A one year old boy presented with hepatosplenomegaly and delayed milestones. The liver biopsy and bone marrow biopsy reyealed presence of histocytes with PAS positive. Electron microscopic examination of these histiocytes is most likely to reveal the presence of - (AIPG 2013)
|A||Birbeck granules in the cytoplasm|
|B||Myelin figures in the cytoplasm|
|C||Parallel rays of tubular structures in lysosomes|
|D||Electron dense deposit in the mitochondria|
Birbeck granules in the cytoplasm
a. Hepatosptenomegaly, presence of histiocytes with PAS postivesuggest the diagnosis of langerhans cell histiocyosis.
b. Diagnosis of LCH
i. The hallmark of LCE is clonal proliferation of cells of monocyte lineage'
ii. The presence of Birbeckgranales in the cytoplasm of tumor cells is characteristic of LCH.
iii. Birbeckgmnules are tennis racket shaped bilamellar granules-
iv. As Birbeck granules are not seen in all tumor cells by election microscopy, the detection of 5-100 and CD1a expression by immunohistochemical techniques makes the definitive diagnosis.