[Juvenile multiple xanthogranuloma in a patient with Langerhans cell histiocytosis]

Synchronous Pulmonary Langerhans Cell Histiocytosis and Multiple Cutaneous Reticulohistiocytomas With a Common BRAF- V600E/D Mutation Driver

ABSTRACT

Histiocytoses constitute a group of heterogeneous disorders characterized by involvement of variable organs by neoplastic macrophage or dendritic cells. They may affect both adults and children with a predilection to the skin, bone, lungs, lymph nodes, and CNS. The coexistence of different types of histiocytoses in the same patient is an extremely rare phenomenon. We describe a very rare case of co-occurring pulmonary Langerhans cell histiocytosis with multiple cutaneous reticulohistiocytomas with a common BRAF- V600E mutation as the driver genetic event in both the lung and skin lesions. The presence of a common BRAF- V600E mutation provides evidence of their clonal relation and contributes to our understanding in the pathogenesis of multiple, co-occurring histiocytic proliferations.

Langerhans Cell Histiocytosis Evolving into Juvenile Xanthogranuloma: Two Linked Entities

BACKGROUND

Langerhans cell histiocytosis (LCH) represents a myeloid clonal proliferation that involves the skin and other organs. Occasionally, cases of LCH evolve into juvenile xanthogranuloma (JXG).

CASE PRESENTATION

A 7-month-old boy presented with an itchy, flaky rash resembling seborrheic dermatitis affecting the scalp and eyebrows. The lesions started at 2 months old. On physical examination, there were reddish/brown lesions on the trunk, denuded areas on the groin and neck, and a large lesion behind his bottom teeth. In addition, there were thick white plaques in his mouth and thick whitish material in both ears. A skin biopsy showed features of LCH. Radiologic examination demonstrated several osteolytic lesions. Chemotherapy produced marked improvement. A few months later, the patient developed lesions with clinical and histologic features of XG.

CONCLUSION

A possible association between LCH and XG is explained by lineage maturation development. Chemotherapy may play a role in modifying the production of cytokines that enhance the transformation or 'maturation' of Langerhans cells into multinucleated macrophages (Touton cells) characteristic of a more favorable proliferative inflammatory condition.

Multiple Xanthogranulomas in an Adult Patient with Myelodysplastic Syndrome

Adult multiple xanthogranuloma (XG) is a rare late-onset variant of juvenile XG. It is characterized by the appearance of papules or nodules located preferably on the trunk. A case of a 54-year-old man with myelodysplastic syndrome is presented as a history of interest, who consulted due to the appearance of multiple brownish papules distributed mainly in the trunk. So far, there are only 22 cases of this clinical form reported in the literature, 9 of them associated with malignant hematological processes. We highlight the importance of this entity as a possible cutaneous marker of blood dyscrasias.

The triptych of mixed histiocytosis: a systematic review of 105 cases and proposed clinical classification

Histiocytoses are one of the ultimate diagnostic challenges that every physician face at least once in his/her life. Giving their protean manifestation and differentiated therapeutic needs, histiocytosis requires extensive characterization and multidisciplinary management. Mixed histiocytosis is an emerging group of syndromes defined by the overlap of Langerhans cell histiocytosis and another histiocytic disorder of different type. Despite rare, it may account for up to a fifth of systemic histiocytosis patients in some series. In this work, we comprehensively review for the first time the clinical, radiological, histopathological and molecular features of mixed histiocytosis in children and adults. Moreover, we propose a clinical classification in three groups that differentiate patients with systemic involvement and worse overall survival to other groups with more localized manifestations and indolent behavior, wanting to ease their recognition and treatment. Interestingly we also found that mixed histiocytosis harbor BRAFV600E mutations with a higher frequency comparing to all other histiocytoses, and may therefore benefit of specific inhibitory drugs.

Aggressive surgical management of recurrent intracranial juvenile xanthogranuloma: case report and review of the literature

INTRODUCTION

Juvenile xanthogranuloma (JXG) with the central nervous system (CNS) involvement is a rare disease entity that remains poorly understood, especially when the condition develops following treatment for Langerhans cell histiocytosis (LCH).

CASE REPORT

A 21-year-old man who was diagnosed with LCH at age 2, several years following which he developed signs and symptoms of CNS involvement. Magnetic resonance imaging (MRI) of the brain revealed JXG with bilateral choroid plexus involvement. As radiation therapy for the intraventricular masses proved unsuccessful, he underwent two surgical resections. In the following years, he developed another large JXG in the meninges, which was managed conservatively until he required surgery due to symptom progression. Twelve years after the first surgery, the patient is in stable condition with no evidence of recurrence.

CONCLUSION

Due to the rarity of JXG in the CNS, optimal treatment strategies and the precise duration of therapy remain to be determined. Future studies should aim to develop an appropriate treatment algorithm for such rare cases.

Rare childhood hybrid histiocytosis of the central nervous system-diagnosed by stereotactic brain biopsy with marked treatment response to clofarabine

Histiocytosis is a heterogeneous group of disease entities, comprised by two main categories, namely Langerhans and non-Langerhans cell histiocytoses. Central nervous system involvement in histiocytosis is considered very rare and is often secondary to affection of anatomically related bone structures and/or multi-organ disease. We present a never-before described case of rare childhood histiocytosis with hybrid features of Langerhans cell histiocytosis and juvenile xanthogranuloma confined to the central nervous system in a 2- and a half-year-old boy with distinct treatment response to clofarabine. The case also emphasizes the diagnostic significance of stereotactic brain biopsy.

Disseminated juvenile xanthogranuloma occurring after treatment of Langerhans cell histiocytosis: a case report

CASE PRESENTATION

An 11-year-old boy presented with a complaint of a painful temporal mass. Brain magnetic resonance imaging (MRI) showed a 3-cm-sized, homogeneously enhancing mass in the greater wing of the left sphenoid bone, which was diagnosed as Langerhans cell histiocytosis (LCH). Chemotherapy with vincristine and prednisolone was performed for 1 year. After 1 year and 11 months off treatment, he developed symptoms such as polydipsia and polyuria. Brain MRI showed thickening of the pituitary stalk with enhancement, suggestive of LCH involvement, and no recurrence in the sphenoid bone. After 4 years and 4 months off treatment, he developed multiple, subcutaneous, asymptomatic, and yellowish variable-sized papules on his face, posterior neck, and back, which were pathologically diagnosed as juvenile xanthogranuloma (JXG). Brain MRI revealed multifocal enhancing skull lesions in the left parietal, right frontal, and left occipital bones, which were also diagnosed as JXG. After 5 years and 8 months off treatment, the number of variable-sized skin lesions was increased without changes in the lesions in the skull and pituitary stalk.

CONCLUSION

We report a case of disseminated JXG occurring after treatment of LCH. These clinical co-presentations suggested a close relationship between their pathogenesis.

Disseminated juvenile xanthogranuloma associated with follicular lymphoma in an adult: successful treatment with chemotherapy and rituximab. A review of the literature

Juvenile xanthogranuloma is a non-Langerhans cell histiocytosis that typically affects children, but several cases have been reported in adults, some in connection with hematologic malignancies. We present the case of a 61-year-old woman with multiple xanthogranulomas who developed a follicular lymphoma after 4 years of follow-up. After 6 months of treatment with chemotherapy and rituximab, the cutaneous lesions disappeared and the patient achieved remission from lymphoma. We highlight this case because xanthogranuloma is a rare disorder that is difficult to diagnose in adults and also because this is the first report of an association between xanthogranuloma and follicular lymphoma. Excellent response was achieved with chemotherapy and rituximab. Finally, given the possible association between xanthogranulomas and hematologic diseases, these lesions may be a cutaneous manifestation of an occult malignancy.

Langerhans cell histiocytosis preceding the development of juvenile xanthogranuloma: a case and review of recent developments

Langerhans cell histiocytosis (LCH) and juvenile xanthogranuloma (JXG) both belong to the histiocytosis group of disorders, which have varied prognostic and clinical significance. Their normal cellular counterparts share a common CD34-positive hematopoietic stem cell precursor that matures along CD14-negative or -positive pathways. Rare cases of LCH and JXG show overlapping findings, suggesting that this divergent maturation is not irreversible. We report a case of an infant diagnosed with cutaneous LCH shortly after birth. Two years after diagnosis, a recurrent lesion in his external auditory canal contained lipidized cells with CD68 and factor XIIIa expression and lacked Birbeck granules and CD1a, consistent with JXG. Our case and previous reports of this phenomenon raise the question of a histogenic relationship between LCH and JXG, and we speculate that the lesional cells of origin are subjected to therapy-induced modulation that results in a varied differentiation.