Cervical Myelopathy due to Odontoid Fracture Induced by Spinal Involvement of Xanthoma Disseminatum: A Case Report.

CASE: A 47-year-old Japanese woman with a medical history of xanthoma disseminatum (XD) presented with posterior neck pain and abnormal gait without a history of trauma. Imaging studies revealed odontoid process thinning resulting in its fracture due to XD involvement in the atlantoaxial joint and subsequent cervical myelopathy. Posterior C1-C2 fusion surgery improved the patient's symptoms. An XD lesion around the odontoid process was confirmed intraoperatively. CONCLUSION: We report cervical myelopathy caused by XD involvement in the C1-C2 joint, showing that early fusion surgery is critical for treating pathological fractures in patients with XD.

A Rare Case of Pediatric Xanthoma Disseminatum With Diabetes Insipidus and BRAF p.V600E Mutation.

ABSTRACT: Xanthoma disseminatum (XD) is a rare non-Langerhans cell histiocytosis characterized by xanthomatous lesions in the absence of hyperlipidemia. XD usually develops in young adults, and there are rare cases among children. BRAF mutations are frequent in Langerhans cell histiocytosis and Erdheim-Chester disease but absent or only rarely detected in other histiocytosis. Herein, we described a 6-year-old Chinese girl presented with generalized skin lesions and diabetes insipidus for 5 months. There were multiple periorbital xanthelasma with histopathological features of foamy histiocytes infiltration with Touton cells. Pituitary magnetic resonance imaging showed pituitary enlargement and pituitary stalk thickening. The presence of BRAF p.V600E mutation makes this case distinctive and also offers a potential therapeutic target. According to our review of the literature, this is the first pediatric XD with diabetes insipidus and BRAF mutation.

Paraneoplastic Multicentric Reticulohistiocytosis on 18F-FDG PET/CT Breast Carcinoma Follow-up.

ABSTRACT: We report the case of a 60-year-old woman who underwent 18F-FDG PET/CT to evaluate a metastatic breast carcinoma. Follow-up 18F-FDG PET/CT showed progressive disease with 18F-FDG increased in primary tumor, axillary lymph nodes, and pleural and bone diffuse metastases but also a concomitant uptake in multiples joints. The anatomopathological analysis from skin biopsy revealed a multicentric reticulohistiocytosis, considered paraneoplastic in the context. Second follow-up PET/CT after treatment showed a decrease of 18F-FDG uptake in previously affected joints, consistent with the symptoms evolution. 18F-FDG PET/CT could be helpful in the detection and the evaluation of such rare systemic disorder.

Xanthoma disseminatum with neurological involvement and optic atrophy: improvement with cladribine.

A 9-year-old boy presented with multiple hyperpigmented papules over flexors with polyuria, polydipsia and progressive loss of vision. Histopathology of papule suggested a diagnosis of non-Langerhans cell histiocytosis and systemic evaluation showed central diabetes insipidus and optic atrophy. With a diagnosis of xanthoma disseminatum with significant neurological involvement, he received cladribine therapy and showed significant improvement in both cutaneous and nervous system lesions.

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.

The color of skin: orange diseases of the skin, nails, and mucosa.

Cutaneous disease can present with lesions of all colors of the visible spectrum. Lesions of the skin, nail, and mucous membranes with an orange color can be due to a variety of etiologies. The conditions may appear as purely orange, yellow-orange, red-orange, tan, or brown with an orange hue. The orange color may also present as a transient phase of a disease process. As with all dermatologic pathology, a key way to distinguish orange-colored lesions is by distribution and morphology. The sclera, palate, lips, gingiva, and nails may also be involved. A literature review using PubMed with keywords, including orange, skin, mucosa, cutaneous, xanthoderma, and granuloma, was conducted to gather all dermatologic conditions that can present with an orange color. The relevant diseases were categorized by etiology and include inflammatory, infectious, neoplastic, and exogenous causes.

Multicentric Reticulohistiocytosis with Dermatomyositis-like Eruptions.

A 68-year-old man presented with polyarthritis, proximal muscle weakness, and erythema of the face, arms, neck, and anterior chest that resembled the V-neck sign. Initially, dermatomyositis (DM) was considered because of the erythema, polyarthritis, and muscle weakness. He also had mediastinal and hilar lymphadenopathy on contrast-enhanced computed tomography. Unexpectedly, a biopsy of the forehead skin revealed numerous multinucleated giant cells. A biopsy of a solitary nodule on the dorsum of his right middle finger revealed similar multinucleated giant cells with ground-glass cytoplasm, leading to the diagnosis of multicentric reticulohistiocytosis (MRH). Although MRH is rare, it should be remembered that MRH can mimic DM.

High prevalence of myeloid neoplasms in adults with non-Langerhans cell histiocytosis.

Erdheim-Chester disease (ECD) is a rare non-Langerhans cell histiocytosis that most commonly affects adults and is driven by a high frequency of mutations in BRAF, MAP2K1, and kinases promoting MAPK signaling. Because of the relative rarity of ECD, key clinical features of the disease may not be well defined. Across a multi-institutional cohort of 189 patients with ECD and ECD overlapping with Langerhans cell histiocytosis (so-called mixed histiocytosis [MH]), we identified an unexpected and heretofore undescribed frequent occurrence of myeloid neoplasms among patients with ECD and MH. Some 10.1% (19/189) of patients with ECD have an overlapping myeloid neoplasm, most commonly occurring as a myeloproliferative neoplasm (MPN), myelodysplastic syndrome (MDS), or mixed MDS/MPN overlap syndrome (including chronic myelomonocytic leukemia). Consistent with this, molecular analysis frequently detected hallmark driver mutations of myeloid neoplasms (such as JAK2V617F and CALR mutations) coexisting with those characteristic of histiocytosis (such as BRAFV600E and MAP2K1 mutations). Histiocytosis patients diagnosed with a concomitant myeloid malignancy were significantly older at diagnosis and more commonly presented with MH than those without a myeloid malignancy. In some cases, the presence of distinct kinase mutations in the histiocytosis and myeloid neoplasm resulted in discordant and adverse responses to kinase-directed targeted therapies. These data highlight the clinical importance of evaluating adults with histiocytosis for a concomitant myeloid neoplasm.

The clinical spectrum of xanthomatous lesions of the eyelids.

Yellowish papules, nodules, or plaques, namely "xanthomatous" lesions, may be seen on the eyelids in the course of various disorders. The prototype is "xanthelasma palpebrarum" (XP) that is localized only to the eyelids and may be associated with hyperlipidemia. On the other hand, different types of normolipemic disorders may also cause xanthomatous eyelid lesions. Among these, Langerhans cell histiocytosis, diffuse normolipemic xanthoma, and non-Langerhans cell histiocytoses (papular xanthoma, juvenile xanthogranuloma, xanthoma disseminatum, adult-onset xanthogranuloma, adult-onset asthma and periocular xanthogranuloma, necrobiotic xanthogranuloma, Erdheim-Chester disease, Rosai-Dorfman disease, and reticulohistiocytosis) can be listed. The eyelid findings of this heterogeneous group of disorders are challenging to differentiate from each other due to common clinical aspects that may even sometimes mimic XP. Nodularity, induration, ulceration, diffuse eyelid involvement, and extension from eyelids to the neighboring skin may represent the clinical features of xanthomatous lesions other than XP. It is necessary to obtain a thorough history and exclude XP and then perform detailed dermatological and systemic examination, biopsy for histopathologic confirmation, and appropriate specific imaging screens. As some of the conditions may be associated with other systemic disorders, especially malignancies, the differentiation of xanthomatous eyelid lesions has a critical importance, and clinical signs can be guiding.

Xanthoma Disseminatum in a Young Patient with Diabetes Insipidus.

Xanthoma disseminatum (XD) is a nonfamilial type of normolipidemic mucocutaneous xanthomatosis that belongs to the group of non-Langerhans cell histiocytoses. More than 100 cases of XD have been reported. In this study we report a case of XD in a 4-year-old boy with diabetes insipidus (DI). This boy is one of the youngest patients ever to present with XD combined with DI.