Case Study: Inflamed foot cyst may be fungal tumor

Summary

Fungal infections are very common in India, especially tenia pedis and other superficial fungal infections. Mycetoma is a chronic granulomatous infective disease of the skin and related tissues,[5] predominantly seen in tropical countries, and it generally presents as superadded long-standing infections over already unhealthy skin or wounds. Common presentations are long-term, non-healing, discharging sinuses and confluence of necrotic grayish-white or pigmented nodules. However, it may present as a subcutaneous cyst like the woman described here. Ruling out other differential diagnoses and treatment are also important.

Background

Mycetoma is a disease that occurs mainly in regions in a narrow region north of the equator. It can be caused either by actinomycetoma bacteria or by eumycetoma fungi (typically madurella mycetomatis.) Traces of the fungus are found in the environment, but do not cause illness in most people who come in contact with it. [4]

Case Presentation

A 32-year-old female patient, a farmer by occupation, presented with swelling of the left heel region, with a healed sinus and a solitary painful cyst measuring 2.8 cm in diameter. She gave a history of sinuses in the left foot. The working diagnosis was a plantar epidermal cyst. The patient was otherwise fit and well, with no history suggestive of immunosuppression. She was not diabetic and was not on steroids or other medications.

Investigations

1. Routine blood examination: revealed eosinophilia (860/µl)
2. Ultrasonography to assess the cyst; its contents and extension
3. X-ray: to rule out underlying bone involvement
4. Sonogram or dye-test to locate and assess the sinus
5. Routine bacterial, fungal and AFB culture

Differential Diagnosis

1. Parasitic cyst
2. Epidermal inclusion cyst
3. Tuberculosis
4. Bursa
5. Mycetoma or fungal tumor
6. Ganglion
7. Skin adnexal tumors or benign cystic lesions

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