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.

An unusual case of extra-nodal interdigitating dendritic cell neoplasm: sarcoma or not?

INTRODUCTION: Interdigitating dendritic cell sarcoma (IDCS) represents an extremely rare neoplasm frequently originating from T-cell- associated dendritic antigen-presenting cells normally populating the paracortex of lymph nodes. Diagnosis is challenging due to the rarity of this neoplasm and the overlapping features with the other primary and metastatic spindle cell neoplasm, even more, when localized in an extra-nodal site. PATIENTS AND METHODS: Herein we report a case of 48 Years old woman with a six-month history of centimetric, quiet painful mass of the philtrum without other significant comorbidity. RESULTS: Histological report showed a proliferation of quiet bland spindle to plump cell, scattered multinucleated giant cell in a subtle background of lymphocytes. IHC study displays only positivity for S-100 and fine, granular scattered cytoplasmatic stain for CD68; all dendritic IHC markers were negative. Morphological and immunohistochemical analyses were consistent with extra-nodal Interdigitating Dendritic Cell Neoplasm. CONCLUSION: Interdigitating Dendritic Cell Sarcoma is a rare and challenging entity with a variable prognosis. We present a case of extra-nodal IDCS whit low worrisome histological features, emphasizing the need for further efforts to better definitely this rare neoplasm ad its potential for malignancy.

A rare case of cutaneous interdigitating dendritic cell sarcoma.

Interdigitating dendritic cell sarcomas (IDCSs) are aggressive tumors of dendritic cells, often presenting with lymphadenopathy. Fewer than 10 cases of primary cutaneous IDCS have been reported. Histopathologically, IDCS presents as atypical spindle cells with irregular nuclei, and therefore can be difficult to distinguish from melanoma, follicular dendritic cell sarcoma, and Langerhans cell tumors by H&E examination alone. We report a unique case of a man with cutaneous IDCS that was initially misdiagnosed as melanoma. Having previously undergone an excision of a reported "melanoma" on the neck, he presented with a new growth on the cheek. Histopathologic findings revealed an atypical dermal lymphohistiocytic infiltrate around vessels and cells forming nests along the dermal-epidermal junction. Immunohistochemical stains were strongly positive for S100, fascin, and lysozyme; on the other hand, CD1a, langerin, CD21, CD23, and SOX10 were negative. These immunohistochemical findings were consistent with IDCS, and the patient's prior biopsy specimen was then revisited. Similar staining revealed that lesion also to be a cutaneous IDCS. Follow-up imaging with PET scan was negative for metastases, supporting the diagnosis of primary cutaneous IDCS. Our findings contribute to the limited literature on cutaneous IDCS and highlight a potential pitfall in its diagnosis because of overlapping histopathologic features with melanoma.

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.

A Case of Indeterminate Cutaneous Dendritic Cell Tumors in the Setting of Chronic Myelomonocytic Leukemia.

ABSTRACT: Chronic myelomonocytic leukemia (CMML) is a rare hematopoietic stem cell neoplasm. Indeterminate dendritic cell neoplasm (IDCN) is an extraordinarily rare histiocytosis that may manifest secondarily to CMML. A 75-year-old man with a 2-year history of CMML presented for multiple cutaneous lesions on his head and neck. Biopsy results yielded a dense diffuse infiltrate of large pleomorphic cells, which were positive for CD1a, S100, and CD56 with weak positivity for CD43 and CD68. Given his history of CMML, the patient was diagnosed with IDCN. This may indicate a progression of his CMML or transformation to acute leukemia; therefore, a systemic workup was recommended. IDCN may manifest secondary to a wide number of hematopoietic malignancies, with CMML being a rare occurrence. Recorded responses to phototherapy are reassuring, whereas systemic therapy may be appropriate for widespread cases. Remaining vigilant for cutaneous changes in patients with CMML will help prevent misdiagnosis and encourage prompt initiation of appropriate treatment.

Interdigitating dendritic cell sarcoma: analysis of two original extra-nodal cases and review of literature.

Interdigitating dendritic cell sarcoma (IDCS) is a rare, highly malignant tumor with a poor prognosis, and current knowledge of this tumor is limited. It is reported that lymph nodes are the primary localization sites. However, in recent years, many primary IDCS have also been reported in the extra-nodal sites, which undoubtedly increases the difficulty of diagnosis. There are very few reports that systematically analyze the clinicopathologic features of IDCS. Here we described two cases of extra-nodal IDCS and reviewed the literature of 44 other published cases of extra-nodal IDCS. Thus, the clinical symptoms, pathological diagnosis, and therapeutic effects of 46 cases of extra-nodal IDCS were summarized in detail. Considering the paucity of available data with regard to IDCS, a thorough and detailed summary would help to better diagnose and treat this neoplasm.

Retroperitoneal dendritic cell sarcoma: A case report.

RATIOANLE: Interdigitating dendritic cell sarcoma (IDCS) is a rare sarcoma that originates from interdigitating dendritic cells in lymphoid tissue, the imaging characteristics of which are poorly defined. Pathological examination can identify the tumor, but reports on the imaging characteristics of IDCS are limited. PATIENT CONCERNS: Here, we report a case of IDCS in a 48-year-old female involving the retroperitoneal area. The patient had a lumbar mass on her right lower back for 4 years, and which started increasing in size 1 year before. DIAGNOSES: An irregular soft tissue mass (10.1cm × 8.5 cm in size) in the right lower back of retroperitoneum was detected by CT examination with unclear borders, uneven density, and necrosis. The solid components of the mass were significantly enhanced on postcontrast imaging. The soft tissue was irregular and uneven. Cystic solid masses were observed on MRI examination in the right retroperitoneum, lateral abdominal wall, waist, and back. Necrosis, hemorrhage, and cystic transformation were observed inside the lesion. The cyst wall, separation, and wall nodules were significantly enhanced on the postcontrast image. No distant metastasis was observed. Postoperative pathology confirmed the diagnosis of IDCS. INTERVENTIONS: The patient underwent surgical resection. The resected margin was positive, and the patient received adjuvant radiotherapy 2 months after the surgery. OUTCOMES: Twelve months after radiotherapy, the patient's chest CT showed multiple metastases in both lungs. The patient was started on combination chemotherapy of doxorubicin and ifosfamide, and the follow-up is still ongoing. LESSONS: Imaging provides a unique advantage to determine the extent of the IDCS, the invasion of adjacent tissues, and the presence or absence of distant metastases.

New insights inside the interdigitating dendritic cell sarcoma-pooled analysis and review of literature.

Interdigitating dendritic cell sarcoma is a rare haematological neoplasm with high debatable management protocols. The data extracted from 127 case reports published between 1981 and 2018 were analysed. The median age at diagnosis was 58 years with a male to female ratio of 1.65:1. The median OS and PFS of IDCS were 12 and 6 months, respectively, with a disease-specific mortality rate of 36.4%. Two-thirds of patients had a localised disease, while 30% had a disseminated form with 1-year mortality rates of 21.1% and 78.9%, respectively. Twenty per cent of cases were associated with other malignancies. Histologically, the proliferation of large spindle-shaped cells with fascicular growth was described in 84.3% of cases. Based on Cox-regression model, surgical resection was the only treatment modality linked to survival improvement with no recorded survival benefits of radiotherapy and chemotherapy. The 1-year mortality rates in resected and non-resected disease were 17.8% and 63.2%, respectively (P < 0.0001).

[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.

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.

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.

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 tumor: A rare case report with review of literature.

Interdigitating dendritic cell tumor/sarcoma (IDCT) is a very rare and aggressive neoplasm arising from antigen-presenting cells. It usually involves lymph nodes, but extranodal sites can also be involved. Because of the rarity of the disease, consistent standard treatment guidelines have not been established till date. We report a case of a 35-year-old female who presented with right-sided neck swelling and anterior mediastinal mass. Histopathology revealed large mononucleated cells with background of mixed polymorphous inflammatory cells suspicious of Hodgkin's lymphoma. Hence, to confirm the diagnosis, immunohistochemistry was done. Immunohistochemistry revealed that the tumor was CD30 - negative, CD10 - negative, CD2 - negative, leukocyte common antigen - positive, vimentin - positive, and S-100 - positive, diagnostic of IDCT. Patient was treated with eight cycles of cyclophosphamide, doxorubicin, vincristine, and prednisolone regimen chemotherapy followed by involved field radiotherapy and showed dramatic response with complete resolution of mediastinal mass.

Interdigitating dendritic cell sarcoma: Clinicopathologic study of 8 cases with review of the literature.

To investigate the clinicopathologic features and differential diagnoses of interdigitating dendritic cell sarcoma (IDCS), the clinical, morphological and immunohistochemical features of eight cases of IDCS were collected and analyzed. Three patients were males and five were females, the mean age and the median age were 56.5 years and 57 years respectively. Clinically, the majority of cases involved lymph nodes. Microscopically, neoplastic cells were spindle or ovoid, forming fascicles or whorls. Every case had active mitosis figures. Immunohistochemically, these neoplastic cells were consistently positive for S100, but negative for CD21 and specific B-cell and T-cell associated antigens. Follow-up results were available in 7 cases, of which 5 cases of localized lesions survived, 2 cases died of organ involvement. Interdigitating dendritic cell sarcoma is an extremely rare neoplasm, with inferior prognosis and without standard treatment regimen. IDCS has similar but unique clinicopathologic features and the differential diagnoses include other histiocytic and dendritic cell neoplasms and malignant melanoma.