A 70-year-old male patient has single well-defined lytic lesion of skull. The patient had no other complaint and urine examination had no abnormality. What is the most likely diagnosis? (AIIMS Nov 2018)
a. Unifocal Langerhans cell histiocytosis
b. Monoclonal Gammopathy of unknown significance
C. Multiple myeloma
d. Paget’s disease
Ans. (a) Unifocal Langerhans cell histiocytosis
The slide shows large number of histiocytes with excessively pink cytoplasm in all quadrants of the slide.
The nucleus of cells looks irregular like a coffee bean.
The clinical history of a single lytic bone lesion and histopathology points to the aetiology as Langerhans cell histiocytosis.