated with the tumor origin or tumorigenesis, it might serve as a novel tumor marker for developing target therapy.

Prognostic factors for histiocytic and dendritic cell neoplasms

Histiocytic and dendritic cell neoplasms are rare and poorly studied. We report the clinical characteristics and prognostic factors in such cases in Japan. We investigated the clinical characteristics and survival in 87 adult patients with histiocytic and dendritic cell neoplasms. Fifty patients had histiocytic sarcoma, 12 had Langerhans cell histiocytosis, 11 had follicular dendritic cell sarcoma, 8 had Langerhans cell sarcoma, 6 had interdigitating cell sarcoma and 1 had indeterminate dendritic cell sarcoma. The median follow-up period was 18.0 (range: 9.6-71.8) months, and median overall survival (OS) was 23.5 months. The 2-year OS rate was 49.2%. In the multivariate analysis, elevated lactate dehydrogenase (LDH) (p =.004), ECOG performance status (PS) 2-4 (p =.006), and Ann Arbor stage III-IV (p =.008) affected OS. Stratification by elevated LDH, ECOG PS 2-4, and Ann Arbor stage III-IV allowed classification of patients into low risk, intermediate risk, and high risk groups. The same classification was applicable for HS and non-HS categories. In the rare neoplasms of histiocytic and dendritic cell sarcoma, ECOG PS, Ann Arbor stage, and LDH are important prognostic factors for predicting survival.

Spindle Cell Melanoma and Interdigitating Dendritic Cell Sarcoma: Do They Represent the Same Process?

Intranodal spindle cell lesions on biopsy are problematic for a surgical pathologist, often requiring an extensive immunohistochemical evaluation with variable and frequently unsatisfactory results. In the absence of a history of malignancy, the differential diagnosis of a spindle cell tumor must include both a primary nodal proliferation and a metastatic process. Particularly challenging are those lesions that share morphologic and immunohistochemical features; spindle cell melanomas (SCM) and interdigitating dendritic cell sarcomas (IDCS) belong to this category. At present, electron microscopy is the only method proposed to distinguish between the 2 entities; however, this method is often unavailable and impractical. In this study, we assessed the comparative immunophenotypes of 18 cases of SCM and 8 cases of IDCS, with particular emphasis on the expression of MUM-1, β-catenin, SOX-10, MiTF, and p75. Our results showed nearly equivalent staining patterns and profiles; 12% and 17% of IDCS and SCM were labeled for MUM-1, 75% and 83% stained for β-catenin, 0% and 24% expressed MiTF, and 100% and 94% labeled for p75, respectively. All cases of IDCS and SCM displayed strong nuclear reactivity for SOX-10. On the basis of our study and pertinent literature, the morphologic and immmunophenotypic features of SCM and IDCS appear to be virtually indistinguishable from one another, raising the question as to whether these 2 entities represent a pathobiologically similar or even identical process.

Histiocytic and dendritic cell neoplasms: what have we learnt by studying 67 cases

Tumors derived from histiocytic and dendritic cells encompass a large and heterogeneous group of neoplastic and reactive conditions, and their diagnosis is challenging both for pathologists and clinicians. Diagnosis is based on morphological and phenotypical findings, but hybrid features are not uncommon. Furthermore, recent studies uncovered the molecular mechanisms driving some of these tumors, improving diagnostic adequacy, and providing the basis for effective therapeutic breakthroughs.Sixty-seven cases were submitted to the accessory cell and histiocytic neoplasms session at the European Association of Haematopathology/Society for Hematopathology workshop 2016 held in Basel, Switzerland. The cases included histiocytic sarcomas (HS), Langerhans cell tumors (LCT), Erdheim-Chester disease, interdigitating dendritic cell sarcomas (IDCS), indeterminate dendritic cell tumors (IND-DCT), follicular dendritic cell sarcomas, and blastic plasmacytoid dendritic cell neoplasms. Rosai-Dorfman disease and, more rare, conditions such as ALK-positive histiocytosis were also submitted. These cases illustrated classical and unexpected features at morphological, phenotypical, and molecular levels, providing a valuable compendium for pathologists confronting with these tumors.The paper summarizes the most notable features of every single group of diseases, with comments about the most challenging issues, in the attempt to provide practical indications for their recognition.

Characteristics, management, and outcomes of patients with follicular dendritic cell sarcoma

Dendritic cell sarcomas are rare tumours of antigen presenting cells. Data regarding their biology, management and outcomes are sparse. We analysed 66 patients with follicular dendritic cell sarcoma (FDCS). Six patients also had Castleman disease, 9 had another malignancy and 13 had an autoimmune disease. Fifty-four per cent of patients presented with localized disease and 46% with systemic involvement. The median progression-free (PFS) and overall survival (OS) following frontline therapy was 21 and 50 months, respectively. Survival outcomes were significantly inferior in patients with extranodal, bulky or intra-abdominal disease at presentation. Stage was not associated with survival. Management approaches were heterogeneous. Patients who underwent an upfront gross total resection (GTR) experienced better PFS and OS (both P < 0·0001). In patients who underwent a GTR, consolidative radiotherapy was associated with improved local control (P = 0·03), PFS (P = 0·04) and OS (P = 0·05). In patients with measureable disease, gemcitabine with a taxane yielded an overall response rate of 80%. The pattern of relapse was predominantly locoregional. Salvage rates after recurrence were poor. Studies are underway at our institution to define the genomic profile in FDCS and identify potential novel therapeutic targets.

Histiocytic sarcoma with bladder involvement: Case report and literature review

We report an unusual case of histiocytic sarcoma with bladder involvement. An 80 year-old man with a previous history of diffuse large B-cell malignant lymphoma presented with hematuria and back pain. Serial urine cytologies revealed no urothelial malignant cells, but cystoscopy showed a large intravesical mass. The patient underwent transurethral resection (TUR) of the tumor. The bladder TUR specimen showed a widely infiltrating epithelioid neoplasm, with intense immunohistochemical positivity for CD45 and histiocytic markers (CD68, lysozime and fascin). Histopathological diagnosis was histiocytic sarcoma. As the patient's condition was progressively deteriorating, only palliative care was indicated and he died one month after TUR. Although histiocytic sarcoma can often be widespread at the time of diagnosis, to our knowledge, this is the first report of a case presenting with urinary symptoms. Histiocytic sarcoma can mimic many other malignant lesions, and only immunohistochemistry can define the tumor cells, allowing correct therapy. We discuss the differential diagnosis and possible associations.

Angioimmunoblastic T-Cell Lymphoma: A Questionable Association with Follicular Dendritic Cell Sarcoma

An elderly woman presented with generalized lymphadenopathy, several systemic symptoms, and splenomegaly. An inguinal lymph node excision revealed a compound picture. One aspect of the lymph node morphology, including cells with follicular T-helper cell phenotype, was most consistent with angioimmunoblastic T-cell lymphoma. The other component, revealing spindle cells forming whorls with immunostaining for CD21, CD23, and fascin, might be an integral part of this T-cell lymphoma. However, due to the often massive involvement of the nodal tissue by these follicular dendritic cells, these areas were questionably suggestive of involvement by follicular dendritic cell sarcoma. We raise herein the issue of the borderline area between advanced follicular dendritic cell expansion in angioimmunoblastic T-cell lymphoma and a massive follicular dendritic cell proliferation consistent with follicular dendritic cells sarcoma, in the absence of a genomic analysis.

Reduced angiogenic gene expression in morbillivirus-triggered oncolysis in a translational model for histiocytic sarcoma

Histiocytic sarcoma represents a rare malignant tumour with a short survival time, indicating the need of novel treatment strategies including oncolytic virotherapy. The underlying molecular mechanisms of viral oncolysis are largely unknown. As cancer in companion animals shares striking similarities with human counterparts, we chose a permanent canine histiocytic sarcoma cell line (DH82 cells) to identify global transcriptome changes following infection with canine distemper virus (CDV), a paramyxovirus closely related to human measles virus. Microarray analysis identified 3054 differentially expressed probe sets (DEPs), encoding for 892 up‐ and 869 down‐regulated unique canine genes, respectively, in DH82 cells persistently infected with the vaccine strain Onderstepoort of CDV (DH82‐Ond‐pi), compared to non‐infected DH82 cells. Up‐regulated genes were predominantly related to immune processes, as demonstrated by functional enrichment analysis. Moreover, there was substantial enrichment of genes characteristic for classically activated M1 and alternatively activated M2 macrophages in DH82‐Ond‐pi; however, significant polarization into either of both categories was lacking. ‘Angiogenesis’ was the dominant enriched functional term for the down‐regulated genes, highlighting decreased blood vessel generation as a potential mechanism of paramyxovirus‐induced oncolysis in DH82 cells. The anti‐angiogenic effect of infection was verified by immunohistochemistry, which revealed a lower blood vessel density in an in vivo mouse model, xenotransplanted with DH82‐Ond‐pi, compared to mice transplanted with non‐infected DH82 cells. Reduction in angiogenesis appears to be an important oncolytic mechanism of CDV in DH82 cells, suggesting that similar mechanisms might account for human histiocytic sarcoma and maybe other tumours in conjunction with measles virus.

Primary Orbital Histiocytic Sarcoma in a Child Successfully Treated With Multiagent Chemotherapy

Histiocytic sarcoma (HS), a malignant proliferation of mature tissue histiocytes presenting with single or multifocal extranodal tumors, is rarely seen in children. Primary orbital HS has never been reported in a child. Disseminated disease to the bone marrow typically has an aggressive course and poor prognosis. There is no consensus currently on the optimal therapeutic approach for HS. We present the case of a 2-year-old girl with orbital HS with likely bone marrow involvement treated successfully with multiagent chemotherapy, now in complete remission and disease free 3.5 years from end of therapy.

Follicular dendritic cell sarcoma treated with a variety of chemotherapy

Follicular dendritic cell sarcoma (FDCS) is a very rare malignant tumor derived from follicular dendritic cells. Radical resection is the standard therapy for patients with local disease, but an optimal chemotherapy regimen has not been determined for unresectable disease. We report our experience of an FDCS patient with multiorgan involvement. In the present case, disease was only located in the pancreas initially and radical resection was performed. Multiple metastasis developed after the treatment and several factors that indicated a poor prognosis were observed. The present case had a very poor prognostic disease but survived for a long time with a good performance status because of the multiple chemotherapy regimens, which follow therapeutic strategies for malignant lymphoma and soft tissue sarcoma. As far as we know, this is the first study reporting the indication of bendamustine for FDCS patients.

The 2016 revision of the World Health Organization classification of lymphoid neoplasms

A revision of the nearly 8-year-old World Health Organization classification of the lymphoid neoplasms and the accompanying monograph is being published. It reflects a consensus among hematopathologists, geneticists, and clinicians regarding both updates to current entities as well as the addition of a limited number of new provisional entities. The revision clarifies the diagnosis and management of lesions at the very early stages of lymphomagenesis, refines the diagnostic criteria for some entities, details the expanding genetic/molecular landscape of numerous lymphoid neoplasms and their clinical correlates, and refers to investigations leading to more targeted therapeutic strategies. The major changes are reviewed with an emphasis on the most important advances in our understanding that impact our diagnostic approach, clinical expectations, and therapeutic strategies for the lymphoid neoplasms.

Canine Histiocytic Malignancies-Challenges and Opportunities

Canine histiocytic malignancies (HM) are aggressive tumors that occur with particularly high frequency in certain breeds including Bernese mountain dogs and flat-coated retrievers. Robust diagnosis of HM commonly utilizes immunohistochemical stains that are broadly ineffective on formalin-fixed tissues; thus the diagnosis is often one of exclusion. Clinical outcomes are generally poor, with frequent metastasis and therapeutic failure lowering overall survival at time of diagnosis to an average of less than two months in the majority of published work. The limited understanding of the molecular mechanisms underlying HM has hindered the development of more effective diagnostic modalities and the identification of therapeutic targets. A potential avenue exists for advancing clinical management of canine cancers through extrapolation from a close counterpart in human medicine. Historically, HM have been compared to the rare and understudied subset of human cancers involving the dendritic lineage, such as dendritic cell sarcoma or Langerhans cell sarcoma. Recent data have now thrown into question the cellular origin of HM, suggesting that the disease may originate from the macrophage lineage. This review summarizes existing knowledge of HM from the clinical, histologic and molecular perspectives, and highlights avenues for future research that may aid the development of novel diagnostic and therapeutic approaches. In turn, a more advanced appreciation of the mechanisms underlying HM should clarify their cellular origin and identify appropriate opportunities for synergistic extrapolation between related canine and human cancers.

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.