Kenyan nodular lymphocyte predominant Hodgkin lymphoma shares features with western cases and is not associated with EBV

Document Type



Pathology (East Africa)


Background: Pulmonary Langerhans cell histiocytosis (PLCH) is a distinctive form of tobacco associated interstitial lung disease. Therapeutic options other than lung transplantation are scarce when a fibrotic phase has been reached. One severe complication is the emergence of pulmonary hypertension that has been related to chronic hypoxia. A few papers describe its morphological characteristics focusing on arterial lesions. Otherwise, BRAF mutations have been recently described in systemic Langerhans cell histiocytosis and only one paper with five cases has been published on PLCH. Methods: We have revised morphological changes associated with pulmonary vasculature and the presence of Langerhans cells by routine and immunohistochemical methods (S100 protein, CD1a and Langerin) in 22 PLCH cases. We have used real time PCR to detect BRAF mutations in Langerhans cells using manual macrodisection in paraffin embedded tissue. Results: Six out of 22 patients (27%) showed some grade of capillary haemangiomatosis-like changes. Aggregates of Langerhans cells were located in interlobular septa in those cases. Two BRAF mutated cases were found, both of them in cellular/mixed lesions. Conclusion: We present six patients with capillary haemangiomatosis-like changes with infrequent located Langerhans cells in pulmonary Langerhans cell histiocytosis. We confirm the occurrence of BRAF mutations in this kind of disease.