Case Report: Myiasis as a rare complication of invasive ductal carcinoma

Introduction

Breast carcinoma is the second-leading cause of cancer-related mortality in women. Invasive ductal carcinoma is most common histological subtype of breast carcinoma¹. Myiasis is the dipterous larvae infestation of human or animal tissues. It is typically associated with inadequate personal hygiene due to lack of awareness among individuals in tropical and subtropical countries. Dipterous larvae in the feeding life cycle of may be found in living or dead tissues^2–5. Many treatment options are available for invasive ductal carcinoma found with gangrenous tissues, with radiotherapy considered highly commendable in order to reduce disease recurrence^6,7.

Case report

A 50-year-old female presented to the surgical department at Ziauddin Hospital Karachi with complaints of pain, redness, blackening, and a foul smelling and discharging wound in the left breast. She had a history of invasive ductal carcinoma which was diagnosed 2.5 years previously but could not get treatment for financial reasons. (Figure 1). On examination, the patient looked weak and lethargic. She had a fever of 101°F (38.3°C) The majority of the breast was hard in consistency with a purulent sanguineous discharging ulcer, which was foul smelling due to superimposed bacterial infection. The surrounding skin was gangrenous and numerous grayish maggots were seen crawling around.

Figure 1. Histological resection of invasive ductal carcinoma.

The wound was debrided thoroughly with povidone-iodine in the emergency room and about 52 maggots were removed carefully, preserved and sent for entomological review which were identified as Chrysomya bezziana. The maggots were 15 to 20 mm long, whitish or greyish in color without body process. There is an enlargement of anterior spiracle and darkened portion of trunks, posterior spiracle extended three or four abdominal segments (Figure 2 and Figure 3). The patient was given wide-spectrum antibiotic amoxicillin 1 g twice a day for 7 days and Ivermectin 6 g twice a day for 1 day according to protocol⁸. Total mastectomy was performed in the oncology department at Ziauddin Hospital as part of palliative treatment due to the gangrene and myiasis. She was also started on radiotherapy and chemotherapy for ductal carcinoma; the chemotherapeutic regimen included capecitabine 1200 mg/m² twice a day for 21 days with repeat cycles after every 21 days for 6 weeks. Total radiation dose was 5000 cGy delivered in 25 fractions 5 days a week for 6 weeks. Two months after ceasing her treatment with ivermectin and amoxicillin, breast tissue was healed and surrounded by scarring.

Figure 2. Photograph showing a well demarcated ulcer with myiasis.

Figure 3. Photograph showing a resected ulcer with numerous Chrysomya bezziana larvae.

Discussion

Cutaneous myiasis is a rare entity. It is an infestation of human skin with maggots of flies which feed on host tissues. There are two classifications of myiasis, anatomical and ecological. The first description of myiasis was given by Hope in 1840. Since then many cases of myiasis affecting different human organs have been described^2,3,6,7. Francesconi⁴ used an anatomical classification of myiasis, in which it is grouped into sanguinivorous or bloodsucking, cavitary, wound, cutaneous, furuncular and migratory myiasis.

Flies lay eggs which hatch in a humid and warm environment, and larvae can get access directly to skin from wet clothes, buds or insects. Cutaneous myiasis is very uncommon; the majority of cases are caused by human botfly (Dermatobia hominis)^5,8,9. Cutaneous myiasis is presented as a slow developing ulcer or boils. Some of the physical presentations of mastitis are similar to those of carcinoma of the breast¹⁰. It is important to note that an affected breast with myiasis, which appears like fungating mass with an ulcer, can be sometimes misdiagnosed and is confused with tuberculosis, mycosis, actinomycosis, furunculosis, chronic breast abscess, fungating malignancies, periductal mastitis, inflammatory carcinoma of the breast and cellulitis^10,11. Therefore, it is very important to keep this rare but possible disease in the differentials when diagnosing the condition.

Sample larvae should be promptly preserved after removal in order to maintain their identity, because subsequent treatment is based on the type of the organism identified. Various techniques are available to remove larvae without affecting their shape and structure^12,13. Risk factors should also be kept in mind, such as living in endemic areas, the characteristic intense itching of the affected breast, offending maggots (seen via a hand magnifying glass) are invaluable aids to the diagnosis and treatment. Poor personal hygiene is an important cause of myiasis;. it can be prevented by proper sanitation, good personal hygiene, spraying insecticides for flies and removal of garbage from nearby streets. Clothes should be worn after washing, drying in sunlight and ironing in order to prevent myiasis¹⁴.

After the treatment of myiasis, any remaining ulcer should be biopsied in order to rule out any malignancy, as in our case, cutaneous (breast) myiasis simultaneously occurred with invasive ductal carcinoma (Figure 2) and after surgical removal (Figure 3) was confirmed with a biopsy (Figure 1). Invasive ductal carcinoma is the most common type of breast cancer, making up nearly 70–80% of all breast cancer cases. Invasive or infiltrative ductal carcinoma is the presence of abnormal cancer cells in the lactiferous ducts that have spread into other parts of the breast tissue. It can also metastasize to other parts of the body. Histological examination of breast cancer is mandatory to confirm the diagnosis and to establish different pathological prognostic factors^15,16.

Conclusion

Cutaneous myiasis with breast cancer is a rare but possible entity and we should include it in our differentials which is important to avoid any further delay in diagnosis and adequate treatment in the future.

Data availability

All data underlying the results are available as part of the article and no additional source data are required.

Consent

Written informed consent for publication of clinical details and clinical images was obtained from the patient.