Mycetoma

What sample is needed for mycetoma?

1. Get a sample from the lesion.
2. Can take a biopsy of the lesion.

How will you define Mycetoma?

1. Mycetoma may be:
   1. Eumycetoma is due to fungi.
   2. Actinomycetoma is due to filamentous bacteria.
2. Mycetoma due to fungal growth or Maduro mycosis of the foot.
3. The term mycetoma refers to a severe, deeply chronic, locally progressive, destructive, suppurative, and granulomatous disease.
4. It begins in the subcutaneous tissue, usually of the hand and foot.
5. This involves subcutaneous tissue, fascia, and bone.
6. It is characterized by tumefaction, draining sinuses, and granules.

How will you summarize mycetoma?

• Swelling (nodule) + Granules in the discharge + multiple draining sinuses.

How will you discuss the pathology of Mycetoma?

1. Two types of microorganisms cause Mycetoma:

Bacterial causes are:

1. These are aerobic actinomycetes that cause mycetoma, which is called actinomycetoma in more than 50% of cases.
2. The organisms in this group are:
   1. Nocardia Brasiliense’s.
   2. Actinomadura pelletieri.
   3. Actinomadura madurae.
   4. Streptomyces somaliensis.
3. Actinomyces are:
   1. Actinomyces israelli. It produces actinomycosis.
   2. This chronic internal abscess formation will develop a sinus tract to the skin.
   3. Purulent exudate contains yellow granules called sulfur granules.
   4. These sulfur granules are masses of actinomycetes.
   5. Actinomyces Bovis.

Fungal causes are:

1. Fungal infection causes the other 50% of cases.
2. This is called Eumycetoma, also known as maduromycosis, and is caused by a true fungus.
3. At least 23 types of filamentous fungi cause Mycetoma. An important one is:
   1. Pseudallescheria boydii (There are yellow granules).
   2. Madurella mycetomatis (There are big black granules).
   3. Medurella grisea.

What are the types of mycetoma?

1. Eumycetoma is due to fungal diseases.
2. Actinomycetoma is due to bacterial causes.

What would be the presentation of mycetoma?

1. Mostly, the feet are involved, and less commonly, hands and other sites are involved.
2. This chronic, suppurative, granulomatous inflammation can involve subcutaneous tissue, fascia, and bone.
3. The etiological agents enter the body through the foot from the soil, possibly due to trauma.
4. When the foot is involved, swelling and discoloration occur, and numerous draining sinuses form.
   1. This disease is characterized by tumor formation and abscess drainage.
5. There is the presence of granules or grains in the pus.
   1. Depending on the causative agent, these granules vary in color: white, black, yellow, and brown.

6. Mycotic mycetoma is more common in men than in women.
7. Mycotic mycetoma is usually caused by foot injury.

How will you discuss the pathogenesis of mycetoma due to fungi?

1. When fungi are implanted in the subcutaneous tissue following trauma.
2. A destructive granulomatous lesion drains through multiple sites.
3. It spreads locally but does not disseminate.
4. The most common site is the foot, and this infection is called the Medura foot.
5. Causative agent:
6. Important fungi are filamentous, including:
   1. Medurella mycetomatis.
   2. Medurella grisea.
   3. Phialophora verrucosa.
7. Pathogenesis of fungal Myecetoma:
   1. First, fungi are implanted into the tissue after trauma, which may be caused by a splinter.
   2. It produces destructive granulomatous inflammation.
   3. Later, the lesion drains through multiple sinus tracts.
   4. There is local spread but no widespread dissemination.
   5. This is common in barefoot people.

How will you differentiate the color of the granules?

1. Black color is due to Medurella mycetomatis, Medurella grisea, and Falciformispora.
2. White and pale ones are due to Acremonium, Fusarium, Neotestudina, and Scedosporium apiospermum.
3. Yellow and pale ones are due to other fungi and Aspergillus.

How will you diagnose mycetoma?

1. Collect the granules from the lesion.
   1. Then, wash the granules with the saline, crush it, and spread it on the slide.
2. Also, the culture of the material should be taken into account. Culture is done on the Sabouraud’s medium for fungus.
3. Prepared slides are stained with Gram’s stain :
   1. The filaments are less than or equal to 1.0 micrometers in diameter, a diagnostic of aerobic actinomycetes called actinomycetoma.
   2. If the filaments are 2 to 5 micrometers and hyphal in shape, the diagnosis of fungal infection is called eumycetoma.
4. These granules can also be seen in the KOH 10% solution.

How will you treat mycetoma?

1. The prognosis of Eumycetoma is poor.
   1. These patients undergo surgical debridement and oral Itraconazole 200 mg twice a day for a prolonged period of time, and their response is only 70%.
   2. These patients may be given combination therapy.
2. Mostly, these are treated by surgery.
3. Chemotherapy is not effective and is given for a prolonged time.
4. Treatment surgical and chemotherapy are ineffective when the mycetoma is due to fungi.

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