S11C15P10-Infectious Diseases (misc)

S11C15P10-1: Along the superior margin, the interface of a circumscribed lesion with the dermis is represented; it is sharply defined. The lesion centrally is necrotic (caseous-type necrosis). The interface between viable and necrotic tissue is the zone between the green and blue arrows; this is a zone composed of epithelioid histiocytes in palisades. The lesion is a circumscribed, necrotic granuloma. A common site for this type of lesion is the hand. The lesion is a phaeohyphomycotic “abscess” ( a granuloma caused by pigmented fungi).

S11C15P10-2: The interface between viable and necrotic tissue is represented; it is composed of epithelioid histiocytes with scattered giant cells. Naturally, but faintly, pigmented organisms are present in the granuloma at the tips of the green arrows.

S11C15P10-3: At the tips of the green arrows, branching, pigmented organisms are represented.

S11C15P10-4: The organisms are PAS +. The pleomorphism is a characteristic of organisms in phaeohyphomyocotic “abscesses.”

 

S11C15P10-5: This is another field showing PAS +, pleomorphic organisms. Hyphae distinguish the organisms from those of chromomycosis.

S11C15P10-6: This is another example of a phaeohyphomycotic abscess with a cavity containing inflammatory cells to the right of the field. A hyphal form projects into the cavity (green arrow). The bright red fibers to the left of the organism are elastic fibers. The organism is not heavily pigmented. A Fontana-Masson stain is sometimes an aid in demonstating the presence of pigmented organisms.

S11C15P10-7: With a PAS stain, the organisms show marked pleomorphism.

S11C15P10-8: With a Gomori silver methenamine stain, the organisms show pleomorphism.

 

UP TO TEXTUAL LEVEL, IF AT PICTORIAL LEVEL (3), OR TO HOME IF AT TEXTUAL LEVEL (2)

BACK IN SPATIAL SEQUENCE ALONG TIER

Beige buttons to the right are a continuation of the vertically oriented beige cluster above. The mauve buttons provide access to other SECTIONS on this site.

NEXT CHAPTER IN SEQUENCE, IF AT EITHER LEVEL 2 OR LEVEL 3