Synchronous Interdigitating Dendritic Cell Sarcoma and B-Cell Small Lymphocytic Lymphoma in a Lymph Node

Primary cutaneous interdigitating dendritic cell sarcoma (IDCS): Report of a new case and literature review

Interdigitating dendritic cell sarcoma is a very rare entity in the spectrum of histiocytic and dendritic cell neoplasms that mostly occurs in lymph nodes, generally presenting as solitary lymphadenopathy, but may affect every organ. Among extra nodal sites, cutaneous interdigitating dendritic cell sarcoma is exceedingly rare; to date, only 9 cases have been described in English literature. The mean age at diagnosis was 60 years, with a male-female ratio of 1,5 to 1; clinically, two different modalities of skin presentation have been reported: solitary, represented by a single red-brownish nodular lesion, or diffuse, characterized by multiple nodular lesions in one or more body districts. The extreme rarity of this sarcoma and its morphological similarity to other poorly differentiated tumors may lead to a delay in diagnosis; in particular, cutaneous localization may be difficult to differentiate from follicular dendritic cell sarcoma, Langerhans cell sarcoma, poorly differentiated squamous cell carcinoma and more generally sarcomatoid carcinoma, atypical fibroxanthoma, malignant melanoma and several sarcomas. Immunohistochemistry plays an important role in identifying this rare entity and formulating a correct histological diagnosis, fundamental requirement for choosing the best therapeutic approach. We report herein a further case of an 81-year-old Caucasian woman who presented to the Dermatology Department to remove an asymptomatic skin papule in the left temporal region, clinically diagnosed as dermatofibroma. The overall pathological and immunohistochemical features supported the diagnosis of a malignant dendritic cell tumor, consistent of interdigitating dendritic cell sarcoma.

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.

Primary cutaneous interdigitating dendritic cell sarcoma is a morphologic and phenotypic simulator of poorly differentiated metastatic melanoma: A report of 2 cases and review of the literature

Interdigitating dendritic cell sarcoma (IDS) is a rare form of hematologic malignancy associated with an aggressive clinical course. Only 4 prior cases have been described as originating in the skin. We encountered two male patients ages 47 and 61years of age who presented with solitary cutaneous neoplasms diagnosed as IDS. Histologic exam showed a coalescing nested and multinodular proliferation of large pleomorphic epithelioid cells. In one case an initial diagnosis of melanoma was rendered. A recurrence 8months later was then interpreted as a primary cutaneous IDS. This patient died of widespread metastatic disease within 2years from his initial surgery. The other patient has recently undergone wide excision and radiation without any recurrence or metastatic disease during this short follow up time period. Both patients had a tumor exhibiting the same phenotypic profile comprising leukocyte common antigen, SOX10, S100, CD68, and CD163 positivity. In reviewing the 4 other reported cases, there is a similar older male predominance (mean age of 58years) although women affected were significantly younger (mean age of 28years); there was a predilection for the proximal extremities and the face. Patients treated with excision only developed recurrent disease with one patient subsequently dying of metastatic disease. Primary cutaneous IDS is a highly aggressive hematologic malignancy that has many overlapping features with poorly differentiated epithelioid and spindle cell melanoma including SOX10 staining. An aggressive treatment protocol at the beginning could optimize patient survival.

Intracranial Interdigitating Dendritic Cell Sarcoma

BACKGROUND AND IMPORTANCE:

This is the first report of a primarily intracranial interdigitating dendritic cell sarcoma (IDCS).

CLINICAL PRESENTATION:

A 39-year-old patient with right hemiparesis underwent complete resection of a large parafalcine tumor with subsequent complete recovery of neurological symptoms. Histologically, the tumor was diagnosed as IDCS. Extensive staging did not reveal any extracranial manifestation of this disease. After 1.5 years, the patient remains recurrence free and is being observed closely.

CONCLUSION:

IDCS are exceedingly rare tumors and so far have not been found intracranially. On the basis of the limited experience with extracranial occurrence, this tumor is best managed by complete resection and careful oncological observation.

Spontaneous regression of interdigitating dendritic sarcoma in a patient with concurrent small lymphocytic lymphoma

Interdigitating dendritic cell sarcoma (IDCS) is a rare tumour; only seven cases of IDCS associated with chronic lymphocytic leucaemia/small lymphocytic lymphoma (CLL/SLL) have been reported. We present the case of a 60-year-old man who presented with fevers, night sweats and significant unintentional weight loss. Investigations led to a diagnosis of synchronous SLL and IDCS. Subsequent fluorodeoxyglucose (FDG) positron emission tomography CT (PET-CT) imaging revealed an unusual clinical course with spontaneously resolving highly metabolic lesions. After 42 months of follow-up, the patient remains free of clinical symptoms and evidence of IDCS.

The genetics of interdigitating dendritic cell sarcoma share some changes with Langerhans cell histiocytosis in select cases

Histiocytic disorders have been noted to have evidence of transdifferentiation; examples of cases with combinations of different lineages have been shown. In our index case, we identified interdigitating dendritic cell (IDC) differentiation in a case of Langerhans cell histiocytosis (LCH). Little is currently known about the genetics of IDC sarcoma (IDCS) because they are exceedingly rare. Using array comparative genomic hybridization (aCGH), we evaluated 4 cases of IDCS and compared them with our index case, as well as genetic abnormalities previously found in LCH. Four cases of paraffin-embedded samples of IDCS and 1 case of LCH with IDC differentiation were evaluated using aCGH. Array CGH results showed no abnormalities in a case of LCH with interdigitating cell differentiation. In 3 of 4 cases of IDCS, genetic abnormalities were identified; 1 case had no identifiable abnormalities. Interdigitating dendritic cell sarcoma case 1 had gains of 3q and 13q; IDCS case 2 had trisomy 12; IDCS case 3 had deletions of 7p, 12p, 16p, 18q, 19q, and 22q; and IDCS case 4 had no detectable abnormalities. Our index case, LCH with IDC differentiation, showed no abnormalities by aCGH. A number of LCH cases do not have detectable genetic abnormalities. In contrast, 3 of 4 cases of IDCS evaluated had identifiable abnormalities by aCGH. Furthermore, 2 of these shared abnormalities, albeit of large genetic regions, with published abnormalities seen in LCH. No recurrent abnormalities were identified in the IDCS cases. However, the possibility of a relationship between IDCS and LCH cannot be entirely excluded by these results.

Langerhans Cell Sarcoma Arising from Chronic Lymphocytic Lymphoma/Small Lymphocytic Leukemia: Lineage Analysis and BRAF V600E Mutation Study

Background:

the phenomenon that histiocytic/dendritic cell sarcomas may be transformed from lymphoproliferative diseases is dubbed ‘transdifferentiation’. Langerhans cell sarcoma (LCS) transdifferentiated from chronic lymphocytic leukemia/small cell lymphoma (CLL/SLL) is extremely rare. The underlying mechanisms of LCS tumorogenesis and its transdifferentiation from CLL/SLL are largely unknown.

Aims:

the authors strive to further characterize LCS, to understand the potential molecular changes in LCS and the underlying mechanisms of CLL/SLL transformation to LCS.

Materials and Methods:

a progressively enlarging right inguinal lymph node from a 68-year-old female patient with a history of CLL was biopsied and submitted for flow cytometry analysis, routine hematoxylin, and eosin (H and E) stain and immunohistochemical study. Furthermore, clonality study (fluorescent in situ hybridization (FISH) analysis with a CLL panel probes) and BRAF V600E mutation study (pyrosequencing and immunostain) were performed.

Results:

two different neoplasms, LCS and CLL/SLL, were discovered to occur simultaneously in the same lymph node. These two entities were shown to be clonally related. More importantly, for the first time, BRAF V600E mutation was detected in LCS.

Conclusions:

LCS can be transdifferentiated from CLL/SLL and BRAF V600E mutation may provide the foundation for alternative therapy of LCS.

Dendritic cell sarcoma: a pooled analysis including 462 cases with presentation of our case series

Dendritic cell tumors are extremely rare and current knowledge on these tumors is limited. The characteristics of three dendritic cell sarcoma subtypes and their optimal treatment approaches are not fully clarified. We aimed to make a systematic review of the literature and enrich the current data with five new cases. Pooled analysis of 462 reported cases revealed that the tumor had no age, gender or racial predilection. Our analysis suggests that the young age, advanced stage, intraabdominal involvement and unfavorable histological features (i.e. large tumor size, absence of lymphoplasmacytic infiltration, coagulative necrosis, high mitotic count) may predict poor prognosis. Subtypes of this tumor have different clinical behaviors with interdigitating dendritic cell sarcoma being the most aggressive form. In general, surgery is the most effective treatment modality and adjuvant radiotherapy has no significant effect on overall survival of patients. The role of chemotherapy for the management of advanced disease is controversial.

Histiocytic/Dendritic Cell Transformation of B-Cell Neoplasms: Pathologic Evidence of Lineage Conversion in Differentiated Hematolymphoid Malignancies

B-cell lymphomas, such as low-grade follicular lymphoma and chronic lymphocytic leukemia/small lymphocytic lymphoma, can transform to histiocytic/dendritic cell sarcoma (H/DS) in rare cases. The diagnosis of this unconventional neoplastic evolution relies on a combination of immunophenotypic analysis and genotypic studies. A genotype identical to that of the primary B-cell neoplasm in a secondary neoplasm with H/DS immunophenotype supports the lineage conversion to H/DS. Putative mechanisms for this unusual phenomenon include dedifferentiation, common immature progenitor, and transdifferentiation models, the latter of which is suggested by clinical laboratory data at the present time. Elucidation of the molecular mechanisms governing this lineage conversion may facilitate the understanding of carcinogenesis of not only hematopoietic but also nonhematolymphoid neoplasms. The clinical outcome of secondary H/DS is dismal, as observed in sporadic cases, and the optimal treatment remains to be determined.

Interdigitating dendritic cell sarcoma presenting simultaneously with acute myelomonocytic leukemia: report of a rare case and literature review

Interdigitating dendritic cell sarcoma (IDCS) is an extremely rare tumor derived from interdigitating dendritic cells. We report the first case of a 64-year-old Chinese woman who was diagnosed with simultaneous IDCS and acute myelomonocytic leukemia (AML-M4). The patient had undergone chemotherapy for breast cancer 6 years previously. Based on the laboratory results, both the IDCS and the AML-M4 in this patient were determined to be of myelogenous origination. Furthermore, a review of 62 IDCS cases (Medline database, key word: IDCS) reported to date revealed that as many as 17 % of the patients had malignant disease and received radiotherapy and/or chemotherapy prior to developing IDCS, and that this group of patients showed worse prognosis compared with counterparts. The patient in the present report showed poor response to four cycles of sequential chemotherapy, and died 6 months after the initial diagnosis.

Clonally related histiocytic/dendritic cell sarcoma and chronic lymphocytic leukemia/small lymphocytic lymphoma: a study of seven cases

Histiocytic and interdigitating dendritic cell sarcomas are rare tumors originating from bone marrow-derived myeloid stem cells. Recent studies have shown evidence of cross-lineage transdifferentiation of B cells in follicular lymphoma to histiocytic and dendritic cell sarcomas. In this study, we report the morphologic, molecular and cytogenetic analysis of seven cases of chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) associated with histiocytic and dendritic cell sarcomas. All seven patients were elderly males (median age 71 years). The B-cell neoplasms preceded the development of the histiocytic and dendritic cell sarcomas in six of seven patients, and one patient had both tumors diagnosed at the same time. The tumors included four interdigitating dendritic cell sarcomas: one Langerhans cell sarcoma, one histiocytic sarcoma and one immature neoplasm with evidence of histiocytic origin. Laser-capture microdissection and PCR analysis showed identical clonal immunoglobulin gene rearrangements in the two phenotypically distinct components in all cases. There was a preferential usage of IGHV4-39 by the V-D-J gene rearrangement. By fluorescence in situ hybridization (FISH) analysis, two cases showed deletion 17p in both components, whereas four cases had normal cytogenetic findings by FISH in the CLL/SLL cells, but acquired cytogenetic abnormalities in the corresponding histiocytic and dendritic tumors. Chromosome 17p abnormalities were the most common cytogenetic abnormality detected in the sarcomas, seen in five of six cases studied. Compared with the CLL/SLL cells, the histiocytic/dendritic cells were largely negative for PAX5, but showed strong expression of PU.1 and variable and weak expression of CEBPβ. Our study provides evidence for transdifferentiation of CLL/SLL B cells to tumors of dendritic and less often histiocytic lineage, and suggests that secondary genetic events may play a role in this phenomenon.

Dendritic cell tumor in a salivary gland lymph node: a rare differential diagnosis of salivary gland neoplasms

Dendritic cell tumors are extremely rare neoplasms arising from antigen-presenting cells of the immune system. We report a case of a 69-year-old man with an unremarkable medical history who presented with a 2-months history of a gradually enlarging painless, firm, mobile, 2 × 2-cm swelling at the caudal pole of the left parotid gland without systemic symptoms. Histologically, the tumor consisted of a spindle cell proliferation in an intraparotideal lymph node. Based on the histopathologic, immunohistochemical and electron microscopic findings, a dendritic cell tumor, not otherwise specified (NOS) in an intraparotideal lymph node was diagnosed.

The patient underwent complete tumor resection, and is currently free of disease, 2 years after surgery. These extremely rare tumors must be distinguished from other more common tumors in the salivary glands. Awareness that dendritic cell tumors may occur in this localization, careful histologic evaluation and ancillary immunohistochemical and electron microscopical analyses should allow for recognition of this entity.

Interdigitating dendritic cell sarcoma following adult liver transplantation: case report and literature review

Interdigitating dendritic cell sarcoma is an extremely rare neoplasm derived from professional antigen presenting cells. We report an unusual case of such a tumor occurring in a 61-year-old woman who had undergone orthotopic liver transplantation for stage IVA2 primary hepatocellular carcinoma with a raised preoperative α-fetoprotein level, followed by tacrolimus-based immunosuppressive therapy. During her subsequent management, the tacrolimus blood levels ranged from 7.9 ng/mL to 16.1 ng/mL. Physical examination revealed bilateral neck and left axillary lymphadenopathy. No evidence of either chronic hepatitis B virus or Epstein-Barr virus could be detected in serum. An excisional biopsy of a right neck lymph node was performed. Microscopically, the normal architecture was diffusely effaced by a proliferation of spindled to ovoid cells arrayed in a fascicular, ill-defined whorled pattern and small lymphocytes were admixed in varying numbers with the tumor cells. Immunohistochemical studies showed that the tumor cells were positive for S100 protein, vimentin and CD68. Based on these findings, the case was diagnosed as an interdigitating dendritic cell sarcoma. The patient unfortunately had no response to 2 cycles of CHOP chemotherapy (cyclophosphamide, doxorubicin, vincristine, and prednisone), and died of wide spread disease 6 months after the original biopsy. We propose that tacrolimus-based immunosuppression was associated with the development of interdigitating dendritic cell sarcoma after liver transplantation in this case.

Histiocytic sarcoma arising in indolent small B-cell lymphoma: report of two cases with molecular/genetic evidence suggestive of a 'transdifferentiation' during the clonal evolution

The biologic relationship between small B-cell lymphoma and histiocytic sarcoma (HS) when occurring in the same patient remains unclear, though recent data suggest a possible 'transdifferentiation' from follicular lymphoma (FL) to HS. We investigated the clonal relationship in two cases of small B-cell lymphoma with subsequent HS. Case 1: A 62-year-old female with splenic marginal zone lymphoma (SMZL) developed HS in a groin lymph node 1 year after the primary diagnosis. PCR/sequence analysis of the IGH gene showed a monoclonal rearrangement carrying an identical nucleotide sequence of PCR products from the spleen with SMZL and the lymph node with HS. Case 2: A 61-year-old female with a remote history of FL developed supraclavicular lymphadenopathy, which was confirmed to be HS. PCR analysis of the HS detected a monoclonal rearrangement of the IGH gene and FISH analysis revealed IGH/BCL2 fusion, a genetic hallmark for FL. The transformed HSs showed partial retention of their prior B-cell lymphomas' signatures, including expression of OCT2 in both cases and expression of BCL6 and enhanced expression of BCL2 in case 2. Both HSs demonstrated hypermutated IGH variable regions, arguing against a common progenitor mechanism of the transformation process. The data suggest a common clonal origin of B-cell lymphoma and subsequent HS occurring in the same patient, indicating that 'transdifferentiation' occurs in other small B-cell lymphomas, in addition to the previously reported FL or B-cell lymphoma with IGH/BCL2.

Clinicopathologic features of histiocytic lesions following ALL, with a review of the literature

We describe the clinicopathologic features of 15 patients who had histiocytic lesions that followed acute lymphoblastic leukemia (ALL). Twenty-one separate histiocytic lesions were evaluated that covered a wide spectrum, some conforming to the usual categories of juvenile xanthogranulomas (5), Langerhans' cell histiocytosis (1), Langerhans' cell sarcoma (4), Rosai-Dorfman disease (1), and histiocytic sarcoma (4). Most were atypical for the category by histology, phenotype, or abnormally high turnover rate. Seven low-grade lesions defied easy categorization and were characterized only as "atypical histiocytic lesion" following ALL. For those evaluated, the molecular signature of the prior leukemia was present in the histiocytic lesion. In 3 of 15 patients, the leukemia and histiocytic lesion shared immunoglobulin H or monoclonal TCR gene rearrangements and, in 4 of 15 patients, clonal identity was documented by fluorescence in situ hybridization. Four patients died of progressive disease, 3 of whom had histiocytic sarcoma and 1 who had an atypical lesion. One patient died of recurrent ALL. The other 10 patients are alive, 7 after recurrences and treatment with surgery and/or chemotherapy. The post-ALL lesions are more aggressive than their native counterparts, but despite the demonstration of the presence of the leukemia signature in 7 of 15 patients, the prognosis is generally favorable, except for patients with histiocytic sarcoma. It remains unclear whether the histiocytic lesions arise as a line from the original ALL or whether transdifferentiation is involved.

Transformation of chronic lymphocytic leukemia/small lymphocytic lymphoma to interdigitating dendritic cell sarcoma: evidence for transdifferentiation of the lymphoma clone

Interdigitating dendritic cell sarcoma (IDCS) is a rare tumor derived from interdigitating dendritic cells. Three cases of IDCS associated with chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) have been described, but no clonal relationship between the 2 neoplasms was demonstrated. We present a detailed case analysis of a CLL/SLL with metachronous IDCS and demonstrate that these 2 neoplasms are clonally related. The IDCS and CLL cells had trisomy 12 and identical monoclonal immunoglobulin heavy chain gene rearrangements. Analysis of transcription factors with a role in myeloid differentiation demonstrated PU.1 up-regulation and C/EBPalpha down-regulation in IDCS compared with CLL. High-density array comparative genomic hybridization also identified gains in part of chromosome 16q in IDCS. Our study demonstrates for the first time clonal transformation of CLL/SLL into IDCS. This phenomenon may be triggered by alterations in lineage-determining transcription programs, which result in transdifferentiation, coupled with additional oncogenic stimuli caused by chromosomal imbalances.

Histiocytic/dendritic cell sarcoma arising from follicular lymphoma involving the bone: a case report and review of literature

Histiocytic/dendritic cell sarcomas arising from follicular lymphoma are very rare and poorly understood lesions. We describe a case, which is unique in that it presented with a hipbone lesion simultaneously with axillary lymphadenopathy. Biopsy of the axillary lymph node showed a low-grade follicular lymphoma. The hipbone lesion was comprised two cell populations, one representing diffuse large B cell lymphoma and the other a histiocytic/dendritic sarcoma. The cells of all three lesions contained an IGH/BCL2 rearrangement, suggesting that both diffuse large B cell lymphoma and histiocytic/dendritic sarcoma differentiation developed from the same low grade precursor (follicular lymphoma). This case illustrates that sarcomatous transdifferentiation of follicular lymphoma can be an unpredictable local phenomenon and that it can occur extra nodally in the bone marrow. It may also occur concurrently with the progression of follicular lymphoma to a diffuse large B cell lymphoma.

Clonally related follicular lymphomas and histiocytic/dendritic cell sarcomas: evidence for transdifferentiation of the follicular lymphoma clone

Rare cases of histiocytic and dendritic cell (H/DC) neoplasms have been reported in patients with follicular lymphoma (FL), but the biologic relationship between the 2 neoplasms is unknown. We studied 8 patients with both FL and H/DC neoplasms using immunohistochemistry, fluorescence in situ hybridization (FISH) for t(14;18), and polymerase chain reaction (PCR)/sequencing of BCL2 and IGH rearrangements. There were 5 men and 3 women (median age, 59 years). All cases of FL were positive for t(14;18). The H/DC tumors included 7 histiocytic sarcomas, 5 of which showed evidence of dendritic differentiation, and 1 interdigitating cell sarcoma. Five H/DC tumors were metachronous, following FL by 2 months to 12 years; tumors were synchronous in 3. All 8 H/DC tumors showed presence of the t(14;18) either by FISH, or in 2 cases by PCR with the major breakpoint region (MBR) probe. PCR and sequencing identified identical IGH gene rearrangements or BCL2 gene breakpoints in all patients tested. All H/DC tumors lacked PAX5, and up-regulation of CEBPbeta and PU.1 was seen in all cases tested. These results provide evidence for a common clonal origin of FL and H/DC neoplasms when occurring in the same patient, and suggest that lineage plasticity may occur in mature lymphoid neoplasms.