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.

The Disruption of Retroperitoneal Interdigitating Dendritic Cell Sarcoma With Neurogenic Neoplasm As A Result Of Immunohistochemical Markers And Radiological Features

INTRODUCTION

Retroperitoneal localization is an extremely rare presentation of interdigitating dendritic cell sarcoma (IDCS), the primary neoplasm of the antigen-presenting interdigitating dendritic cells.

CASE PRESENTATION

We report an incidentally found isolated retroperitoneal IDCS in a 59-year-old female patient with no prior symptoms. The patient was initially misdiagnosed since the tissue samples obtained by tru-cut biopsies were diffusely positive for S-100, and the radiological features were similar to neurogenic tumors. However, additional immunohistochemical staining in the excisional biopsy specimen revealed IDCS as the correct diagnosis.

CONCLUSION

The correct diagnosis may not always be achieved with tru-cut biopsy evaluations in the retroperitoneal masses. Immunophenotyping and radiological features can occasionally be perplexing. In these cases, an accurate diagnosis can be achieved by excisional biopsy and additional immunohistochemical staining.

Interdigitating dendritic cell sarcoma of pleura, diagnostic challenges of a rare disease

Interdigitating dendritic cell sarcoma (IDCS) is an extremely rare subtype of dendritic cell tumour. The solitary lymph node disease is most commonly seen, but may occasionally present extranodally in skin, intestines, soft tissue, liver or spleen. Here we present a case of IDCS in pleura in 53-year-old man, who presented with loss of appetite and chest pain. The initial biopsy was inconclusive. The patient was started on anti-tubercular treatment considering the higher prevalence of the disease in this part of the world. However, the symptoms worsened after 2 months and repeat PET-CT scan revealed extensive FDG avid lesions in the multiple sites in the body. Repeat PET guided biopsy confirmed this rare IDCS neoplasm. Diagnostic challenges of this rare tumour are discussed.

Histiocytic and Dendritic Cell Sarcomas of Hematopoietic Origin Share Targetable Genomic Alterations Distinct from Follicular Dendritic Cell Sarcoma

Background

Histiocytic and dendritic cell neoplasms are a diverse group of tumors arising from monocytic or dendritic cell lineage. Whereas the genomic features for Langerhans cell histiocytosis and Erdheim‐Chester disease have been well described, other less common and often aggressive tumors in this broad category remain poorly characterized, and comparison studies across the World Health Organization diagnostic categories are lacking.

Methods

Tumor samples from a total of 102 patient cases within four major subtypes of malignant histiocytic and dendritic cell neoplasms, including 44 follicular dendritic cell sarcomas (FDCSs), 41 histiocytic sarcomas (HSs), 7 interdigitating dendritic cell sarcomas (IDCSs), and 10 Langerhans cell sarcomas (LCSs), underwent hybridization capture with analysis of up to 406 cancer‐related genes.

Results

Among the entire cohort of 102 patients, CDKN2A mutations were most frequent across subtypes and made up 32% of cases, followed by TP53 mutations (22%). Mitogen‐activated protein kinase (MAPK) pathway mutations were present and enriched among the malignant histiocytosis (M) group (HS, IDCS, and LCS) but absent in FDCS (72% vs. 0%; p < .0001). In contrast, NF‐κB pathway mutations were frequent in FDCSs but rare in M group histiocytoses (61% vs. 12%; p < .0001). Tumor mutational burden was significantly higher in M group histiocytoses as compared with FDCSs (median 4.0/Mb vs. 2.4/Mb; p = .012). We also describe a pediatric patient with recurrent secondary histiocytic sarcoma treated with targeted therapy and interrogated by molecular analysis to identify mechanisms of therapeutic resistance.

Conclusion

A total of 42 patient tumors (41%) harbored pathogenic mutations that were potentially targetable by approved and/or investigative therapies. Our findings highlight the potential value of molecular testing to enable precise tumor classification, identify candidate oncogenic drivers, and define personalized therapeutic options for patients with these aggressive tumors.

Implications for Practice

This study presents comprehensive genomic profiling results on 102 patient cases within four major subtypes of malignant histiocytic and dendritic cell neoplasms, including 44 follicular dendritic cell sarcomas (FDCSs), 41 histiocytic sarcomas (HSs), 7 interdigitating dendritic cell sarcomas (IDCSs), and 10 Langerhans cell sarcomas (LCSs). MAPK pathway mutations were present and enriched among the malignant histiocytosis (M) group (HS, IDCS, and LCS) but absent in FDCSs. In contrast, NF‐κB pathway mutations were frequent in FDCSs but rare in M group histiocytosis. A total of 42 patient tumors (41%) harbored pathogenic mutations that were potentially targetable by approved and/or investigative therapies.

Histiocytic and dendritic cell neoplasms are a diverse group of tumors arising from the monocytic or dendritic cell lineage. This article presents the molecular characteristics of the four major subtypes of malignant histiocytic and dendritic cell neoplasms, focusing on genomic alterations that could represent therapeutic targets.

[Clinicopathological characteristics and differential diagnosis of interdigitating dendritic cell sarcoma]

Objective: To analyze the clinicopathological features and differential diagnosis of interdigitating dendritic cell sarcoma (IDCS). Methods: The clinical pathological features of 7 IDCS were analyzed. Among them, the follow-up results of 6 cases were available. Results: Among the 7 IDCS patients, 4 cases were male and 3 were female. The age of the patients ranged from 26 to 69 years.Three cases were originated from lymph nodes and 4 cases were originated from skin, stomach, adrenal gland and mesentery, respectively. Microscopically, the tumor cells presented as fascicular and storiform proliferation and infiltrated by lymphocytes. The tumor cells were short-spindle or ovoid, with indistinct border of cytoplasm. The immunohistochemistry results showed that tumor cells were S-100, Vim, CD68 and CD163 positive, and AE1/AE3, EMA, CD117, CD34, Desmin, SMA, CD1α, CD21, CD23, CD35, HMB45, Melan-A, MelanPan and ALK negative.The BRAF mutation and clonal rearrangement of T and B cells were not detected. Among the follow-up period of 7 IDCS patients, 3 occurred disease progressions. Conclusions: IDCS is extremely rare with unique pathological features, and its lesion is not limited to the lymph node. The IDCS patients with extensive lesions may have worse prognose. The differential diagnosis of IDCS includes other histiocytic and dendritic cell neoplasms, malignant melanoma and soft tissue neoplasms.

Histiocytic and Dendritic Cell Neoplasms

Histiocytic and dendritic cell neoplasms are very rare, belonging to a group that share morphologic, immunophenotypic, and ultrastructural characteristics of mature histiocytic/dendritic neoplasms. Histiocytic and dendritic cell neoplasms may arise de novo or in association with B-cell, T-cell, or myeloid neoplasms. Recent molecular findings, particularly the discoveries of the mutations in the RAS-RAF-MEK-ERK pathway, have greatly advanced the diagnosis and treatment options. Histiocytic and dendritic cell neoplasms may closely resemble each other, non-hematopoietic neoplasms, and even reactive processes. Therefore, it is essential to understand the clinicopathologic characteristics, differential diagnoses, and pitfalls of each entity.

A case of interdigitating dendritic cell sarcoma studied by whole-exome sequencing

Interdigitating dendritic cell sarcoma (IDCS) is an aggressive neoplasm and is an extremely rare disease, with a challenging diagnosis. Etiology of IDCS is also unknown and most studies with only case reports. In our case, immunohistochemistry showed that the tumor cells were positive for S100, CD45, and CD68, but negative for CD1a and CD21. This study aimed to investigate the causative factors of IDCS by sequencing the protein-coding regions of IDCS. We performed whole-exome sequencing with genomic DNA from blood and sarcoma tissue of the IDCS patient using the Illumina Hiseq 2500 platform. After that, we conducted Sanger sequencing for validation of sarcoma-specific variants and gene ontology analysis using DAVID bioinformatics resources. Through comparing sequencing data of sarcoma with normal blood, we obtained 15 nonsynonymous single nucleotide polymorphisms (SNPs) as sarcoma-specific variants. Although the 15 SNPs were not validated by Sanger sequencing due to tumor heterogeneity and low sensitivity of Sanger sequencing, we examined the function of the genes in which each SNP is located. Based on previous studies and gene ontology database, we found that POLQ encoding DNA polymerase theta enzyme and FNIP1 encoding tumor suppressor folliculin-interacting protein might have contributed to the IDCS. Our study provides potential causative genetic factors of IDCS and plays a role in advancing the understanding of IDCS pathogenesis.

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.

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.

Head and Neck Extranodal Interdigitating Dendritic Cell Sarcoma: Case Report and Review of the Literature

Interdigitating dendritic cell sarcoma (IDCS) is an exceedingly rare neoplasm originating from professional antigen presenting cells normally located in the T zone of the lymph node. The purpose of this report was to describe the first case of the IDCS of the submandibular gland and perform a review of the literature of head and neck IDCS. We present a case of an 81-year-old man with a 5 months history of slowly enlarging painless mass in right submandibular region. Fine needle aspiration cytology was suggestive of squamous cell carcinoma. The patient underwent surgical resection of the right submandibular gland and neck dissection. A malignant spindle cell proliferation involving the submandibular gland and colonizing one laterocervical lymph node was found. Morphology and immunophenotype prompted a differential diagnosis of a metastatic spindle cell melanoma versus an IDCS. Transmission electron microscopy was performed and supported a diagnosis of IDCS. The diagnosis of IDCS is a challenging task and may require a large array of techniques.

Evidence of BRAF V600E in indeterminate cell tumor and interdigitating dendritic cell sarcoma

BRAF V600E mutations have been reported in several histiocytic and dendritic cell neoplasms. In this case series, we report BRAF V600E-positive histiocytic and dendritic cell neoplasms in association with lymphomas and lymphoid proliferations. This is a review of cases with immunohistochemistry for BRAF V600E, with additional immunohistochemistry to categorize tumors. We report the first case of BRAF V600E-positive indeterminate cell tumor in association with angioimmunoblastic T-cell lymphoma. We also report a case of BRAF V600E-positive interdigitating dendritic cell sarcoma in a patient with positive B-cell polymerase chain reaction. It is unclear if these neoplasms developed as transdifferentiation of lymphoid neoplasms or if they developed independently. These cases illustrate the expanding spectrum of BRAF V600E-positive histiocytic and dendritic cell tumors and suggest that attention should be paid to lymphomas for possible coincident presentation of these disorders.

A case of interdigitating dendritic cell sarcoma/histiocytic sarcoma--a diagnostic pitfall

Interdigitating dendritic cell sarcoma (IDCS) and histiocytic sarcoma (HS) are two distinct rare hematolymphoid neoplasms, and HS derived from a likely pre-existing IDCS has never been reported in the English literature. Diagnosis of such entities in excised specimens is difficult, but becomes more difficult with the scant amount of materials obtained with fine needle aspiration (FNA) and core needle biopsy. Here we present an interesting and unique case of an IDCS located within a mesenteric mass, which was initially diagnosed as IDCS from the cytology of FNA and core needle biopsy specimens. After brief chemotherapy, the patient again developed abdominal pain, and a HS was diagnosed based on the excised segmental small intestinal specimen. While the exact relationship between the IDCS and HS cannot be ascertained, it is most likely that the HS is derived from the IDCS, although co-existing HS in addition to IDCS from the cytology specimen cannot be completely ruled out.

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.

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.

Interdigitating dendritic cell sarcoma occured alone in axilla

Interdigitating dendritic cell sarcoma (IDCS) is a very rare disease around the world and its prognosis is known to be aggressive. This reports a case diagnosed as IDCS of the axillary region treated in Soonchunhyang University Hospital. A 57-year-old female visited Soonchunhyang University Hospital with a left axillary mass. The mass was hard and fixed. Computed tomography observed a 7 cm lymph node at the left axilla, and core biopsy suspected sarcoma. In another study, there was no specific finding except the axillary lesion. Left axillary lymph node dissection (level I, II) was conducted and the pathologic report finally showed IDCS. The patient was treated with only radiotherapy and followed up without recurrence for 13 months up to now. IDCS is a very rare sarcoma that is hard to diagnose and progresses fast. Thus, treatment is very difficult. Proper treatment can be better established after more experiences.