Perivascular infiltrate

Various syndromes associated with hypereosinophilia involve skeletal muscle. There is a rare form of polymyositis which is characterized by this feature (defined as exceeding 1,500 eosinophils/mm for at least six months). Clinical presentation includes skin changes, heart and lung involvement, and peripheral neuropathy as well as proximal myopathy. The condition must be distinguished from trichinosis and other parasitic infections associated with hypereosinophilia. Muscle biopsy findings are interstitial and perivascular infiltrates in which eosinophils predominate but are accompanied by lymphocytes and plasma cells, and occasional muscle fiber necrosis. Fascitis may also be associated with hypereosinophilia (Shulman s syndrome). This condition is characterized by painful swelling of skin and soft tissues of trunk and extremities and weakness of limb muscles. Biopsy of muscle... 

An 86-year-old Japanese man received a pacemaker for atrioventricular block, and 2 months later developed a scaly erythema over the implantation site and later widespread nummular eczema. Histologically, the lesions showed slight spongiosis, intracellular edema, moderate acanthosis in the epidermis, and perivascular infiltration with thickened capillary walls in the dermis. The pacemaker contained titanium and a variety of other metals, but patch tests were all negative. However, titanium sensitivity was demonstrated by intracutaneous and lymphocyte stimulation tests. 

Other presentations include erythematous pruritic plaques associated with epidermal keratosis, focal spongiosis, and perivascular infiltrates of lymphocjdes and eosinophils or scleroderma-like hypodermic indurations (17). In such cases, intradermal tests may be positive for phjdonadione. 

Pathologic studies have demonstrated a perivascular, lymphocytic infiltrate with eosinophils in the dermis, fascia, and skeletal muscle, with variable numbers of eosinophils. The perivascular infiltrate was accompanied by thickening of the capillary and arteriolar endothelium in dermal, fascial, and muscle vessels. The frequent occurrence of microangiopathy (disease of the small blood vessels) in biopsy specimens suggests that ischemia (deficiency of blood supply) may contribute to tissue injury. Deposition of major basic protein (an eosinophil-specific protein) in affected tissue of some patients suggests that cytotoxic eosinophil degranulation products may also play a role in the pathogenesis of EMS. 

We have also observed in the guinea pig not only a diffuse infiltration with numerous preparations, but also perivascular infiltrates —. 

This pattern, found in some patients (40,41), was described as diffusely scattered centrilobular nodules (5 mm) within ground glass opacities in eight of nine patients investigated by Choi et al (39). These lesions, located in centrilobular spaces, correspond to pulmonary vasculitis and perivascular infiltration. 

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