case_images: PMC6801882_01
case_images: Clinical situation at first presentation at the age of 6 months, showing LCH
  and superinfection-affected upper jaw and prematurely erupted teeth.. LCH, Langerhans cell histiocytosis.
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case_images: A 6-month-old girl presented with gingival swelling and intraoral fibrinous coating along the alveolar crests of the maxilla (Figure 1) and mandible as well as feeding problems (700 ml/day, maximum 140 ml per portion).
case_images: Initial diagnosis of LCH via MRI: T2w TSE (a) and T1w FS
  after gadolinium administration (b) show manifestations in both sides of the
  maxilla and in the right mandible.. LCH, Langerhans cell histiocytosis; MRI, magnetic resonance imaging.
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case_images: During hospitalization in our clinic, an HN magnetic resonance imaging (MRI) scan with a contrast agent was performed (Figure 2) under general anaesthesia and showed up to 1-cm-broad T2w hyperintense and inhomogeneously contrast-enhancing lesions in the maxilla on both sides, reaching the scarcely pneumatized sinus.
case_images: Dental status after successful treatment with vemurafenib at the age of 3
  years, showing only a few remaining germs in the upper and lower jaw.
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case_images: As a result of persisting active LCH in the affected gingiva, further prematurely erupted teeth had to be removed, leaving only a few remaining germs of permanent teeth (Figure 3).
case_images: Extension of the disease in the craniofacial region after 2 years of
  conventional chemotherapy. Although T2w TSE FS MRI (a, c) and T1w TSE +
  gadolinium FS MRI (b, d, e) shows regression in the maxillary region (a, b),
  new manifestations are observed in the skull base, temporal region, and
  pituitary stalk and are still focused in the right mandible.. MRI, magnetic resonance imaging.
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case_images: Owing to relevant disease progression after almost 2 years of conventional LCH-III therapy with the newly diagnosed involvement of the skull, skull base, periorbital tissue [Figures 4 and 5(a)], temporal muscles on both sides, and pituitary stalk with resulting diabetes insipidus, the treatment regime was altered to a targeted approach, with the BRAF inhibitor vemurafenib as monotherapy owing to the BRAF V600E mutation found in primary tumour samples.
case_images: MRI scans showing pituitary involvement: (a) Coronal T1w TSE FS with contrast
  agent, where the arrow shows a thickened pituitary stalk; (b) Coronal T1w
  TSE FS with contrast agent showing normal pituitary stalk 3 months after
  initiation of treatment with vemurafenib; (c) T1w sagittal view after
  BRAF-specific therapy (without contrast agent): neurohypophysis is not
  delimitable after therapy (first complete remission); (d) T1w sagittal view
  after BRAF-specific therapy (with contrast agent): normal shape of pituitary
  stalk (first complete remission); (e) Normal neurohypophysis in a healthy
  patient: hyperintense signal in sagittal T1w without contrast agent.. MRI, magnetic resonance imaging.
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case_images: Owing to relevant disease progression after almost 2 years of conventional LCH-III therapy with the newly diagnosed involvement of the skull, skull base, periorbital tissue [Figures 4 and 5(a)], temporal muscles on both sides, and pituitary stalk with resulting diabetes insipidus, the treatment regime was altered to a targeted approach, with the BRAF inhibitor vemurafenib as monotherapy owing to the BRAF V600E mutation found in primary tumour samples. Ultrasound and MRI scans in routine check-ups showed improvement of the aforementioned lesions [Figure 5(b)]. After 1 year of treatment, MRI scans showed complete remission [Figures 5(c,d) and 6], and withdrawal from treatment was attempted.
case_images: T2w TSE FS (a) and T1w TSE + gadolinium FS (b) MRIs show a new lesion
  6 months after the cessation of treatment in the left zygoma.. MRI, magnetic resonance imaging.
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case_images: Unfortunately, the control MRI after 6 months showed new lesions in the left zygoma (Figure 7) as well as suspected infiltration of the pituitary gland and stalk.