A H & E stain |
What is the most likely diagnosis? Answer: Perifascicular atrophy of muscle fibers is typical of dermatomyositis. |
B H & E stain |
How would you interpret this finding? Answer: The perivascular infiltrate is suggestive of a systemic autoimmune disorder. There are no myopathic changes to support a diagnosis of myositis. |
C Alkaline phosphatase stain |
How would you interpret this pattern of alkaline phosphatase staining of the perimysium? Answer: Alkaline phosphatase staining of muscle connective tissue supports a diagnosis of an immune mediated myopathy |
D H & E stain |
How would you interpret this finding? What other stains might be performed to clarify the disease process? Answer: Focal invasion of muscle fibers by inflammatory cells is common in polymyositis and inclusion body myositis. The cells are commonly labeled by Acid phosphatase and Non-specific esterase. |
E Congo red stain |
What does this pattern of inflammation suggest? What additional stains would be useful to confirm your impression? Answer: Most of the cells in the center of this granuloma stain with esterase and acid phosphatase. |
F H&E stain |
What does this pattern of inflammation suggest? What additional stains would be useful to confirm your impression? Answer: Selective inflammation in the perimysium commonly occurs in fasciitis. The cells often stain with esterase and acid phosphatase. |
G H&E stain |
What does this pattern of inflammation suggest? What additional tests would be useful to confirm your impression? Answer: The dark mononuclear cells are probably lymphocytes forming a lymphorrhage. The biopsy is from a patient with myasthenia gravis and thymoma. |