Visual Atlas / Mycology

Scedosporium / Lomentospora: Flask Cells and Annelloconidia

Original bench-card visual for recognizing Scedosporium and Lomentospora: flask-shaped conidiogenous cells producing single annelloconidia at the tip on hyaline septate hyphae.

Next step

Reinforce this visual pattern with mixed clinical microbiology questions.

Practice related review questions
Bench card visual

Scedosporium / Lomentospora: flask cells with single annelloconidia

Read first

Scedosporium and Lomentospora are opportunistic hyaline molds. The anchor is a flask-shaped conidiogenous cell bearing single oval annelloconidia at the tip, set on septate hyphae.

Conidiogenous cellFlask-shaped, single tip conidium

Flask-shaped or annellidic cells produce a single oval conidium at the tip. Conidia often gather as small clusters at the apex.

HyphaeHyaline septate mold

Septate hyphae place this in the hyaline mold group. Conidiogenous cell shape, not hyphae alone, points toward Scedosporium or Lomentospora.

What to look for

Scedosporium / Lomentospora anchors

Visual clueMeaningStudent shorthand
Flask-shaped conidiogenous cellScedosporium patternSwollen base tapering to a neck is the main clue
Single oval conidium at the tipAnnelloconidium clueConidia form one at a time, often clustering at the apex
Hyaline septate hyphaeOpportunistic mold contextOverlaps with Aspergillus and Fusarium on hyphae alone
Sterile site or near-drowning historyClinical contextSignificance depends on source and host; interpret per SOP
Interpretation table

Scedosporium / Lomentospora interpretation guide

PatternWhat to call itHow to think about it
Flask cells with single tip conidiaScedosporium-compatible morphologyConfirm by validated mold ID workflow
Compact conidial head on a vesicleAspergillus patternDifferent reproductive structure
Curved multicelled macroconidiaFusarium patternDifferent conidial shape
Key takeaways
  • Scedosporium and Lomentospora are conidiogenous-cell-shape cards.
  • Flask cells with single tip conidia separate them from other hyaline molds.
  • Lomentospora resistance makes correct identification and SOP escalation important.
Remember

Scedosporium / Lomentospora = flask cells with single oval conidia on septate hyphae.