Aspergillosis pathology

Introduction

Aspergillus species can cause invader cutaneous infections, particularly in immunosuppressed Hosts. the organism can be entered from local inoculation or reach the skin after dissemination from the lungs.

Histology aspergillosis

the inflammatory The pattern of fungal forms of aspergillosis depends on the depth of invasion and the immune status of the patient.

Sometimes fungal balls composed of numerous organisms forming a mass (figure 1), sometimes with fruitful heads (figure 2).

Most commonly, there is a dense acute infiltrate at dermis and deep Soft fabric (Figures 3, 4) that may be associated with necrosis and scars Organisms can sometimes be seen on close examination with routine HE staining (Figures 2, 4). With special stains, the morphology it is better appreciated and shows thin septate hyphae with regular branching (Figures 5, 6). The angle of the regular branch is approximately 450 (figure 5, arrow).

There may be angioinvasion, ulceration and extensive necrosis. In immune competent patients, a dense granulomatous The answer is common. Direct inoculation of the skin can cause scarring epidermal reply.

Special studies for aspergillosis.

The organisms can be easily seen in the hematoxylin and eosin sections (Figure 1). Special stains with PAS or GMS (Figure 2) can be used to highlight the organisms and allow a clearer assessment of morphology. Correlation with tissue cultures is helpful.

Differential diagnosis aspergillosis

Mucormycosis: Aspergillus species are thinner, septate, with regular branching and branching at acute angles compared to mucormycosis organisms (45 ° instead of 90 °).

Fusariosis, pseudallescheriosis: These organisms can have a morphology similar to aspergillosis, and generally require culture to allow a precise distinction.