approach to mycetoma.pptx

A complete approach for diagnosis and treatment of a mycetoma case

1. Approach to a case of mycetoma Presenter : Dr Lakshmi Prasad, DVL PG Y II Moderator : Dr Roshni Menon, Prof and HOD, DVL

2. Patient Characteristics 20 to 40 years of age Males > females Low socio-economic status Manual workers

3. Clinical features Based on the triad Large painless tumor-like swellings, nodules ; Draining sinuses; Discharge containing grains.

4. Nodules Foot is most common, trunk and upper extremities Discharge : serosanguinous to frankly purulent Pain : bony invasion and secondary bacterial infection

5. Grains Vary in shape, size, texture and color Actinomycotic grains : Soft and brittle, off-white to pinkish Eumycotic : Firm, either black or pale

6. M.mycetomatis Black Large (>5mm), Hard Trematosphaeria grisea Falciformispora seneglanesis tompkinsii Medicopsis romeroi Exophiala jeanselmei 1-2 mm Scedosporium boydii Acremonium spp. Fusarium spp. Pale 1 mm Actinomadura madurae Large (1-5 mm), Soft Nocardia spp. Small (<0.5mm), Soft A.Pelletierii Red Smaller (0.2 – 0.5 mm), hard Streptomyces somaliensis Yellow Large round (0.5 – 2 mm), hard

7. Laboratory diagnosis

8. Direct microscopy FNAC Biopsy HPE Culture Molecular methods Serology Imaging

9. Direct microscopy Discharge is examined for grains Overnight Saline dressing if grains not observed Color, size and consistency are noted KOH and Gram stain is done by crushing the grains Calcofluor white can also be used

10. Nocardia spp.: Partially acid fast filamentous bacteria. KOH wet mount direct microscopic examination of M. mycetomatis grains showing its hyphal structure. 

11. HPE Epidermis : Normal/Hyperplastic/ulcerated Dermis : epithelioid cell granulomas with neutrophilic microabscess , with grains in center. Stains used : Gram, ZN, PAS, GMS and Gridley Eumycetoma : H&E : Large, dark brown/black/eosinophilic, with pale centres PAS and GMS : Conidia or Chlamydospores on periphery and hyphae in center. Actinomycetoma : Large, irregular with darker basophilic periphery and pale center.

12. Culture Specimen is washed several times with NS and inoculated Medium used : Modified Sabouraud dextrose agar supplemented with 0.5 % yeast Brain-heart infusion agar Lowenstein Jensen agar Eumycetoma require antibiotics contained media Penicillin G, Streptomycin or chloramphenicol Incubated for 4 – 6 weeks, at 25 and 37 degree Celsius.

13. FNAC Syringe under negative pressure in 3 different directions with short stabs/corkscrew motion is inserted and aspirated. Used in early detection and epidemiological studies. Serology Serum 1-3 beta-D-glucan was positive with Eumycetoma

14. Molecular methods MALDI-TOF MS : Matrix assisted Laser Desorption Ionization Time OF Flight Mass Spectrometry Sequencing of the gene region “internal transcribed spacer” of rDNA Direct tissue identification of the organism : pan fungal PCR assay directly on the sequencing regions, ITS1 and 2 Mold identification : Multilocus DNA sequence analysis of Large subunit (LSU) Small subunit 18S nrDNA (SSU) Β tubulin (TUB) Chitin synthase 1 (CHS-1)

15. Imaging Involvement of joints and bones X ray findings : soft tissue swelling, bone sclerosis, bone cavities, periosteal reaction, osteoporosis MRI and USG : ”Dot in circle sign”

16. USG : Eumycetoma : numerous, hyper-reflective echoes and there are single or multiple thick-walled cavities with no acoustic enhancement Actinomycetoma : echoes are closely aggregated and commonly seen at the bottom of the cavities.

17. Differential diagnosis

18. Early soft tissue swellings Phaeomycotic cysts : By HPE, Never forms tissue granules Composed of scattered individual polymorphous fungal elements Unorganised Often intracellular

19. Benign tumors-like fibromas and lipomas : Early lesions, By HPE Antibioma : antibiotic induced swelling, chronic sterile, tough fibrous abscess, mostly single, treated by excision.

20. Malignant tumors-like sarcomas : Mycetoma mimicking Synovial carcinoma

21. Lesions with discharging sinuses Mycetoma (Subcutaneous) Exogenous (traumatic inoculum) Filamentous fungi or aerobic actinomycetes Actinomycosis (Cervicofacial, pulmonary, abdominal, pelvic) Endogenous (microbiota of the digestive and genital tract) Anaerobic filamentous bacteria Botryomycosis (Subcutaneous and visceral) Endogenous (microbiota of the skin and digestive tract) Gram-positive cocci & Gram- negative bacilli

22. Bone involvement Chronic bacterial osteomyelitis : WBC : Marked leucocytosis as high as 20,000 or more. The blood culture demonstrates the presence of bacteraemia (taken during temp spike). Radiology: Lytic focus of bone destruction surrounded by zone of sclerotic bone.

23. Tuberculous osteomyelitis : Adolescents, Blood borne Extension from adjacent sites-ribs Common sites- Spine- thoracic and lumbar, Knees, Hips Pott spine- erosion of the intervertebral discs and involvement of multiple vertebrae, cold abscess-psoas abscess . HPE : Tubercular granuloma.

24. Gummatous syphilis : Relatively benign. Usually develop 1-10 years after infection and may involve any part. single or multiple. Start as a superficial nodule or as a deeper lesion that breaks down to form punched-out ulcers. Destructive but rapidly responds to treatment, heals with scar.

25. Treatment

26. Actinomycetoma Nocardia spp. : Cotrimoxazole or in combination with dapsone, minocycline, or a combination of amikacin and imipenem. Actinomadura spp. and Streptomyces spp. : co-trimoxazole with amikacin or dapsone or penicillin or streptomycin. Welsh regimen : Cycles of amikacin 15 mg/kg IV along with cotrimoxazole for 21 days with 15 days intervals when only cotrimoxazole is given (dose of oral trimethoprim sulfamethoxazole 35 mg/kg/ day). 3 to 4 times, then cotrimoxazole as maintenance therapy

27. Modified welsh regimen : To the Welsh regime, rifampicin 10 mg/kg/day is added Two-step regimen : Intensive phase with penicillin, gentamycin and cotrimoxazole for 5–7 weeks Amoxicillin and cotrimoxazole until 2–5 months after clinical cure Modified two-step regimen : Intensive phase with gentamycin 80 mg IV twice daily and cotrimoxazole 320/1600 mg orally twice daily for 4 weeks maintenance phase of cotrimoxazole (same dosage) and doxycycline 100 mg twice daily and to be continued for 6 months after clinical cure.

28. Eumycetoma often treated with a combination of antifungal therapy and surgery Itraconazole 200–400 mg/day is the treatment of choice. Other : Terbinafine 250–500 mg/day, Voriconazole 400 mg/day, Posaconazole 200–800 mg/day.

29. Complications Disfigurement but is rarely fatal. Local abscess formation, Cellulitis, and Bacterial osteomyelitis. In advanced cases, deformities or ankylosis may occur.

30. Thank you