2026-07-06 | Enigmatic Case of Adult-Onset Langerhans Cell Histiocytosis with Aggressive Bony Involvement.
Langerhans cell histiocytosis (LCH) is a rare hematologic neoplasm predominantly affecting children, with adult-onset cases being exceedingly uncommon. Neurological presentations, including spinal cord compression and cranial neuropathies, represent atypical manifestations that often lead to diagnostic delays. We present a 20-year-old previously healthy female who presented with progressive back pain, bilateral lower extremity weakness, and left-sided hearing loss. Imaging revealed a thoracic epidural mass causing severe spinal stenosis with additional diffuse osteolytic lesions. Initial biopsies showed nonspecific lymphoplasmacytic infiltrates. The patient subsequently developed cranial nerve palsies and dysphagia over several months. Definitive diagnosis required three biopsies, with the final petrous bone specimen demonstrating characteristic LCH histology and positive immunostaining for CD1a, S100, and Langerin. Treatment with zoledronic acid failed; subsequent therapy with cytarabine followed by cladribine plus hydroxyurea achieved partial radiographic and clinical improvement, though complicated by treatment-related sepsis. This case highlights the diagnostic and therapeutic challenges of adult LCH, given its rarity, variable presentation, and limited treatment guidelines. Multiple tissue samples with appropriate immunohistochemical staining may be required for diagnosis. Adult LCH treatment remains empirical, often extrapolated from pediatric data, with systemic therapies carrying significant toxicity risks. Greater awareness and adult-specific clinical trials are urgently needed.
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2026-07-03 | Intralesional corticosteroid injections in single-system Langerhans cell histiocytosis with maxillomandibular involvement: a systematic review.
Single-system Langerhans cell histiocytosis (LCH) involving the maxillomandibular complex is rare, and optimal management remains controversial. Intralesional corticosteroid injections have been proposed as a minimally invasive alternative to surgery, radiotherapy, or systemic therapy. The aim of this study is to systematically evaluate the effectiveness and safety of intralesional corticosteroid injections for treating LCH of the maxilla or the mandible. A systematic review was conducted according to the PRISMA guidelines, in which PubMed, Embase and Scopus were searched. Eligible studies included English language case reports and case series describing LCH of the mandible and/or maxilla that had been confirmed by biopsy and treated with intralesional corticosteroid injections. Outcomes assessed included the resolution of symptoms, regression of lesions confirmed by radiography, recurrence, and adverse effects. Fifteen studies comprising 28 patients were included. Thirteen patients were treated with triamcinolone acetonide, 13 with methylprednisolone, and two with dexamethasone. Lesions were predominantly unifocal and located in the body or ramus of the mandible. Intralesional corticosteroid therapy was effective in 27 patients. Recurrence was reported in one case 12 months post treatment. Adverse effects were limited to one localised abscess that resolved without sequelae. Intralesional corticosteroid injections are associated with high rates of clinical and radiological improvement in mandibular and maxillary LCH, with minimal morbidity. While the current evidence is limited to low level studies, this approach represents a promising conservative treatment option. Prospective studies with standardised protocols are needed to define its long-term efficacy and role within treatment algorithms.
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2026-07-03 | Cytarabine-based induction and oral maintenance therapy for a single system with single-site Langerhans cell histiocytosis.
Single-system, single-site (SS-s) Langerhans cell histiocytosis (LCH) is usually managed with observation or local therapy; however, a subset of patients requires systemic chemotherapy, although the optimal intensity for this group remains unclear. In this study, we retrospectively reviewed patients with newly diagnosed or recurrent SS-s LCH who were treated at our institution. They received 6 weeks of induction chemotherapy with cytarabine, vincristine, and prednisolone, followed by 1 year of oral maintenance therapy with 6-mercaptopurine and methotrexate. Of these patients, 15 were evaluable (13 newly diagnosed and 2 recurrent). At the end of induction, all patients achieved a good or partial response and were administered maintenance therapy, after which they achieved a good response. With a median follow-up of 5.6 years, all patients were alive without subsequent relapse, death, or central nervous system (CNS) complications. No grade 3 or 4 nonhematologic toxicities were observed, except transient increases in liver enzymes during maintenance therapy. No adverse events occurred that required hospitalization. These results suggest that cytarabine-based induction followed by oral maintenance may be an effective and tolerable option for patients with SS-s LCH requiring systemic therapy.
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