Zygomycosis

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Zygomycosis

• Epidemiology
• Typically involves the rhino-facial-cranial area,
  lungs, gastrointestinal tract, skin, or less
  commonly other organ systems.
• Often associated with diabetes, starvation,
  severe burns, IV drug abuse, and other diseases
  such as leukemia and lymphoma, immunosuppressive
  therapy, or the use of cytotoxins and
  corticosteroids and other major trauma.
• Has a predilection for invading arterial vessels
  causing embolization (arterial occlusion) and
  subsequent necrosis of surrounding tissue. A
  rapid diagnosis is extremely important if
  management and therapy are to be successful.

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Clinical manifestations

• Rhinocerebral
• Most frequent clinical zygomycete presentation
• Infections usually begin in the paranasal
  sinuses following the inhalation of
  sporangiospores and may involve the orbit,
  palate, face, nose or brain
• Begins with runny nose, headache and orbital
  pain
• Can cause rapidly invasive disease characterized
  by edema of the eyelids
• Commonly predisposed by diabetes or ketoacidosis
• Rapidly fatal once it becomes cerebral

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Rhinocerebral zygomycosis
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Clinical manifestations

• Pulmonary
• Very similar to invasive bronchopulmonary
  aspergillosis - results in pulmonary infarction
  necrosis
• Patients with hematological malignancies
  (lymphoma, leukemia) are particularly at high
  risk
• Cutaneous and subcutaneous
• Local traumatic implantation of fungal elements
  through the skin, especially in patients with
  extensive burns, diabetes or steroid induced
  hyperglycemia and trauma. Lesions vary
  considerably in morphology but include plaques,
  pustules, ulcerations, deep abscesses and ragged
  necrotic patches.

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Cutaneous and subcutaneous
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Zygomycosis

• Clinical manifestations
• Disseminated
• May involve virtually any organ
• Can spread from lungs, sinus, or rarely form the
  gastrointestinal tract
• Most commonly seen in people who are
  immunosuppressed, IV drug users, or hematological
  malignancies

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Zygomycosis

• Laboratory Identification
• Microscopically zygomycetes appear in tissue as
  ribbon-like broad thin-walled non-septate or
  sparsely septate hyphae with focal bulbous
  dilations and irregular branching
• On occasion sporangia containing sporangiospores
  can be seen along with nonseptate hyphae

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Zygomycosis
Histopathology Stained Tissue
Hematoxalin and Eosin
Methenamine Silver
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Zygomycosis

• Laboratory Identification
• Zygomycetes are the fastest growing moulds
• They can completely fill a Petri culture dish
  within two to three days under optimum growth
  conditions (a clue used for identification)
• Their hyphae are hyaline but their spores are
  usually gray to black sometimes giving the colony
  an overall gray to black appearance like dirty
  snow