Objective: To evaluate whether patients with inclusion body myositis (IBM) can have tubuloreticular inclusions present in muscle endothelial cells.
Material and methods: Light microscopy with histochemical staining and electron microscopy of a right quadriceps muscle biopsy were used to identify the pathological features in an 83-year-old patient with a clinical diagnosis of IBM.
Results: Light microscopy showed rimmed vacuoles. Immunostaining for HLA-1 revealed widespread membrane labeling and for TDP-43 multiple areas of subsarcolemmal and sarcoplasmic staining. Electron microscopy revealed tubuloreticular inclusions in the cytoplasm of endothelial cells. Electron microscopy also showed the presence of myeloid bodies and aggregates of tubolo filaments in the nucleus and cytoplasm of myocytes which confirmed the diagnosis of inclusion body myositis.
Conclusion: Tubuloreticular inclusions may be found in the muscle endothelial cells of patients with a clinical and pathological diagnosis of IBM.