Bone marrow findings in autoimmune lymphoproliferative syndrome with germline FAS mutation

Orbital histiocytosis; From A to Z

PURPOSE

Histiocytosis is one of the most challenging diseases in medical practice. Because of the broad spectrum of clinical manifestations, systemic involvements, unknown etiology, and complex management, different types of histiocytosis are still a big question mark for us. Orbital histiocytosis is characterized by the abnormal proliferation of histiocytes in orbital tissues. It could affect the orbit, eyelid, conjunctiva, and uveal tract. Orbital histiocytosis can cause limited eye movement, proptosis, decreased visual acuity, and epiphora. In this study, we review the novel findings regarding the pathophysiology, diagnosis, and treatment of different types of histiocytosis, focusing on their orbital manifestations.

METHOD

This review was performed based on a search of the PubMed, Scopus, and Embase databases or relevant published papers regarding orbital histiocytosis on October 9th, 2023. No time restriction was proposed, and articles were excluded if they were not referenced in English.

RESULTS

391 articles were screened, most of them being case reports. The pathophysiology of histiocytosis is still unclear. However, different mutations are found to be prevalent in most of the patients. The diagnostic path can be different based on various factors such as age, lesion site, type of histiocytosis, and the stage of the disease. Some modalities, such as corticosteroids and surgery, are used widely for treatment. On the other hand, based on some specific etiological factors for each type, alternative treatments have been proposed.

CONCLUSION

Significant progress has been made in the detection of somatic molecular changes. Many case studies describe various disease patterns influencing the biological perspectives on different types of histiocytosis. It is necessary to continue investigating and clustering data from a broad range of patients with histiocytosis in children and adults to define the best ways to diagnose and treat these patients.

Lymphoid aggregates in bone marrow: a diagnostic pitfall

Lymphoid aggregates in bone marrow specimens are a relatively frequent finding that may pose a diagnostic challenge for a pathologist. The distinction between reactive and neoplastic aggregates has significant clinical relevance. Although many testing modalities such as immunohistochemistry, flow cytometry and molecular studies are currently available in clinical laboratories, the appropriate utilisation of these modalities and the awareness of their potential pitfalls are important. When a neoplastic process is ruled out, the significance of benign lymphoid aggregates in bone marrow is often unclear, as they may be associated with a broad spectrum of conditions including infections, autoimmune disorders, medications, or may even be idiopathic.This review focuses on evidence-based criteria that can aid in making the distinction between benign and malignant lymphoid aggregates and discusses the advantages, disadvantages and limits of ancillary tests used for this purpose. Finally, the most common aetiologies of benign lymphoid aggregates and their associations with specific diseases are discussed.

Rosai-Dorfman disease mimicking images of meningiomas: Two case reports and literature review

Background:

Rosai-Dorfman disease (RDD) is a rare non-Langerhans cell histiocytic proliferative disorder classically as a massive cervical lymphadenopathy. However, over the years, extranodal locations were confirmed with the central nervous system involvement in less than 5% of cases, which is marked as a significant differential diagnosis of meningiomas, with which they are widely confused due to the similarity of their radiological images.

Case Description:

We report a 37-year-old man and 45-year-old man who were diagnosed with intracranial RDD but whose radiological images mimic meningiomas, requiring anatomopathological and tumor’s immunohistochemistry for definitive diagnosis. Moreover, a review of 184 publications with 285 cases of intracranial involvement of this disease was also performed, comparing these findings with those brought in the previous studies.

Conclusion:

Intracranial Rosai-Dorfman tumors should always be remembered as differential diagnosis of meningiomas since they are similar radiologically and macroscopically. Once remembered and diagnosed, the lesion must be treated following the same pattern of resection done in meningiomas and, treatment’s differences will not occur in the surgical excision technique, but in complementary chemotherapy implementation, radiotherapy, and even with radiosurgery aid, depending on the case. Thus, it is possible to obtain better results than with just the isolated surgical procedure.

Manifestations of Pediatric Extranodal Rosai Dorfman Disease in the head and neck

OBJECTIVES

To systematically evaluate the clinico-diagnostic profile and management outcomes of otorhinolaryngologic manifestations of Extranodal Rosai-Dorfman Disease (ENRDD) in the pediatric population.

METHODS

The search terms Rosai Dorfman Disease and Sinus Histiocytosis were used to query PubMed, Ovid/Medline, and Scopus databases from inception through September 30, 2018. Studies were systematically reviewed in accordance to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) protocol. All reports of ENRDD involving at least one otorhinolaryngologic subsite in children less than 18 years were eligible for inclusion.

RESULTS

A total of 31 studies met inclusion criteria resulting in identification of 31 ENRDD cases with a mean age of 11.5 years. Of the 31 patients, 23 were male (74.2%) and 7 were female (22.6%). Extranodal lesions were limited to otorhinolaryngologic subsites in 24 patients (77.4%), while 7 patients (22.5%) were found to have extranodal lesions simultaneously involving otorhinolaryngologic and nonotorhinolaryngologic sites. The nasal vault was the most common otorhinolaryngologic site involved (n = 13, 41.9%), followed by the paranasal sinuses (n = 10, 32.3%). The most common non-otorhinolaryngologic site that was concurrently involved was the orbit (n = 4, 57.1%). Concurrent cervical lymphadenopathy was present in 19 patients (61.2%). While not documented for 2 cases, emperipolesis on histopathology was confirmed in 29 patients (93.5%). Single therapy with surgical excision was the most common modality of treatment (n = 15, 53.6%) and yielded highest remission rates (80%). In 11 instances (34.36%), ENRDD was misdiagnosed.

CONCLUSION

Pediatric ENRDD is a rare disease entity that maintains a high misdiagnosis potential. The most common otorhinolaryngologic location for extranodal manifestation is the sinonasal compartment. Surgical excision remains the most common treatment modality yielding lowest persistence and/or recurrence rates.

Autoimmune Lymphoproliferative Syndrome: An Overview

Autoimmune lymphoproliferative syndrome (ALPS) is an inherited nonmalignant lymphoproliferative disorder characterized by heterozygous mutations within the first apoptosis signal receptor (FAS) signaling pathway. Defects in FAS-mediated apoptosis cause an expansion and accumulation of autoreactive CD4- and CD8- (double-negative) T cells, leading to cytopenias, splenomegaly, lymphadenopathy, autoimmune disorders, and a greatly increased lifetime risk of lymphoma. The differential diagnosis of ALPS includes infection, other inherited immunodeficiency disorders, primary and secondary autoimmune syndromes, and lymphoma. The most consistent pathologic feature is a florid paracortical expansion of double-negative T cells in lymph nodes. A presumptive clinical diagnosis can be made from symptoms and a constellation of laboratory test results. However, a definitive diagnosis requires ancillary testing and enables disease subclassification. Recognition of ALPS is critical, as treatment with immunosuppressive therapies can effectively reduce or ameliorate symptoms for most patients.

Rosai-Dorfman Disease: The MD Anderson Cancer Center Experience

BACKGROUND

Rosai-Dorfman disease (RDD) is a rare disorder composed of a proliferation of histiocytes with varied clinical manifestations.

PATIENTS AND METHODS

In this retrospective observational study, we obtained demographic, clinical, and outcome data from the medical records of 10 adult patients with RDD seen in the Department of Lymphoma and Myeloma at MD Anderson Cancer Center between 1995 and 2015.

RESULTS

Patients had a median age of 56 years (range, 20-81 years) with equal gender distribution. Five patients were initially treated with systemic therapy. Five received cladribine as initial therapy or for relapse. Other therapeutic agents included clofarabine, lenalidomide, and steroids. The overall response rate was 80% in patients receiving cladribine, with a median progression-free survival of 29 months. Surgery, radiotherapy, and observation were also treatment options for localized disease. With a median follow-up of 65 months, none of the patients have died.

CONCLUSION

Currently, there is no standard of care for RDD. Treatment should be personalized for each patient depending on the clinical presentation, course of the disease, and prior treatment history. Purine analogues provide excellent responses; however, surgical resection and observation are also suitable for specific cases.

Paradoxical CD4 Lymphopenia in Autoimmune Lymphoproliferative Syndrome (ALPS)

Autoimmune lymphoproliferative syndrome (ALPS) is caused by germline or somatic loss of function FAS mutations resulting in impaired apoptosis and consequent expansion of T-lymphocytes causing organomegaly and autoimmune anemia, neutropenia and thrombocytopenia. Herein, we report on a case of disseminated varicella zoster infection after post-partum vaccination in a patient found to have CD4 lymphopenia and eventually diagnosed with ALPS caused by a novel germline missense mutation in FAS death-domain. A subsequent retrospective analysis of 169 patients of the NIH ALPS-FAS cohort, revealed that CD4-T-cells lymphopenia (< 300 cells/μl) may occur in 5% of ALPS-FAS patients irrespectively of the underlying genetic defect, organomegaly or immunosuppressive treatment. Although immunophenotyping did not show depletion of specific CD4-T-cells subpopulations, CD4-lymphopenic ALPS-FAS subjects had an expansion of a subset of circulating T-follicular-helper (cTfh) cells, associated with autoantibody production (CCR7^lowPD-1^high). Furthermore, autoantibodies binding on CD4-T-cells were detected in 50% of the CD4-lymphopenic ALPS-FAS patients and caused cytotoxicity in a natural killer (NK)-mediated antibody-dependent-cellular cytotoxicity assay. Such autoantibodies can therefore be associated with CD4-T-cell death, impaired activation induced proliferation or impaired trafficking. The expansion of autoreactive T-cells in ALPS-FAS is known to be associated with autoimmune clinical manifestations, however our study reveals that ALPS-FAS can also be associated with a paradoxical depletion of CD4-T-cells due to the presence of autoantibodies on the surface of CD4-T-cells which can in turn result in increased susceptibility to opportunistic infections. These novel findings have implications for the diagnosis, clinical monitoring, and management of patients with ALPS-FAS.

Case report of a molar-root incisor malformation in a patient with an autoimmune lymphoproliferative syndrome

Background

Molar-root incisor malformation (MRIM) is a novel dental phenotype likely related to a patient’s past medical history. This case aimed to confirm MRIM by histological and scanning electron microscopy (SEM) examination for the first time in a patient diagnosed with autoimmune lymphoproliferative syndrome (ALPS) and to propose a possible link between ALPS and MRIM that could be attributable to abnormally proliferated bone marrow.

Case presentation

A 12.5-year-old boy with an extensive medical history, including diagnosis of ALPS, was examined clinically and radiologically to elucidate the reason for pain primarily originating from the area of the lower left permanent first molar tooth (PFM; tooth 36). Dental examination and radiographic survey revealed abnormal pulp cavity morphology of all four PFMs, and these were extracted, resolving the dental pain in the patient. The extracted PFMs were subjected to light microscopy, SEM evaluation and mineral density and elemental composition analyses. Histology of two PFMs revealed the presence of dentin-, bone- and cartilage-like tissues with abundant blood vessels occupying the majority of the pulp chamber. The root canals were obliterated with mineralized structures resembling pulp stones. Two different, highly mineralized abnormal tissues filling the majority of the pulp chamber revealed by SEM and confirming the diagnosis of MRIM displayed a mineral density and elemental composition similar to those of enamel and dentin, respectively.

Conclusions

It appears likely that in addition to the complex medical history during early childhood in the present case, extensive lymphoid infiltrates that are possible in ALPS patients can be regarded as a cofactor in the development of MRIM by exerting considerable pressure on the developing tooth bud and providing cells capable of differentiating into diverse cell types.

Immunodeficiency-associated lymphoproliferative disorders: time for reappraisal?

Immunodeficiency-associated lymphoproliferative disorders (IA-LPDs) are pathologically and clinically heterogeneous. In many instances, similar features are shared by a spectrum of IA-LPDs in clinically diverse settings. However, the World Health Organization (WHO) classifies IA-LPDs by their immunodeficiency setting largely according to the paradigm of posttransplant lymphoproliferative disorders but with inconsistent terminology and disease definitions. The field currently lacks standardization and would greatly benefit from thinking across immunodeficiency categories by adopting a common working vocabulary to better understand these disorders and guide clinical management. We propose a 3-part unifying nomenclature that includes the name of the lesion, associated virus, and the specific immunodeficiency setting for all IA-LPDs. B-cell lymphoproliferative disorders (LPDs) are usually Epstein-Barr virus (EBV)⁺ and show a spectrum of lesions, including hyperplasias, polymorphic LPDs, aggressive lymphomas, and, rarely, indolent lymphomas. Human herpes virus 8-associated LPDs also include polyclonal and monoclonal proliferations. EBV^- B-cell LPDs and T- and NK-cell LPDs are rare and less well characterized. Recognition of any immunodeficiency is important because it impacts the choice of treatment options. There is an urgent need for reappraisal of IA-LPDs because a common framework will facilitate meaningful biological insights and pave the way for future work in the field.

Consensus recommendations for the diagnosis and clinical management of Rosai-Dorfman-Destombes disease

Rosai-Dorfman-Destombes disease (RDD) is a rare non-Langerhans cell histiocytosis characterized by accumulation of activated histiocytes within affected tissues. RDD, which now belongs to the R group of the 2016 revised histiocytosis classification, is a widely heterogeneous entity with a range of clinical phenotypes occurring in isolation or in association with autoimmune or malignant diseases. Recent studies have found NRAS, KRAS, MAP2K1, and ARAF mutations in lesional tissues, raising the possibility of a clonal origin in some forms of RDD. More than 1000 reports have been published in the English literature; however, there is a lack of consensus regarding approach for the clinical management of RDD. Although in most cases RDD can be observed or treated with local therapies, some patients with refractory or multifocal disease experience morbidity and mortality. Here we provide the first consensus multidisciplinary recommendations for the diagnosis and management of RDD. These recommendations were discussed at the 32nd Histiocyte Society Meeting by an international group of academic clinicians and pathologists with expertise in RDD. We include guidelines for clinical, laboratory, pathologic, and radiographic evaluation of patients with RDD together with treatment recommendations based on clinical experience and review of the literature.