A rare imaging presentation with multisystemic clinicopathological features of Langerhans cell histiocytosis: Case report and literature review

RATIONALE: Langerhans cell histiocytosis (LCH) is a kind of rare disease in which dendritic cells proliferate abnormally. It often occurs in children and can involve any tissue and organ. The affected sites usually include bone, skin, pituitary gland, and lungs, while the thyroid gland and external auditory canal are rarely observed. The perineal and labial involvement of this disease has not been reported yet. PATIENT CONCERNS: A 47-year-old female patient experienced a swelling of the anterior neck area without an obvious inducement. She noticed a quail egg-like mass on the left side, and the mass increased progressively within 3 months. The anterior neck area was found to be swollen, and some flaky red rashes were seen on the scalp and bilateral external auditory canals. DIAGNOSES: Imaging examination showed enlarged thyroid and cervical lymph nodes, multiple low-density nodules in the liver, and reduced signal in the posterior pituitary gland. The biopsy pathological result of the increased left cervical lymph node indicated that LCH was detected. INTERVENTIONS: VP regimen (vincristine, dexamethasone per os) and related supportive treatments were given as inducing chemotherapy for 6 weeks. OUTCOMES: After the second chemotherapy, the rash on the scalp and external auditory canal improved, and the neck mass was significantly reduced. After the third chemotherapy, the rash was mostly disappeared, while the neck lumps increased during chemotherapy. Thus, clatribine chemotherapy was recommended as the follow-up. LESSONS: Imaging examinations played an important role in the diagnosis and follow-up of the disease, especially (18)F-FDG PET/CT, which could show multiple involving organs at the same time. When a patient suffering from diabetes insipidus, skin rash, or fever, has a high FDG uptake PET/CT result in multiple tissues and organs throughout the body, it is necessary to consider the possibility of LCH.