Case 201. Myiasis (38 y-o M)
         
    A painful, cratered skin nodule on the elbow of a Japanese who stayed in Brazil    
         
   
Key words : 
Dermatobia hominis, Cordylobia anthropophaga, furuncular myiasis    
     
 
     
The maggot of fly (myia in Greek) may cause funicular myiasis, and the nodule is called "warble". Marked inflammatory reaction is seen around the intradermal cavity (HE). Myiasis by Drematobia hominis is endemic in both American continents.   Histology of the head portion of the larva (maggot) obtained from the cavity shows the gnathosoma with well-developed striated muscles and spiculated cuticle (HE).
     
 
     
Histology of the body portion of the larva (maggot) shows the cuticle, striated muscles, fat bodies, food channel and spiracles (HE).   Reference case 201A
Myiasis caused by Cordylobia anthropophaga on the back of a Japanese male who stayed in Zambia (gross findings). Funicular myiasis with central crater formation. The warble was painless. Two maggots were obtained from the lesion.
     
 
     
Reference case 201A
The second-instar maggot of Cordylobia anthropophaga obtained from the crater of the skin nodule (close-up view). The 7 mm grayish white maggot possesses 13 body segments. Black dots are seen around the head.
  case 201B
Semispecific myiasis seen in squamous cell carcinoma of the facial skin in the aged with dementia. The ulcerated 3 cm skin cancer is badly smelled, and numerous maggots are obtained from the ulcer base (gross findings).
     
 
     
Reference case 201B
A total of 54 maggots were obstained from the necrotic ulceration of cancer. In semispecific myiasis, eggs are incidentally blown to necrotic lesions of the body surface. The maggot is thus not primarily pathogenic.
  Reference case 201B
The maggot was identified as third-instar larva of Lucilia caesar, a common fly throughout Japan. The fly causing "specific myiasis" such as D. hominis and C. anthropophaga, is not distributed in Japan.
     
 
     
Reference case 201C
Accidental myiasis. The maggot of Sarcophagidae was obtained from the stool (HE). Two possibilities should be considered: Ingestion of egg-blown meat (the maggot was layed in the bowel) and blowing eggs by the fly just after defecation (the maggot was layed outside the bowel).
  Reference case 201C
Accidental myiasis. The histology of the maggot obtained from the stool is shown (HE). The spiculated cuticle, striated muscles, fat bodies, food channels and spiracles are seen.