modura foot

[DrGilani]

SONOGRAPHIC PRESENTATION AND DIFFERENTIAL DIAGNOSIS OF MYECTOMA (Modura foot).

Qureshi Mohamed Ali 1, Syed Amir Gilani 2, Elreyah Mustafa 3
1; Principal National College, Khartoum Sudan.
2; Associate Professor, Alzaeim Alazhari University, Khartoum Sudan.
3; Consultant Radiologist; Faisal Specialist Hospital, Khartoum Sudan.

Abstract;
A total 50 clinically diagnosed cases of mycetoma were taken for this multicentre study at Faculty of Radiological Sciences, Alzaeim Alazhari University, Khartoum Sudan (2) and at Faisal Specialists Hospital Khartoum, Sudan (3).All patients were scanned by at least two of the researchers and their sonographic presentation was recorded for establishing a criteria for sonographic appearance of both main types of mycetoma.

INTRODUCTION
Mycetoma is a chronic, specific, granulomatous, progressive inflammatory disease; it usually involves the subcutaneous tissue after a traumatic inoculation of the causative organism.
Mycetoma may be caused by true fungi or by higher bacteria.
Tumefaction and formation of sinus tracts characterize mycetoma.
The sinuses usually discharge purulent and seropurulent exudate containing grains. It may spread to involve the skin and the deep structures resulting in destruction, deformity and loss of function, very occasionally it could be fatal.
Types; The two forms of mycetoma are bacterial mycetoma and fungal mycetoma: 1) bacterial mycetoma is known as actinomycetoma
2) Fungal form is called eumycetoma.
Even at the level of electron microscopy the two forms of mycetoma are difficult to distinguish from one another.
Epidemiology; The African continent seems to have the highest prevalence. It prevails in what is known as the mycetoma belt stretching between the latitudes of 15 souths and 30 norths. The belt includes Sudan, Somalia, Senegal, India, Yemen, Mexico, Venezuela, Colombia, Argentina and others. Areas where mycetoma prevails are zones with a short rainy season with a relative humidity.
The organisms are usually present in the soil in the form of grains. The infecting agent is implanted into the host tissue through a breach in the skin produced by trauma caused by sharp objects such as thorn pricks, stone or splinters.
The disease is endemic in the tropics and subtropics and is named after the region of India where it was first described in 1842.
Although currently uncommon in temperate regions, it does occur in the southern USA, and cases are found in the homeless, and AIDS sufferers.
Pathogenisis; The disease is usually acquired while performing agricultural work, and it generally afflicts men between 20 and 40 years old.
The disease is acquired by contacting grains of bacterial or fungal spores that have been discharged onto the soil.
Infection usually involves an open area or break in the skin. Pseudoallescheria boydii is one of many fungi spp. that causes the fungal form of madura foot.
Infections normally start in the foot or hand and travel up the leg or arm.
Diagnosis; The disease is characterized by a yogurt-like discharge upon maturation of the infection.
Hematogenous or lymphatic spread is uncommon.
Diagnosis of mycetoma is usually accomplished by radiology, ultrasound or by fine needle aspiration of the fluid within an afflicted area of the body.
CAUSATIVE SPECIES
Species of bacteria that cause Mycetoma include:
Nocardia veterana.
Nocardia transvalensis.
Actinomadura madurae.
Actinomadura pelletieri.
Streptomyces somaliensis.
Species of fungus that cause Mycetoma include:
Exophiala jeanselmei.
Madurella grisea.
Madurella mycetomatis.
Leptosphaeria senegalensis.
Scedosporium apiospermum.
Pseudallescheria boydii.

Clinical presentation of disease;
Presentation Following the initial injury, the disease typically follows a slow chronic course over many years with painless swelling and intermittent discharge of pus.
There may be a deep itching sensation.
Pain may occur due to secondary bacterial infection or bone invasion.
After some years, massive swelling of the area occurs, with in duration, skin rupture, and sinus tract formation. As the infection spreads, old sinuses close and new ones open.
The exudates are typically granular.
DIFFERENTIAL DIAGNOSIS
Differential diagnosis The main differential diagnoses are chronic bacterial osteomyelitis, tuberculosis, or the early phase of Buruli ulcer.
Other deep fungal infections such as blastomycosis or coccidomycosis.
Leishmaniasis, yaws and syphilis should be considered.
Investigations Microscopy and culture of exudates, and skin biopsy for pathology are necessary to identify the causative organism.
Serology can be helpful with diagnosis or follow-up care during medical treatment.
DNA sequencing has been used for identification in difficult cases.
Plain x-rays are used to assess for evidence of bone involvement.
CT scan may be more sensitive in the early stages.
MRI scans can provide a better assessment of the degree of bone and soft tissue involvement; and may be useful in evaluating the differential diagnosis of the swelling.
Material;
These 50 patients included 18 female and 32 males age ranging from 20 to 70 years. 16(32%) had pustules at back and lateral side of abdomen whereas 30 (60%) had involvements of limbs (upper or lower limbs) and 4(8%) had involvement of extremities as well as back.
All that patients were scanned on GE Logic-9 and Shamadzo’s Color Doppler using convex as well as linear high frequency transducers with color and power Doppler. Images and real time video clips were saved.


Results;
These 50 patients were sent for cytological examination after having ultrasound guided aspiration. The lab tests confirmed the diagnosis of 46 (92%) cases as mycetoma. Our accuracy for diagnosis of bacterial type was 94% and for fungal type 90%.

Sonographic presentation
1) Jelly like hypo to anechoic mass with rounded or oval hyperechoic granular structures which are moving /floating at real time scanning.
2) In fungal type fluid contents are more as compare to other type, in some types conditions we can get halo around the hyperechoic sticks (granules) in fungal type.
3) In bacterial type in most of the cases a capsule like outlines is seen around the lesion whereas in all cases diagnosed a fungal we didn’t find any capsule around it.
4) On color Doppler signs of hyperemia are present. More flow is seen in bacterial type as compare to fungal type.(Gilani.et.al)

COMPLICATIONS
The disease causes disfigurement but is rarely fatal.
In advanced cases, deformities or ankylosis may occur.
Chronic neglected infection may necessitate amputation.
Immunocompromised patients may can develop invasive infection.
Lymphatic obstruction and fibrosis may cause lymphoedema.
Complications may result from toxicity due to prolonged antimicrobial or antifungal therapy.
Prognosis Actinomycetoma can be cured with the appropriate antibiotic therapy but eumycetoma has a high rate of recurrence and can require amputation.
Discussion;
This is the first ever sonographic study for diagnosis and for differential diagnosis of mycetoma which is a very fatal disease and very common in Africa. The accuracy of our study is suggestive of prime role of ultrasound in diagnosis of this disease with usually results in amputations or deaths.
As the results indicate the accuracy of ultrasound 92% cases as mycetoma. accuracy for diagnosis of bacterial type was 94% and for fungal type 90%.

Conclusion; Ultrasound is very accurate in diagnosis of mycetoma and even in differential diagnosis of its types.
Recommendations;
Ultrasound with color Doppler and high frequency transducer is very effective and accurate; it must be used as first diagnostic tool.

REFERENCES
1) Loulergue P, Hot A, Dannaoui E, et al (December 2006). "Successful treatment of black-grain mycetoma with voriconazole". Am. J. Trop. Med. Hyg. 75 (6): 1106–7. PMID 17172376.
2) Kano R, Hattori Y, Murakami N, et al (2002). "The first isolation of Nocardia veterana from a human mycetoma". Microbiol. Immunol. 46 (6): 409–12. PMID 12153118.
3) Mirza SH, Campbell C (January 1994). "Mycetoma caused by Nocardia transvalensis". J. Clin. Pathol. 47 (1): 85–6. PMID 8132817. PMC:501765.
4) Severo LC, Oliveira FM, Vettorato G, Londero AT (March 1999).
5) "Mycetoma caused by Exophiala jeanselmei. Report of a case successfully treated with itraconazole and review of the literature". Rev Iberoam Micol 16 (1): 57–9. PMID 18473595.


for all my friends with compliments
DR GILANI

[dr.basil shamma]

a great work ...in our country we just hear about this disease and see it in medical images , it is wonderful study hope to see more researches of the AAIMS
I hope to see ultrasound images of some cases in this study.