대한흉부영상의학회 Korean Society of Thoracic Radiology

Discussion

Diagnosis With Brief Discussion

Diagnosis

Langerhans cell histiocytosis

Radiologic Findings

Chest radiograph finding was nonspecific. There was a new, small lobulated nodule, measured 8 mm in axial diameter located in the right middle lobe. This nodule did not exist 6 months ago. He was a smoker of 30 pack-years. This patient does not have any history of malignancy. PET-CT was obtained to find hidden malignancy. A very weak uptake was seen in the lung nodule, along with another uptake in T5 vertebral body.
CT and T-spine MRI correlation: A single osteoblastic nodule in the T5 vertebral body. There was about 1.7cm sized T1 and T2 low, Gd-enhancing mass on MRI. VATs wedge resection was done for lung nodule, and Langerhans cell histiocytosis was confirmed.

Brief Review

Langerhans cell histiocytosis (LCH) is an uncommon disease. Several synonyms, including histiocytosis X, eosinophilic granuloma, and Langerhans cell granulomatosis, have been used in the past, but the term Langerhans cell histiocytosis is now preferred. Despite the strong association with smoking, pulmonary LCH remains an uncommon disease, and accurate data of incidence and prevalence are problematic. With the widespread use of high-resolution CT today such surgical lung biopsy is performed much less frequently, and the diagnosis often is made based on a combination of clinical and imaging findings.
The high-resolution CT features in early disease are multiple ill-defined micronodules (1–5 mm in diameter) with a bronchiolocentric (centrilobular) distribution. Nodules may be profuse and predominate in the upper and middle lung zones with typical sparing of the costophrenic angles and tips of the lingula and right middle lobe. A lower zone predominance is unusual but has been described. Larger nodules (>1 cm in diameter) also can be seen and may warrant follow-up to evaluate for malignancy. Rarely, a solitary pulmonary nodule may be the only manifestation. As the disease progresses the nodules tend to cavitate, and a combination of cysts and nodules is characteristic. The distribution of cysts is the same as that of nodules, and the craniocaudal distribution of abnormalities may be convincingly shown on coronal and sagittal reformats. Recent studies have shown that positron emission tomographic (PET) scanning is a useful imaging modality to determine the extent of disease involvement in affected patients. Positive PET scans in pulmonary LCH usually occur in predominantly nodular lung disease, thick-walled cysts, bone, liver, and other extrapulmonary sites of involvement.

References

1. Muller’s imaging of the chest, Elsevier, p494-501

Please refer to

Case 1259 Case 1217 Case 980 Case 904 Case 849 Case 717 Case 680 Case 654 Case 587 Case 422 Case 367 Case 226

Keywords

Langerhans Cell Histiocytosis,