A Case of Nonsmoker Pulmonary Langerhans Cell Histiocytosis With Multiple Pulmonary Nodules Disappeared and Appeared.

We present a non-smoker woman in her 40s with PLCH who presented with atypical imaging findings of multiple pulmonary noncavitary nodules without air cysts with repeated waxing and waning.

Osteosarcoma and Langerhans Cell Histiocytosis in a Pediatric Patient with Lynch Syndrome: A Case Report.

CASE: Lynch syndrome (hereditary nonpolyposis colorectal cancer) is associated with extracolonic manifestations, but skeletal tumors are rare. Our patient, a 12-year-old boy with Lynch syndrome, developed osteosarcoma of the left femur. Treatment included cytotoxic chemotherapy, wide resection, and pembrolizumab. Two years later, he developed an aggressive lesion in the contralateral femur that was thought to be metastatic osteosarcoma but which histology revealed to be Langerhans cell histiocytosis. CONCLUSION: This case underscores the importance of advanced testing in patients with osteosarcoma and poor response to chemotherapy, and of tissue sampling when patients with a primary malignancy develop new bone lesions. LEVEL OF EVIDENCE: IV.

68 Ga-FAPI and 18 F-FDG PET/CT Imaging in Langerhans Cell Histiocytosis for Recurrence and Therapeutic Response Assessment.

ABSTRACT: A 2-and-a-half-year-old boy with a previous history of Langerhans cell histiocytosis reached remission as assessed by 18 F-FDG PET/CT. Routine follow-up 18 F-FDG PET/CT revealed the appearance of new bone lesions in the right scapula and right ischium with abnormal FDG activity 3 months after the end of treatment, and Langerhans cell histiocytosis recurrence was considered. Meanwhile, these lesions also showed increased FAPI uptake. After adjusting the chemotherapy regimen, both FDG and FAPI uptake almost disappeared in these lesions.

Langerhans cell histiocytosis in sphenoid sinus with vision impairment: Case report and literature review.

Langerhans cell histiocytosis (LCH) is a neoplastic disease characterized by aberrant proliferation of the mononuclear phagocyte system, predominantly affecting children under the age of 3 years. Although LCH can affect almost all organs, sinus involvement is rare. This case report documents a 9-year-old boy presented with vision impairment and intermittent headache on the right side. The CT scan and MRI examination revealed the presence of a soft mass in the right atrium of sphenoid sinus, which impacted the right optic canal. Biopsy results confirmed the presence of LCH. Considering the involvement of optic canal and vision impairment, meticulous debridement was performed followed by a 12-month standard chemotherapy. After 2 years of follow-up, the patient showed significant improvement, despite the presence of an encapsulated cyst in the right sphenoid sinus. This case highlights the importance of considering LCH when encountering an isolated soft mass accompanied by decreased vision in the sphenoid sinus. A thorough physical examination, laboratory tests, and imaging methods should be performed, with a biopsy being necessary to confirm the type of lesion and guide the appropriate treatment.

Langerhans Cell Histiocytosis of the Nasal Mucosa.

This case report describes a female patient in her early 40s with left-sided cervical lymphadenopathy, facial swelling, nasal congestion, and a left nasal mass.

Langerhans cell histiocytosis mimicking acute dacryocystitis.

Langerhans cell histiocytosis (LCH) is a myeloid neoplasm characterized by clonal neoplastic proliferation of Langerhans-type dendritic cells associated with an inflammatory infiltrate predominantly composed of lymphocytes and eosinophils. In this article, we present an unusual case of LCH with significant swelling in the left lacrimal sac region in a 3-year-old child, clinically mimicking acute dacryocystitis. Microscopically, it showed intense inflammatory infiltrate and histiocytes with irregular nuclei. The tumor cells were positive for S-100 protein, CD1a, and CD207 (langerin). Molecular study was positive for the V600E/E2/D mutation (EXON 15). This case emphasizes the importance of careful clinical, radiographic, and microscopic evaluation, as some neoplasms may mimic common benign lesions.

Langerhans cell histiocytosis of the suprasellar region: diagnosis based on thyroid cytology.

Langerhans cell histiocytosis (LCH) may present as unifocal disease of the suprasellar region, with symptoms and signs of hypopituitarism, arginine vasopressin deficiency (AVP-D), and weight gain. Transcranial biopsy is necessary to define diagnosis and guide treatment decisions, but it is associated with significant morbidity. We describe a patient with Hashimoto thyroiditis and a single hypothalamic mass in whom LCH diagnosis was made by thyroid fine-needle aspiration cytology (FNAC) performed despite nonspecific findings in thyroid imaging, on the basis of a slightly elevated [18F]-fluorodeoxyglucose (FDG) avidity on PET/CT and volume increase during follow-up.

Langerhans cell histiocytosis of the sella in a pediatric patient: case report with review of the literature.

PURPOSE: Langerhans cell histiocytosis (LCH) is a rare condition arising from the monoclonal expansion of myeloid precursor cells, which results in granulomatous lesions that characteristically express CD1a/CD207. We report a case of LCH in a 3-year-old male involving the sphenoid bone with extension into the sellar/suprasellar region. CASE REPORT: A 3-year-old male presented with progressively worsening headaches and associated night sweats, neck stiffness, and fatigue over the previous 4 weeks. Magnetic resonance imaging (MRI) revealed a 2.4-cm lytic lesion within the basisphenoid, exerting mass effect upon the pituitary gland. A biopsy was performed to determine the etiology of the lesion. Postoperatively, the patient developed an intralesional hematoma with visual complications requiring emergent surgical resection via endoscopic endonasal approach. Final pathology confirmed LCH. The patient had improvement in his vision long term. CONCLUSIONS: LCH extending into the sella is a rare but important diagnosis to consider in pediatric patients presenting with lesions in this region. We presented a case of a pediatric patient presenting with LCH of the sphenoid bone extending into the sella, with subsequent apoplexy and vision loss. Review of the literature showed varying treatment options for these patients, including purely surgical and non-surgical treatments. Early intervention may be necessary to avoid potentially devastating neurologic sequelae.

Juvenile xanthogranuloma manifesting with LCH-associated neurodegenerative disease-like radiological findings.

Here, we describe two patients with juvenile xanthogranuloma (JXG) manifesting with Langerhans cell histiocytosis (LCH)-associated neurodegenerative disease (ND)-like radiological findings. One patient showed typical radiological abnormalities at onset, which worsened with progressing central nervous system symptoms 7 years after LCH-oriented chemotherapy. Another showed spontaneous regression of clinical symptoms, with a transient radiological change 1 year after salvage chemotherapy for recurrence of JXG. These data regarding JXG-associated ND will facilitate future investigation of the disease, as well as development of therapeutic interventions.

Langerhans cell histiocytosis involving the temporal bone with destruction and subsequent reossification of the bony labyrinth boundaries.

PURPOSE: With an incidence between 1-9/100 000 per year, Langerhans cell histiocytosis (LCH) is a rather rare disease from the hemato-oncologic disease spectrum (Hayes et al. 2009). The tumorlike disease with proliferation of histiocytic cells may manifest as localized to one organ or disseminated with infiltration of a wide variety of organs. Approximately 25-30 % of these cases show involvement of the temporal bone (Ni et al. 2017). CASE DESCRIPTION: With vertigo persisting for three years, chronic mastoiditis, and acute progressive hearing loss bilaterally (r > l) for three weeks, a 41-year-old woman presented at an emergency department. The DVT showed extensive bony destruction of large parts of the temporal bone on both sides, involving the vestibular organ, the cochlea, and the internal auditory canal. To confirm the suspicion of a systemic inflammatory process, a PE was performed from the mastoid with bioptic confirmation of an LCH. Systemic therapy was initiated. Post-therapeutic imaging showed almost complete remission with reossification of the preexisting defect zones and the internal auditory canal and labyrinth structures again showed bony margins. Clinically, there was an improvement of the vegetative symptoms with remaining bilateral sensorineural hearing loss. DISCUSSION: LCH of the temporal bone is a rare and often misdiagnosed disease due to its nonspecific clinical presentation. Awareness of temporal bone LCH and its occurrence in adults is essential for accurate and consistent diagnosis. KEY POINTS: · LCH is a rather rare disease from the hemato-oncological spectrum. · Affection of the temporal bone, especially such an extensive one (as in this case report), is rather atypical in adulthood. · Use of systemic therapy resulted in remission. · There was complete reossification of the osseous structures post-therapy. · A cochlear implant was able to be implanted to compensate for hearing loss.

Coexistence of Langerhans Cell Histiocytosis and Ganglioneuroblastoma Revealed by 18 F-FDG PET/CT in a Pediatric Patient.

ABSTRACT: Coexistence of Langerhans cell histiocytosis and ganglioneuroblastoma is rare and seldom reported in the literature. A 3-year-old girl with Langerhans cell histiocytosis underwent 18 F-FDG PET/CT imaging for staging, which demonstrated significant 18 F-FDG accumulation in the mandibles. Unexpectedly, a mild hypermetabolic soft mass was detected in the upper retroperitoneum. Results of surgical pathology of the abdominal mass were consistent with ganglioneuroblastoma.

The value of 18F-FDG PET/CT in Langerhans cell histiocytosis.

OBJECTIVE: To investigate the value of 18F-FDG PET/CT in diagnosis and disease evaluation of Langerhans cell histiocytosis (LCH). METHODS: A retrospective analysis of 31 patients with LCH confirmed by histopathology was performed. A systematic analysis of the PET/CT imaging manifestations of LCH was performed, recording patients who were treated and receiving PET/CT for efficacy evaluation. In addition, clinical and laboratory data of LCH patients were collected, and the correlation between these data and PET/CT metabolic parameters was initially investigated. RESULTS: Of the 31 patients, thirty had at least 1 PET/CT positive lesions (96.7%), and one had only skin damage without abnormalities on PET/CT. Of 31 patients, fifteen (48.4%) had single system (SS) disease (9 cases with a single site and 6 cases with multiple sites) and 16 (51.6%) had multisystem (MS) disease (6 low risk and 10 high risk cases). The incidence of LCH lesions in the bone, lymphatic system, pituitary gland, liver, soft tissue, thyroid gland, thymus, and lungs was 20 cases (64.5%), 12 cases (38.7%), 3 cases (9.7%), 2 cases (6.5%), 2 cases (6.5%), 1 case (3.2%), 1 case (3.2%), and 8 cases (25.8%), respectively. A total of 21 PET/CT follow-up scanning were performed in 13 patients receiving chemotherapy, with 13 (61.9%) partial metabolic remission (PMR), 6 (28.6%) progressive metabolic disease (PMD), and 2 (9.5%) stable metabolic disease (SMD), according to PET Response Evaluation Criteria in Solid Tumors (PRECIST) 1.0. Erythrocyte sedimentation rate (ESR), C-reactive protein (CRP) and Lactic Dehydrogenase (LDH) were positively correlated with TTLG (total TLG) (R2 = 0.3256, 0.2409, 0.4205, P < 0.05). The Re-examine SUVmax is positively correlated with re-examine LDH (R2 = 0.7285, P < 0.05). CONCLUSIONS: 18F-FDG PET/CT is an effective way to diagnose and evaluate LCH. PET metabolic parameters were associated with laboratory inflammatory markers, suggesting that 18F-FDG PET/CT may be helpful in evaluating disease activity of LCH.

Langerhans cell histiocytosis of the thyroid mimicking thyroiditis in a boy: a case report and literature review.

BACKGROUND: Langerhans cell histiocytosis affecting the thyroid commonly presents with nonspecific clinical and radiological manifestations. Thyroid Langerhans cell histiocytosis is typically characterized by non-enhancing hypodense lesions with an enlarged thyroid on computed tomography medical images. Thyroid involvement in LCH is uncommon and typically encountered in adults, as is salivary gland involvement. Therefore, we present a unique pediatric case featuring simultaneous salivary and thyroid involvement in LCH. CASE PRESENTATION: A 3-year-old boy with complaints of an anterior neck mass persisting for 1 to 2 months, accompanied by mild pain, dysphagia, and hoarseness. A physical examination revealed a 2.5 cm firm and tender mass in the left anterior neck. Laboratory examinations revealed normal thyroid function test levels. Ultrasonography revealed multiple heterogeneous hypoechoic nodules with unclear and irregular margins in both lobes of the thyroid. Contrast-enhanced neck computed tomography revealed an enlarged thyroid gland and bilateral submandibular glands with non-enhancing hypointense nodular lesions, and multiple confluent thin-walled small (< 1.5 cm) cysts scattered bilaterally in the lungs. Subsequently, a left thyroid excisional biopsy was performed, leading to a histopathological diagnosis of LCH. Immunohistochemical analysis of the specimen demonstrated diffuse positivity for S-100, CD1a, and Langerin and focal positivity for CD68. The patient received standard therapy with vinblastine and steroid, and showed disease regression during regular follow-up of neck ultrasonography. CONCLUSIONS: Involvement of the thyroid and submandibular gland as initial diagnosis of Langerhans cell histiocytosis is extremely rare. It is important to investigate the involvement of affected systems. A comprehensive survey and biopsy are required to establish a definitive diagnosis.