---

Trunk Muscles

---

H&E stain

Fiber size: Mild variation
Endomysial connective tissue: Normal
Perimysial Vessels: Normal

H&E stain

Congo red stain

Nuclei: Normally present at periphery of muscle fibers

---

Gomori trichrome stain

Internal architecture: Mildy prominent or coarse

VvG stain

---

Internal architecture

NADH stain

Internal architecture   Varied degrees of coarseness & irregularity   "Alveolar" fibers: Similar to those seen in CACNA1S congenital myopathy NADH stain

Some muscle fibers have
  Internal clear regions
  Irregular internal architecture

NADH stain

---

ATPase pH 9.4 stain

Fiber types
  Some fascicles, or entire muscles, can have marked type I fiber predominance
  Fiber type proportions can vary among fascicles

ATPase pH 9.4 stain

---

No fiber type grouping

ATPase pH 9.4 stain

---

Alkaline phosphatase stain

Endomysial capillaries
  Some, more than in limb muscles, stain for alkaline phosphatase

Alkaline phosphatase stain

---

Muscle: Other Structures

Muscle structures
  Vessels
    Arteries: Fibrillar internal layer
    Veins: (Black arrows): Wall may have no fibrils (Above) or many curved fibrils (Below)
    Endomysial capillaries (White arrow)
  Spindle (Contains small round muscle fibers)
  Intramuscular nerve (Myelinated axons are dark-stained)
  Perimysium: Connective tissue between fasciclas (Pink-stained): Contains irregular fibrils
    Vascular perimysium: Contains intermediate-sized arteries & veins + lymphatics
    Avascular perimysium: Contains no vessels

---

Avascular Perimysium

---

Return to Pathology index
Return to Neuromuscular Home Page

5/10/2020