A 34 year old male with predominantly distal weakness, atrophy and myotonia. Cecile L. Phan, M.D., F.R.C.P.C. Eddie L. Patton, M.D. Yadollah Harati, M.D., F.A.C.P. Clinical History. 34 yo RHD male presented with complaint of muscle atrophy and weakness affecting the hands and feet.
A 34 year old male with predominantly distal weakness, atrophy and myotonia
Cecile L. Phan, M.D., F.R.C.P.C.
Eddie L. Patton, M.D.
Yadollah Harati, M.D., F.A.C.P.
H&E: Marked increased variability in fiber size and shape. Most fibers appear rounded. Clusters of rounded, small fibers as well as hypertrophic fibers (up to 152 microns) are seen. Increased endomysial connective tissue is also observed.
H&E: several fibers contain one or several rimmed vacuoles
H&E: rimmed vacuole with granular material lining the vacuole
ATPase 9.4: atrophic and hypertrophic fibers of both fiber types. The vacuoles are often seen in clusters of atrophic fibers.
NADH (left) and non-specific esterase (right): atrophic, angular fibers with excessive NADH and non-specific esterase activity indicative of neurogenic atrophy
SMI 31: SMI 31 positive aggregates seen in the cytoplasm of a non-vacuolated fiber (arrow, left figure) and diffuse increase in the cytoplasm of some atrophic fibers (right figure
Hereditary Inclusion Body Myopathy type 2
*Barohn RJ, Watts GD, Amato AA. A case of late onset proximal and distal muscle weakness. Neurology 2009; 73 (19):1592-1597
Sialic acid is present on distal ends of N- and O-glycans and involved in many biological functions
BMC Neurology 2007, 7:3