This composite educational image illustrates the clinical, diagnostic, and dermoscopic features of onychomycosis. Panel A shows a clinical photograph of proximal subungual onychomycosis with a characteristic white/yellowish opacity at the lunula. Panel B depicts plantar desquamation (tinea pedis), a common co-infection. Panels C and D show laboratory diagnostics: a potassium hydroxide (KOH) mount with visible septate hyphae (200x) and a Grocott-Gomori methenamine silver (GMS) stained nail clipping (400x) where fungal elements appear black against a green background. Panels E and F provide dermoscopic views of distal lateral subungual onychomycosis, highlighting a spiked pattern, longitudinal striae, and subungual hyperkeratosis at the distal edge. Panels G and H demonstrate fungal melanonychia via dermoscopy, characterized by a multicolor pattern including black and yellow streaks, a reverse triangular pattern (base at the distal edge), and surface scaling. The collection serves to demonstrate the integration of physical examination, microscopy, histopathology, and onychoscopy in the diagnosis of fungal nail infections.

This diagnostic image shows a direct microscopic examination of a clinical specimen using a potassium hydroxide (KOH) mount. The field of view displays clear, translucent fungal elements against a light, granular background characteristic of digested host tissue. The primary features include long, slender, septate hyphae that exhibit regular cross-walls and occasional branching. Associated with these hyphal structures are chains of conidia (spores) in an acropetal arrangement, suggesting fungal proliferation. The morphology is consistent with a phaeohyphomycotic or related filamentous fungal infection, particularly Cladophialophora species in the context of a cerebral abscess. This visual aid is intended for medical education in microbiology and infectious diseases to demonstrate the rapid identification of fungal morphology in clinical exudates. The absence of bacterial structures and the presence of septate hyphae with conidial chains provide a definitive visual diagnostic path for beginning antifungal therapy before culture confirmation.

This composite image illustrates the clinical and diagnostic features of fungal keratitis. Panel A is a clinical photograph of the eye showing a significant central and peripheral corneal ulcer characterized by feathery, infiltrating margins, elevated lesions, a dry-appearing surface, and surrounding conjunctival hyperemia. Panel B presents an in vivo confocal microscopy image, revealing a dense network of highly reflective, branching filamentous structures consistent with fungal hyphae within the corneal stroma. Panel C shows a Gram-stained microscopic view of corneal scrapings, where a deep purple, septate fungal hypha is clearly visualized against a pink cellular background. Panel D displays a potassium hydroxide (KOH) wet mount of corneal scrapings under light microscopy, demonstrating translucent, slender, branching fungal hyphae. This series of images demonstrates the progression from clinical presentation to definitive microbiological diagnosis using various imaging and staining modalities, highlighting the morphological characteristics of mycotic corneal infections.

The image consists of two panels demonstrating clinical and laboratory findings associated with invasive fungal sinusitis. Panel A is a diagnostic nasal endoscopy (DNE) photograph showing the right nasal cavity. The mucosa is significantly erythematous and inflamed, featuring extensive dark-brown to black devitalized tissue (eschar) along the turbinates and lateral wall, characteristic of angio-invasive fungal necrosis. Panel B is a bright-field microscopy image of a potassium hydroxide (KOH) mount prepared from a nasal biopsy. It demonstrates fungal elements consistent with Mucorales, characterized by broad, pauciseptate (ribbon-like) hyphae and rounded sporangia/spores. These findings are pedagogically relevant for identifying rhino-orbital-cerebral mucormycosis (ROCM), particularly in immunocompromised or diabetic patients. The combination of visual necrotic tissue (black turbinate sign) and specific fungal morphology provides a comprehensive diagnostic overview of acute invasive fungal infection.

This diagnostic image shows a microscopic direct examination of a skin scrapings sample at 400x magnification. The specimen is processed using a potassium hydroxide (KOH) and Myco-Ink preparation to identify dermatophytes. The visual field demonstrates a network of septate, branching fungal hyphae stained a distinct blue by the Myco-Ink, which binds to chitin in the cell walls. The hyphae appear as elongated, filamentous structures that are intertwined and matted in some regions, typical of Trichophyton quinckeanum morphology. The KOH has cleared the surrounding keratinous epidermal debris, providing high contrast between the darkly stained fungal elements and the lighter, translucent background. This preparation is a critical clinical tool in dermatology for the rapid diagnosis of tinea infections (zoonotic dermatophytosis), allowing for the visualization of hyphal morphology, distribution, and branching patterns necessary for preliminary mycological identification.

A composite image illustrating the diagnostic mycological and histopathological features of Sporothrix globosa. Panel A (Microscopy): Direct microscopy of an exudate smear using a 10% KOH preparation (400x) reveals slender, translucent, thread-like hyphae (indicated by a red arrow) against a cleared background of squamous cells. Panel B (Pathology): A high-magnification histopathological section (1000x) with Periodic Acid-Schiff (PAS) staining demonstrates intracellular fungal spores (indicated by a red arrow) localized within a multinucleated giant cell, surrounded by a dense inflammatory infiltrate. Panel C (Microbiology): A macroscopic photograph of a fungal culture on a Sabouraud dextrose agar (SDA) slant after 9 days of incubation at 25°C. The culture shows characteristic brownish-beige, moist colonies with a wrinkled, irregular, and slightly raised texture typical of Sporothrix species. This collection of images summarizes the laboratory findings necessary for diagnosing cutaneous disseminated sporotrichosis in a clinical setting.