Reticulum cell neoplasms of lymph nodes: a clinicopathologic study of 11 cases with recognition of a new subtype derived from fibroblastic reticular cells

Pathologic characteristics of histiocytic and dendritic cell neoplasms

Histiocytic and dendritic cell neoplasms comprise diverse tumors originating from the mononuclear phagocytic system, which includes monocytes, macrophages, and dendritic cells. The 5th edition of the World Health Organization (WHO) classification updating the categorization of these tumors, reflecting a deeper understanding of their pathogenesis.In this updated classification system, tumors are categorized as Langerhans cell and other dendritic cell neoplasms, histiocyte/macrophage neoplasms, and plasmacytoid dendritic cell neoplasms. Follicular dendritic cell neoplasms are classified as mesenchymal dendritic cell neoplasms within the stroma-derived neoplasms of lymphoid tissues.Each subtype of histiocytic and dendritic cell neoplasms exhibits distinct morphological characteristics. They also show a characteristic immunophenotypic profile marked by various markers such as CD1a, CD207/langerin, S100, CD68, CD163, CD4, CD123, CD21, CD23, CD35, and ALK, and hematolymphoid markers such as CD45 and CD43. In situ hybridization for EBV-encoded small RNA (EBER) identifies a particular subtype. Immunoprofiling plays a critical role in determining the cell of origin and identifying the specific subtype of tumors. There are frequent genomic alterations in these neoplasms, especially in the mitogen-activated protein kinase pathway, including BRAF (notably BRAF V600E), MAP2K1, KRAS, and NRAS mutations, and ALK gene translocation.This review aims to offer a comprehensive and updated overview of histiocytic and dendritic cell neoplasms, focusing on their ontogeny, morphological aspects, immunophenotypic profiles, and molecular genetics. This comprehensive approach is essential for accurately differentiating and classifying neoplasms according to the updated WHO classification.

Fibroblastic reticular cell tumor of eyelid: Rare case report and review of literature

Fibroblastic reticular cell tumours (FRCT) originate from the fibroblastic reticular cells (FBRC) which are histiocytic cells, belonging to the dendritic cell family. These tumours are extremely rare, with only a few cases reported in literature. Histomorphologically, they resemble follicular dendritic cell sarcoma (FDCS); however, they differ immunophenotypically. Extranodal presentations are rare. We report a case of malignant FBRC tumour of the left eyelid, in a 23-year-old woman, who had presented with a recurrent swelling over left lower eyelid. Microscopy revealed an ill circumbscribed tumour composed of oval to spindle cells in storiform pattern, sprinkled with lymphocytes. Immunohistochemistry was performed and diagnosis of FRCT was offered. To the best of our knowledge, this is the first report of malignant FBRC tumour arising in the eyelid region. Here we present this extremely rare case with review of the available literature.

Fibroblastic reticular cell tumour of the internal iliac lymph node presenting as a hypervascular lesion and mimicking a pseudoaneurysm: an extremely rare diagnosis

A woman in her 50s presented with a rounded and hypervascular lesion in the right internal iliac lymph node chain, contacting with small branches of the anterior division of the internal iliac artery. Since the lesion matched the blood arterial pool in CT and the patient exhibited multiple vascular abnormalities that suggested segmental arterial mediolysis, a pseudoaneurysm hypothesis was initially made. Arteriography was realised due to the intention for embolisation of the pseudoaneurysm, but the dynamic behaviour during the exam suggested a hypervascular tumour more. An MRI was conducted, bringing new evidence, favouring the possibility of a neoplasm. The lesion excision was performed and sent to pathology. Morphological and immunohistochemical findings suggested a rare case of a fibroblastic reticular cell tumour of the internal iliac lymph node.

Spinal Cord Compression Caused by Fibroblastic Reticular Cell Tumor (FRCT) Originating from Thoracic Spine

BACKGROUND

The authors present the first reported case of a fibroblastic reticular cell tumor (FRCT) presenting with spinal cord compression. FRCTs are the rarest subset of dendritic cell tumors, a specific group of hematologic malignancies. FRCTs reportedly behave similar to low-grade sarcomas as opposed to malignant tumors.

CASE DESCRIPTION

A 45-year-old female patient presented with a 2-and-a-half week history of a flu-like illness and 1 week history of lower limb imbalance. Magnetic resonance imaging revealed an extradural lesion at T3/4 compressing the spinal cord. Initially, the patient was presumed to have metastatic spinal cord compression, and she underwent a decompressive thoracic laminectomy with debulking of the lesion with follow-up adjuvant radiotherapy. However, histology identified a unique primary FRCT originating from spine, not secondary metastatic spinal cord compression. There were no histologically aggressive features likely contributing to the favorable outcome following surgery and adjuvant radiotherapy. Her postoperative recovery was unremarkable, and she recovered fully.

CONCLUSIONS

Although rare, we report the first case of FRCT originating in the spine causing spinal cord compression. The clinical presentation of the case, histologic features of FRCT, and the treatment options are reviewed.

Fine-Needle Cytological Characteristics of Carcinoma Breast with Medullary or Medullary-like Features Masquerading as Dendritic Reticulum Cell Sarcoma: An Attempt to Explore the Reasons for Erroneous Cytologic Interpretation

Background:

Infiltration of tumors by dendritic reticulum cells (DRC) reflects the host immune defense mechanism. We observed three breast carcinomas cases with dense tumor-infiltrating DRC and lymphocytes in fine-needle aspiration (FNA) smears, leading to cytodiagnosis or differential diagnosis of dendritic reticulum cell sarcoma (DRCS). An attempt was made to find out the reason behind such an erroneous interpretation.

Materials and Methods:

Between 2009 and 2014, two cases were diagnosed as DRCS of the female breast by FNA cytology and in one case possibility of DRCS was considered along with medullary breast carcinoma (MBC). We compare and contrast the cytomorphological features of these three cases with those of nine cytologically diagnosed MBC.

Results:

Cases diagnosed as DRCS or MBC showed singly dispersed tumor cells, nuclear pleomorphism, bare nuclei, prominent nucleoli, and presence of lymphocytes. There was no significant difference between the two groups for discohesive clusters, syncytial clusters, plasma cells, neutrophils, foamy histiocytes, and necrosis. However, there was significant difference for presence of cohesive clusters (0% DRCS and 100% MBC, P = 0.00485), severe degree (+++) of pleomorphism (100% DRCS vs. 11.1% MBC, P = 0.01818), +++ DRC (P = 0.04697), and DRC with ++ to +++ enlarged nuclei (P = 0.03333), and pleomorphic nuclei (P = 0.00833). Two of the three cytologically diagnosed DRCS cases proved to be MBC or MBC-like and one as invasive ductal carcinoma. Six of nine cytologically diagnosed MBC cases with histology proved to be invasive breast carcinomas.

Conclusion:

Criteria for cytodiagnosis MBC need a fresh look. Cases with numerous dendritic cells possibly represent MBC.

Nonproliferative and Proliferative Lesions of the Rat and Mouse Hematolymphoid System

The INHAND Project (International Harmonization of Nomenclature and Diagnostic Criteria for Lesions in Rats and Mice) is a joint initiative of the Societies of Toxicologic Pathology from Europe (ESTP), Great Britain (BSTP), Japan (JSTP), and North America (STP) to develop an internationally accepted nomenclature for proliferative and nonproliferative changes in rats and mice. The purpose of this publication is to provide a standardized nomenclature for classifying changes observed in the hematolymphoid organs, including the bone marrow, thymus, spleen, lymph nodes, mucosa-associated lymphoid tissues, and other lymphoid tissues (serosa-associated lymphoid clusters and tertiary lymphoid structures) with color photomicrographs illustrating examples of the lesions. Sources of material included histopathology databases from government, academia, and industrial laboratories throughout the world. Content includes spontaneous lesions as well as lesions induced by exposure to test materials. The nomenclature for these organs is divided into 3 terminologies: descriptive, conventional, and enhanced. Three terms are listed for each diagnosis. The rationale for this approach and guidance for its application to toxicologic pathology are described in detail below.

Clinical significance and epidemiological evolution of epitrochlear lymphadenopathy in pre- and post-highly active antiretroviral therapy era: A systematic review of the literature

Epitrochlear lymphadenopathy is believed to be associated with distinct etiologies, however the evidence for the same is lacking. We systematically reviewed the reported causes of an enlarged epitrochlear lymph node and compared them over different time periods. Epitrochlear lymphadenopathy was encountered in a wide range of diseases, and we found no association with any particular disease.

Diagnostic immunohistochemistry through Rosai-coloured glasses

Over the past three decades, Immunohistochemistry has materially changed the practice of diagnostic surgical pathology. Foundational observations in this field were critical to a reasoned assessment of both the risks and opportunities that immunohistochemistry afforded the surgical pathologist, and our current practice draws heavily on those early assessments. As we collectively look to and acknowledge those who recognized the value of this technique and who helped guide its development as a companion to (not a replacement for) histomorphologic evaluation, we are drawn to those whose mastery of detail and ability to draw common patterns from seemingly unrelated phenomena helped define the diagnostic power of immunohistochemistry. The focus of this review is on one individual, Dr. Juan Rosai, whose contributions transcend the simple linkage of molecular observations to morphology, recognizing novel patterns in both form and color (the latter often the lovely shades of diaminobenzidine), seemingly viewing our diagnostic world at times through an entirely different lens. By looking at Dr. Rosai's early work in this field, reviewing a selection of his seminal observations, particularly in the Immunohistochemistry of thyroid and thymic neoplasia, revisiting how his special insight is often guided by the work of the early masters of morphology, and how his mentorship of others has helped shaped academic surgical pathology practice, perhaps we can get a glimpse through that lens.

Fibroblastic reticular cell tumor of the breast: A case report and review of the literature

Fibroblastic reticular cells (FBRCs) are basic mesenchymal cells that belong to the dendritic cell family. Primary extranodal FBRC tumor (FRCT) cases are rare, with only 19 cases reported in the literature thus far. However, none of these cases originated in the breast tissue. To the best of our knowledge, the present study reported the first FRCT case of the breast in a 57-year-old woman. The patient complained of a painless mass that was located in the right breast and was ~3.5×2.5 cm in size. The patient underwent modified radical mastectomy subsequent to the diagnosis of FRCT after analysis of the lumpectomy specimen. Pathological examination revealed that the tumor was mainly composed of oval and spindle cells, and was infiltrated with lymphocytes and plasma cells. The tumor cells were immunoreactive for vimentin and negative for CD21, CD35 and S-100 protein. Six axillary lymph nodes were found to have been involved. Following surgery, the patient received four cycles of mesna, doxorubicin, ifosfamide and dacarbazine regimen chemotherapy (70 mg adriamycin day 1; 2.0 g ifosfamided days 1-3; 0.4 g dacarbazine day 1-3), which cycled every 21 days. The patient was uneventfully followed-up for 20 months following chemotherapy. In conclusion, the present study reported what appeared to be the first case of primary breast FRCT. The diagnosis, treatment and prognosis details presented in this study will help improve the diagnosis of the disease.

Cytokeratin-positive interstitial reticulum cell tumor: recognition of a potential "in situ" pattern

Cytokeratin-positive interstitial reticulum cell (CIRC) tumor is a very rare accessory cell neoplasm of lymphoid organs derived from fibroblastic reticulum cells, which originate from mesenchymal stem cells. We describe the histologic, immunophenotypical, and molecular features of a CIRC tumor in a 67-year-old woman who underwent hysterectomy, bilateral adnexectomy, and pelvic lymphadenectomy for endometrial carcinoma. An enlarged pelvic node contained circumscribed neoplastic infiltrates in perifollicular and interfollicular areas consisting of large cells arranged in a reticular pattern with nuclear atypia, atypical mitoses, and apoptosis, but without glandular architecture or disruption of overall architecture. The atypical infiltrate coexpressed cytokeratin and vimentin, partially CD68, CD163, and lysozyme, but lacked markers of endometrial carcinoma, consistent with a diagnosis of CIRC tumor. Despite the obviously neoplastic cytological features, immunostains revealed the circumscribed and noninvasive pattern of the lesion, possibly representing an early "in situ" stage of CIRC tumor.

Follicular dendritic cell sarcoma of the head and neck: Case report, literature review, and pooled analysis of 97 cases

BACKGROUND

Follicular dendritic cell sarcoma (FDCS) is a rare lymphoid neoplasm presenting in the head and neck. There are no pooled analyses of head and neck FDCS cases in the English language literature.

METHODS

A MEDLINE and PubMed review of cases from 1978 to February 2014 was performed. Demographics, clinicopathologic data, and outcomes were summarized.

RESULTS

We presented 2 patients and analyzed 97 cases. The mean age was 42.7 years (SD = 16.3 years). Outcomes were available for 76 patients. Tumors ≤4 cm had better disease-free survival (63% vs 28% at 5 years; p = .0282). Locoregional recurrence was significantly less likely with surgery and radiation compared to surgery alone (15% vs 45%; p = .019) and in patients receiving a neck dissection (10% vs 43%; p = .046).

CONCLUSION

This pooled analysis provides the largest sample size of FDCS of the head and neck to date and suggests that radiation and neck dissection may be beneficial to locoregional oncologic control. © 2015 Wiley Periodicals, Inc. Head Neck 38: E2241-E2249, 2016.

Dendritic cell and histiocytic neoplasms: biology, diagnosis, and treatment

BACKGROUND

Dendritic and histiocytic cell neoplasms are rare malignancies that make up less than 1% of all neoplasms arising in lymph nodes or soft tissues. These disorders have distinctive disease biology, clinical presentations, pathology, and unique treatment options. Morphology and immunohistochemistry evaluation by a hematopathologist remains key for differentiating between these neoplasms. In this review, we describe tumor biology, clinical features, pathology, and treatment of follicular dendritic cell sarcoma, interdigitating dendritic cell sarcoma, indeterminate dendritic cell sarcoma, histiocytic sarcoma, fibroblastic reticular cell tumors, and disseminated juvenile xanthogranuloma.

METHODS

A literature search for articles published between 1990 and 2013 was undertaken. Articles are reviewed and salient findings are systematically described.

RESULTS

Patients with dendritic cell and histiocytic neoplasms have distinct but variable clinical presentations; however, because many tumors have recently been recognized, their true incidence is uncertain. Although the clinical features can present in many organs, most occur in the lymph nodes or skin. Most cases are unifocal and solitary presentations have good prognoses with surgical resection. The role of adjuvant therapy in these disorders remains unclear. In cases with disseminated disease, prognosis is poor and data on treatment options are limited, although chemotherapy and referral to a tertiary care center should be considered. Excisional biopsy is the preferred method of specimen collection for tissue diagnosis, and immunohistochemistry is the most important diagnostic method for differentiating these disorders from other entities.

CONCLUSIONS

Dendritic cell and histiocytic cell neoplasms are rare hematological disorders with variable clinical presentations and prognoses. Immunohistochemistry remains important for diagnosis. Larger pooled analyses or clinical trials are needed to better understand optimal treatment options in these rare disorders. Whenever possible, patients should be referred to a tertiary care center for disease management.

Diagnosis and management of Castleman disease

BACKGROUND

Castleman disease is an uncommon lymphoproliferative disorder characterized as either unicentric or multicentric. Unicentric Castleman disease (UCD) is localized and carries an excellent prognosis, whereas multicentric Castleman disease (MCD) is a systemic disease occurring most commonly in the setting of HIV infection and is associated with human herpesvirus 8. MCD has been associated with considerable morbidity and mortality, and the therapeutic landscape for its management continues to evolve.

METHODS

The available medical literature on UCD and MCD was reviewed. The clinical presentation and pathological diagnosis of Castleman disease was reviewed, along with associated disorders such as certain malignancies and autoimmune complications.

RESULTS

Surgical resection remains the standard therapy for UCD, while systemic therapies are required for the management of MCD. Rituximab monotherapy is the mainstay of therapy; however, novel therapies targeting interleukin 6 may represent a treatment option in the near future. Antiviral strategies as well as single-agent and combination chemotherapy with glucocorticoids are established systemic therapies. The management of Castleman disease also requires careful attention to potential concomitant infections, malignancies, and associated syndromes.

CONCLUSIONS

UCD and MCD constitute uncommon but well-defined clinicopathologic entities. Although UCD is typically well controlled with local therapy, MCD continues to pose formidable challenges in management. We address historical chemotherapy-based approaches to this disease as well as recently developed targeted therapies, including rituximab and siltuximab, that have improved the outcome for newly diagnosed patients. Ongoing research into the management of MCD is needed.

A Rare Case of Cytokeratin-Positive Interstitial Reticulum Cell Sarcoma and Review of the Entity

The tumors of dendritic/reticulum cells constitutes the rarest tumors affecting the lymphoid tissues. Among them tumors derived from fibroblastic reticular cells (FBRCs) are very rare, and those of cytokeratin (CK)-positive interstitial reticulum cells (CIRCs) origin are even more rare. These tumors can be easily misdiagnosed as tumors of other dendritic cells, myofibroblastic tumors or even metastatic poorly differentiated carcinomas. Less than twenty such cases have been reported in the literature till date. We present such a rare case of CIRC sarcoma in cervical lymph node of a 64-year-old man.

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

Neoplasms of histiocytic and dendritic cells are rare disorders of the lymph node and soft tissues. Because of this rarity, the corresponding biology, prognosis and terminologies are still being better defined and hence historically, these disorders pose clinical and diagnostic challenges. These disorders include Langerhans cell histiocytosis (LCH), histiocytic sarcoma (HS), follicular dendritic cell sarcoma (FDCS), interdigtating cell sarcoma (IDCS), indeterminate cell sarcoma (INDCS), and fibroblastic reticular cell tumors (FRCT). In order to gain a better understanding of the biology, diagnosis, and treatment in these rare disorders we reviewed our cases of these neoplasms over the last twenty five years and the pertinent literature in each of these rare neoplasms. Cases of histiocytic and dendritic cell neoplasms diagnosed between 1989–2014 were identified using our institutional database. Thirty two cases were included in this analysis and were comprised of the following: Langerhans cell histiocytosis (20/32), histiocytic sarcoma (6/32), follicular dendritic cell sarcoma (2/32), interdigitating dendritic cell sarcoma (2/32), indeterminate dendritic cell sarcoma (1/32), and fibroblastic reticular cell tumor (1/32). Median overall survival was not reached in cases with LCH and showed 52 months in cases with HS, 12 months in cases with FDCS, 58 months in cases with IDCS, 13 months in the case of INDCS, and 51 months in the case of FRCT. The majority of patients had surgical resection as initial treatment (n = 18). Five patients had recurrent disease. We conclude that histiocytic and dendritic cell neoplasms are very rare and perplexing disorders that should be diagnosed with a combination of judicious morphology review and a battery of immunohistochemistry to rule out mimics such as carcinoma, lymphoma, neuroendocrine tumors and to better sub-classify these difficult to diagnose lesions. The mainstay of treatment for localized disease remains surgical resection and the role of adjuvant therapy is unclear. In patients with multiple areas of involvement, treatment at tertiary care centers with multimodality treatment is likely needed. Accurate subset diagnosis will contribute to better data as well as treatment outcomes analysis of these rare disorders of adult patients in the future.

Fibroblastic Reticulum Cell Tumor of Spleen: A Case Report

Fibroblastic reticulum cells (FBRCs) belong to a major subtype of stromal support cells in the lymphoid system and rarely give rise to tumors. We report a case of fibroblastic reticulum cell tumor arising in the spleen. The tumor was clinically and radiologically mistaken for a metastatic deposit in the spleen. Microscopically the tumor was composed of spindle cells arranged in fascicles and storiform pattern. The cells had oval to elongated vesicular nuclei and pale eosinophilic cytoplasm with indistinct cell borders. There were admixed inflammatory cells, including large numbers of plasma cells. The tumor cells were positive for smooth muscle actin, desmin, AE1/AE3, and MNF116. They were negative for S100, CD1a, CD21, CD23, CD34, CD31, and CD35 among other markers. The morphological features and immunoprofile of this rare tumor in comparison to the few cases reported in the literature are discussed along with the positive reaction with cytokeratins and their relationship to the smaller subset of FBRCs, the cytokeratin-positive interstitial reticulum cells in the spleen.

Pediatric follicular dendritic cell sarcoma of the head and neck: a case report and review of the literature

OBJECTIVE

Follicular dendritic cell sarcoma is a rare disease with a non-specific and insidious presentation that is further complicated by difficult diagnostic and therapeutic assessment.

METHODS

The database PubMed was searched for reports of follicular dendritic cell sarcoma between 1986 (first case published) and 2012. All of the articles presenting informations regarding one or more cases of follicular dendritic cell sarcoma of the head and neck region, in patients less than 18 years of age, were included. The reference lists for pertinent reports were also scanned to ensure that all relevant literature was included.

RESULTS

We present a case of a 14 year-old girl, with a 2-month history of a right-sided level II neck mass. After a carefull radiologic evaluation the mass was resected combined with a right selective neck dissection. Histology with immunohistochemical staining was positive for follicular dendritic cell sarcoma. No recurrence was seen after 31 months follow-up. The literature search identified six more cases of pediatric follicular dendritic cell sarcoma of the head and neck. This is the first female patient with follicular dendritic cell sarcoma in the pediatric population.

CONCLUSIONS

Current treatment of head and neck follicular dendritic cell sarcoma consists of wide radical resection, with associated radiotherapy or chemotherapy only for cases with aggressive disease such as extracapsular invasion, tumor size ≥6 cm or after failure of the first-line surgical treatment.

Novel navigation surgery using image fusion of PET/CT and sonography for axillary neoplasm: First experience

INTRODUCTION

Ultrasound sonography (US)-guided navigation systems are widely used in various organs, including the breast and liver, to locate precisely lesions that are difficult to palpate or isolate after being identified by other imaging techniques. A recent new method, "volume navigation" (Vnav), delivers real-time image fusion of US with other modalities such as MRI, CT, and PET/CT to facilitate identification and excision of suspected pathology.

PRESENTATION OF CASE

The present report describes a novel navigation technique using Vnav-PET/CT, which delivers image fusion of US with PET/CT. To identify the axillary targets using Vnav-PET/CT, we set at least two landmarks then injected 0.2ml viscous blue dye in and around the capsule, which resulted in precise resection. Case 1: A 53-year-old woman with 2 PET/CT-positive lymph nodes in the right axilla underwent easy identification of the targets using the navigation technique followed by lymph node dissection. Among 32 lymph nodes dissected, only the two lymph nodes stained by blue dye were shown histologically to be malignant. Case 2: A 68-year-old woman had a PET/CT-positive lymph node in the left axilla. Vnav-PET/CT easily identified the target, which was successfully dissected under local anaesthesia.

DISCUSSION

This navigation and marking using Vnav-PET/CT helped us easily approach the target, resulted in less surgical time, and avoided unsatisfactory axillary complications. These advances of the navigation system enable us to perform precise minimally invasive surgery.

CONCLUSION

This is the first report of navigation surgery using Vnav-PET/CT, which may assist minimally invasive procedures, especially in the axilla.

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.

A rare case of interdigitating dendritic cell sarcoma in the nasal cavity

Interdigitating dendritic cell sarcoma (IDCS) is an extremely rare neoplasm that mainly arises from the lymphoid tissues of the immune system. Although this neoplasm typically occurs anywhere along the lymph nodes, it can also be found at extranodal sites, especially in the head and neck. We experienced a rare case of extranodal IDCS in the nasal cavity, a location that has not been previously reported. A 73-year-old woman presented with a polyp-like mass in the nasal cavity and underwent endoscopic sinus surgery. A histologic study confirmed the mass as IDCS by immunohistochemistry with S-100 antibody, and postoperative adjuvant radiotherapy was administered. Although the incidence is extremely rare, this case suggests that extranodal IDCS should be considered in the differential diagnosis of nasal cavity masses.

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.

Histiocytic and Dendritic Cell Neoplasms

This article reviews the features of dendritic cells (DCs) of myeloid-derived, plasmacytoid, and follicle-associated types and tumors of these cells, as well as myeloid sarcoma. The morphologic and immunophenotypic features in this group of neoplasms is featured, including mature neoplasms such as Langerhans cell histiocytosis, its malignant counterpart Langerhans cell sarcoma, and S100-negative histiocytic proliferations. More immature or precursor malignancies in this group include myeloid and monocytic leukemias presenting in extramedullary tissues as well as the newly codified blastic plasmacytoid dendritic cell neoplasm. Although likely not related histogenetically to myeloid-derived DCs, mesenchymal-type lymph node tumors including follicular dendritic cell and fibroblastic reticulum sarcomas are also discussed. All of these neoplasms can exhibit a range of immunophenotypic and morphologic features that underscore the plasticity of the non-neoplastic precursors from which they are derived.

Stromal cell contributions to the homeostasis and functionality of the immune system

A defining characteristic of the immune system is the constant movement of many of its constituent cells through the secondary lymphoid tissues, mainly the spleen and lymph nodes, where crucial interactions that underlie homeostatic regulation, peripheral tolerance and the effective development of adaptive immune responses take place. What has only recently been recognized is the role that non-haematopoietic stromal elements have in many aspects of immune cell migration, activation and survival. In this Review, we summarize our current understanding of lymphoid compartment stromal cells, examine their possible heterogeneity, discuss how these cells contribute to immune homeostasis and the efficient initiation of adaptive immune responses, and highlight how targeting of these elements by some pathogens can influence the host immune response.

Primary Follicular Dendritic Cell Sarcoma of the Thyroid Gland Coexisting With Hashimoto’s Thyroiditis

Follicular dendritic cell (FDC) sarcoma, especially of extranodal origin, is an extremely rare malignancy of FDC origin, with only 1 case previously documented in the thyroid. The authors report the case of a 58-year-old female who presented with a painless mass in her neck. The neoplastic cells expressed monocyte/macrophage-specific marker CD68 (KP-1) and lysozymes and the dendritic cell-associated antigens CD35 and Fascin but was negative for CD1a, CD21, and CD23, most consistent with a diagnosis of FDC sarcoma. BIOMED-2 multiplex polymerase chain reaction analysis showed B-cell clonality in both tumor and its adjacent coexisting Hashimoto’s thyroiditis. To the authors’ knowledge, this is the first report of a rare entity of FDC sarcoma primarily involving the thyroid gland coexisting with Hashimoto’s thyroiditis.

Interdigitating Dendritic Cell Tumor of the Lymph Node in the Right Submaxillary Region: A Case Report and Review of the Literature

Interdigitating dendritic cell tumor/sarcoma is an extremely rare neoplasm that mainly occurs in the lymph node, with only 51 cases reported in the literature to date. The authors report the case of a 41-year-old woman who presented with a 4-month history of a gradually enlarging painless mobile lymphadenopathy in the right submaxillary region. The lymph node mass was completely resected and was treated with 1 cycle of CHOP chemotherapy. After 10 months, she was alive with no evidence of disease. Because interdigitating dendritic cell sarcomas are rare and can show morphologic and immunohistochemical heterogeneity, correct diagnosis requires a high index of suspicion and complete pathological study.

Endothelial and virgultar cell formations in the mammalian lymph node sinus: endothelial differentiation morphotypes characterized by a special kind of junction (complexus adhaerens)

The lymph node sinus are channel structures of unquestionable importance in immunology and pathology, specifically in the filtering of the lymph, the transport and processing of antigens, the adhesion and migration of immune cells, and the spread of metastatic cancer cells. Our knowledge of the cell and molecular biology of the sinus-forming cells is still limited, and the origin and biological nature of these cells have long been a matter of debate. Here, we review the relevant literature and present our own experimental results, in particular concerning molecular markers of intercellular junctions and cell differentiation. We show that both the monolayer cells lining the sinus walls and the intraluminal virgultar cell meshwork are indeed different morphotypes of the same basic endothelial cell character, as demonstrated by the presence of a distinct spectrum of general and lymphatic endothelial markers, and we therefore refer to these cells as sinus endothelial/virgultar cells (SEVCs). These cells are connected by unique adhering junctions, termed complexus adhaerentes, characterized by the transmembrane glycoprotein VE-cadherin, combined with the desmosomal plaque protein desmoplakin, several adherens junction plaque proteins including alpha- and beta-catenin and p120 catenin, and components of the tight junction ensemble, specifically claudin-5 and JAM-A, and the plaque protein ZO-1. We show that complexus adhaerentes are involved in the tight three-dimensional integration of the virgultar network of SEVC processes along extracellular guidance structures composed of paracrystalline collagen bundle "stays". Overall, the SEVC system might be considered as a local and specific modification of the general lymphatic vasculature system. Finally, physiological and pathological alterations of the SEVC system will be presented, and the possible value of the molecular markers described in histological diagnoses of autochthonous lymph node tumors will be discussed.

Primary intratesticular spindle cell tumors: interdigitating dendritic cell tumor and inflammatory myofibroblastic tumor

Spindle cell neoplasms arising in the testis are uncommon; most cases belong to the category of gonadal stromal tumors, and the presence of distinctive clinical and pathological features usually lead to a definitive diagnosis. In some instances, however, the diagnosis of these tumors can be challenging and special techniques are needed. The present study reports 2 unusual cases of primary intratesticular tumors showing a striking morphology, characterized by spindle to stellate cells in a lymphoid background. The diagnosis of interdigitating dendritic cell tumor and inflammatory myofibroblastic tumor was established in the 2 cases, and their probable origin in cells of the accessory immune system is discussed. Although both tumors share similar histological features, their immunohistochemical profiles were decisive for a definitive diagnosis.

Angiomatoid Fibrous Histiocytoma: A Review With Recent Genetic Findings

Angiomatoid fibrous histiocytoma is a neoplasm of intermediate biologic potential most often arising in the extremities of children and young adults. Its rarity may lead to misdiagnosis as either a reactive lesion or a benign or higher-grade tumor. Originally described as a type of malignant fibrous histiocytoma, its differentiation remains enigmatic, with precise histogenesis still only hypothesized. Its morphology is distinct, as a circumscribed lesion with sheets of bland spindle to ovoid cells, peripheral lymphoplasmacytic infiltrate, and blood-filled cystic cavities, and half of the cases show strong desmin expression. Cytogenetically, 2 specific translocations, t(12:16)(q13:p11) and more recently t(12:22)(q13:q12), have been characterized. The literature on angiomatoid fibrous histiocytoma is reviewed, particularly with regard to recent molecular genetic developments and differentiation, and its morphology, immunohistochemistry, and differential diagnosis are summarized.

Best practices in diagnostic immunohistochemistry: pleomorphic cutaneous spindle cell tumors

CONTEXT

Pleomorphic cutaneous spindle cell tumors can be difficult to distinguish solely on histologic grounds. The use of ancillary immunohistochemical studies can greatly assist in this differential diagnosis.

OBJECTIVE

To review histologic and immunohistochemical aspects of cutaneous spindle cell tumors and discuss a basic panel of markers to assist in the differential diagnosis.

DATA SOURCES

English-language literature published between 1981 and 2005.

CONCLUSIONS

A basic immunohistochemistry panel for high-molecular-weight cytokeratin, melanocytic markers (S100 protein, HMB-45, Melan-A), smooth muscle actin, desmin, and endothelial markers (CD31, CD34) is effective in diagnosing most cutaneous spindle cell tumors.

Inflammatory myofibroblastic tumours: where are we now?

Inflammatory pseudotumour is a generic term applied to a variety of neoplastic and non-neoplastic entities that share a common histological appearance, namely a cytologically bland spindle cell proliferation with a prominent, usually chronic inflammatory infiltrate. Over the last two decades, inflammatory myofibroblastic tumour (IMT) has emerged from within the broad category of inflammatory pseudotumour, with distinctive clinical, pathological and molecular features. IMT shows a predilection for the visceral soft tissues of children and adolescents and has a tendency for local recurrence, but only a small risk of distant metastasis. Characteristic histological patterns include the fasciitis-like, compact spindle cell and hypocellular fibrous patterns, which are often seen in combination within the same tumour. Chromosomal translocations leading to activation of the ALK tyrosine kinase can be detected in approximately 50% of IMTs, particularly those arising in young patients. This review will examine the clinical, pathological, and molecular genetic features of IMT and discuss an approach to diagnosis and differential diagnosis.

Intra-abdominal Follicular Dendritic Cell Sarcoma With Marked Pleomorphic Features and Aberrant Expression of Neuroendocrine Markers: Report of a Case With Immunohistochemical Analysis

Follicular dendritic cell sarcoma (FDCS) is a very rare malignant tumor arising most frequently in lymph nodes with only few reports of extranodal locations. We report the case of a 35-year-old man with a large retroperitoneal mass. Histologically the tumor was composed of highly pleomorphic cells exhibiting some uncommon features such as an epithelioid appearance, cystic spaces, and multinucleated cells with morphologic features of emperipolesis. Immunohistochemically the neoplastic cells were immunoreactive for CD21, CD23 and CD35. A previously unreported expression of neuroendocrine markers (Synaptophisyn and Neuron-Specific-Enolase) was present. Ultrastructurally no neuroendocrine secretory granules were detected. FDCS can mimic a wide variety of other malignant tumors, and a correct diagnosis requires exclusion of other neoplasms and immunohistochemical confirmation.

Dendritic cell sarcoma: an analytic overview of the literature and presentation of original five cases

Interdigitating and follicular dendritic cell sarcoma (DCS) are very rare diseases, with approximately 184 cases being reported thus far, and their best treatment modality is still on debate. This is a review of all the cases of dendritic cell sarcoma reported from 1981 until April 2006. This review is enriched with the original contribution of five cases occurred at our Institution from 1994 to 2006. The review of the literature pointed out that radical surgery alone was curative in approximately two thirds of these cases, the relapsing rate in patients who received adjuvant treatments being higher than 30%. We pinpoint new five cases of dendritic cell sarcoma (three FDCS and two IDCS). Both the analytic revision of the literature and our data suggest that localized DCS may be effectively treated by radical surgery and do not support the use of adjuvant treatments after radical excision.

Follicular dendritic cell sarcoma of the spleen

Diagnosis of primary spindle cell tumors of the spleen is challenging because of the limited immunologic and cytogenetic characterization of this rare entity. We report a case of primary follicular dendritic cell (FDC) sarcoma of the spleen in a 44-year-old woman. Indications for FDC included positive staining for CD21, Ki-M4P, CD14, and fascin. Expression of both standard FDC markers CD23 and CD35 was detected immunohistochemically using tyramide signal amplification. Cytogenetic analysis revealed multiple clonal chromosomal aberrations involving unbalanced translocations of chromosomes X, 3, 5, 7, 8, 9, and 10, leading to net gains at 3q, 7p, 8q, and 9q and net losses at Xp, 8p, 9p, and 10p. Loss at Xp has been described previously in another tumor with FDC features, suggesting that this aberration might play a common role in this malignancy.