Systemic Juvenile Xanthogranuloma Involving the Bone Marrow, Multiple Bones, and the Skin That Developed During Treatment of Acute Lymphoblastic Leukemia in Remission State

Systemic xanthogranuloma involving bone marrow and skin in a case of B-Lymphoblastic Leukemia

Juvenile xanthogranuloma is a benign self-limiting lesion commonly described in infants and young children. It most commonly involves the skin presenting as single or multiple yellowish-brown papules. Clinical scenario with the classic histomorphology showing histiocytic aggregates in the dermis with xanthomatous cytoplasm, toutan type giant cells, immunohistochemistry with positive CD68, CD163, factor XIIIa and negative CD1a and S-100 help in diagnosis. However, diagnosis becomes challenging with predominant systemic bone marrow involvement in post-B-lymphoblastic leukemia settings.

Musculoskeletal imaging features of non-Langerhans cell histiocytoses

The non-Langerhans cell histiocytoses (N-LCH) represent a group of rare diseases with different clinical presentations and imaging features to classical LCH. While there is a long list of entities, only few present with musculoskeletal soft tissue and osseous manifestations alongside the more commonly reported systemic findings. Erdheim-Chester disease (ECD) is typically seen in adults as bilateral and symmetrical long bone osteosclerosis. Rosai-Dorfman disease (RDD) is more commonly seen in children and young adults with bone involvement usually being a manifestation of extra-nodal disease. Primary osseous RDD is very rare, with both displaying rather non-specific imaging features of an expansile lucent lesion with or without an extra-osseous component. Juvenile xanthogranuloma (JXG) is a benign disorder typically seen in very young children. The most common imaging manifestation is a dermal or sub-dermal soft tissue mass. This article reviews the musculoskeletal imaging appearances of the commoner N-LCH.

Rare tumors in pediatric age group: Single center experience from Saudi Arabia

Rare pediatric tumors are heterogeneous group containing a variety of histopathological diseases, they represent approximately 10% of all childhood cancers. These rare tumors had a diversity of histology and clinical behaviors that pose different challenges to the investigators. Exploring different pediatric rare tumors. The data were reviewed, retrospectively, through the medical records of seven rare pediatric diseases between 2012 and 2019. Giant cell fibroblastoma (GCF) presented as painless swelling in the trunk, positive for CD34 with PTEN gene mutation. Neuroglial heterotopic tissue presented in 7 days old girl with facial asymmetry and bulging in the oral cavity, maximal de-bulking was done, histopathology was positive for GFAP and S100p. Left side neck mass, surgically excised revealed non-metastatic salivary grand mucoepidermoid carcinoma. Follow up without any chemotherapy or radiotherapy for 5 years with complete remission. Mesenchymal chondrosarcoma (MCS) presented in maxillofacial bones by persistent nasal bleeding, HEY1-NCOA2 fusion gene confirmed the diagnosis. Extra-osseous Ewing sarcoma (EES) presented as rubbery painless swelling in the scalp with fusion transcript involving EWSR1-FL11. Juvenile xanthogranuloma (JXG) presented by butter fly like skin patch in the face with foamy histiocytes in upper dermis with few Touton giant cells, extensive systemic involvement of lung and bone marrow. Metastatic ovarian choriocarcinoma with choriocarcinoma syndrome received induction two different lines of chemotherapy and consolidated with autologous stem cell transplant. Seven pediatric rare tumors, with different aspects of challenges in diagnosis and management, despite the absence of formal protocols and rarity of other center experiences.

Multiple Xanthogranulomas in a Teenager

Juvenile xanthogranuloma (JXG) is a non-Langerhans cell histiocytosis that typically presents as a solitary lesion in infancy. Multiple lesions, especially in patients over one year of age, are rarely described in the literature. The authors report a case of a 17-year-old female who presented with multiple asymptomatic nodules and plaques. The diagnosis of xanthogranuloma was confirmed with histopathologic examination of foamy histiocytes and the characteristic Touton giant cells. The expected course of multiple JXG in older patients may differ from those presenting with a solitary lesion earlier in life.

Isolated Bone Marrow Non-Langerhans Cell Histiocytosis Preceding RUNX1-Mutated Acute Myeloid Leukemia: Case Report and Literature Review

OBJECTIVES

The prevalence of concomitant myeloid neoplasms was recently reported to be unexpectedly high among adults without non-Langerhans cell histiocytosis (non-LCH); however, the coexistence of non-LCH with RUNX1 genetic aberration has not been reported previously.

METHODS

Herein, we report a 23-year-old woman with severe pancytopenia diagnosed with non-LCH following presentation with pancytopenia and marrow examination showing histiocytosis positive for CD45, CD68, CD136, and lysozyme but negative for CD1a, langerin, and S100.

RESULTS

Whole-exome sequencing showed RUNX1 mutation and NF1 mutation. In the ensuing 6 months, she developed hepatosplenomegaly, and repeat bone marrow evaluation was diagnostic of acute myeloid leukemia (AML). Repeat mutational analysis showed again presence of RUNX1 mutation. She underwent induction therapy but died of septic shock.

CONCLUSIONS

The demonstration of RUNX1 mutation in both non-LCH and AML bone marrow specimens at differing time points is suggestive of a biologic association of both distinct disease entities.