CENTRONUCLEAR (MYOTUBULAR) MYOPATHY

• Central nuclei
  • Clustered central nuclei: Bin1
• Central muscle fiber staining
  • DHPR: MTM1; Bin1
  • RYR1: MTM1; DNM2; Bin1
  • Desmin: MTM1; DNM2; Bin1
  • Caveolin-3: Bin1
  • Histochemistry, punctate: DNM2
• Radiating sarcoplasmic strands (NADH): DNM2
• Necklace fibers: MTM1, late onset

Centronuclear myopathy: Infantile

From: T Mozaffar
H&E stain	H&E stain

H&E stain

H&E stain

Toluidine blue stain

Toluidine blue stain

Toluidine blue stain

Toluidine blue stain

Electron microscopy from T Mozaffar

ATPase stain, pH 9.4

ATPase stain, pH 9.4

NADH stain

NADH stain

NADH stain

Centronuclear myopathy: Childhood H&E stain	H&E stain
Central nuclei in several smaller muscle fibers. Central regions in other fibers are basophilic.
NADH stain	ATPase stain, pH 9.4
Abnormal internal architecture. Some fibers have central dark staining. Others have coarse internal architecture.	Type I (light) muscle fibers tend to be smaller than type II. Clear regions in center of type 1 fibers.

Centronuclear myopathy: Juvenile with Necklace fibers
H&E stain	ATPase stain, pH 9.4	NADH stain
Central nuclei in several smaller muscle fibers.	Type I (light) muscle fibers are generally smaller than type II (dark) fibers. Clear regions in center of type I fibers.	Abnormal internal architecture in smaller (type I) muscle fibers.

H&E stain

Bimodal distribution of muscle fiber sizes Central nuclei, especially in smaller fibers Clefts in center of other muscle fibers H&E stain

Gomori trichrome stain

Central nuclei, especially in smaller fibers Clefts in center of other muscle fibers Rings (Necklaces) in some muscle fibers Gomori trichrome stain

NADH stain Necklace fibers

ATPase pH 9.4 stain

Most small muscle fibers are type 1 ATPase pH 4.3 stain

Esterase stain

Centronuclear myopathy: Juvenile with many Central nuclei & Type 2C fibers

H&E stain

Many muscle fibers have single central nuclei H&E stain

VvG stain

NADH stain Abnormal internal architecture around central nuclei

ATPase pH 9.4 stain

ATPase pH 4.3 stain Many abnormal, intermediate-staining (type 2C), muscle fibers

Centronuclear myopathy: Juvenile with Small muscle fibers & Punctate central NADH stain

H&E stain

Many muscle fibers have single central nuclei H&E stain stain

NADH stain Punctate central staining in many muscle fibers

ATPase pH 9.4 stain

Type 1 muscle fibers are smaller than typ2 2 ATPase pH 4.3 stain