Skip to main content
. 2013 Jan 8;6:1–21. doi: 10.2147/CCID.S39017

Figure 2.

Figure 2

Figure 2

Figure 2

Figure 2

Figure 2

(A) Filament cross, oblique, and lateral sections, from a specimen collected from patient 1 showing round, elliptical/elongated, bean-like, or curved morphology. Note the hollow medulla and surrounding cortex. Cytokeratin (CK) AE1/AE3 staining. 100× magnification. (B) Specimen from patient 1, demonstrating irregular, patchy keratin staining with CK AE1/AE3, longitudinal section. Note most filaments staining positive for keratin (dark brown). 100× magnification. (C) Specimen from patient 1, demonstrating irregular, patchy keratin staining with CK AE1/AE3. Cross, oblique, and longitudinal sections. Note most filaments staining negatively for keratin. 400× magnification. (D) Longitudinal section of filament from patient 1. Note retained nuclei, central medulla, and patchy keratin staining with CK AE1/AE3. 400× magnification. (E) Sectioned filament from a specimen from patient 1, which upon gross microscopic examination demonstrated floral-like or stellate formations. Note retained nuclei within tentacle-like filaments with tapered ends. CK AE1/AE3 staining. 400× magnification. (F) Sectioned callus from patient 1, showing filaments stemming from the stratum basale with evolution inwards towards the dermis. Note filament sections with hollow medulla alongside the stratum basale. CK AE1/AE3 staining. 100× magnification. (G) Gömöri trichrome collagen-positive section of activated fibroblasts with filamentous inclusions from patient 2. Collagen stains green, keratin stains red. Growth of filaments was upwards toward the external surface. 400× magnification. (H) Ruptured keratin projection from both external and internal surfaces from a specimen collected from patient 2, with areas of fibroblast proliferation stained green. Gömöri trichrome stain. 100× magnification. (I) Section from patient 2 stained with Gömöri trichrome, demonstrating both keratin (red) and collagen (green) filament cross-sections, with most filaments associated with the external callus surface. 100× magnification. (J) Gömöri trichrome stain of specimen from patient 2, demonstrating filaments in longitudinal, oblique, and cross-sections close to and within collagen-positive fibroblast collections (green). Note presence of filament cross-sections staining positively for keratin (red). 400× magnification. (K) Bovine digital dermatitis (BDD) filament, longitudinal section, showing positive CK AE1/AE3 staining. 100× magnification. (L) BDD filament, longitudinal section, showing negative CK AE5/AE6 staining. 100× magnification.