Case Number : Case 1595 - 05 August Posted By: Guest

Cutaneous  infestation with a Nematode: Onchocercoma?

Agree with onchocercoma

Agree. Nice!

This is not onchocerciasis.  Try again.

Dirofilariasis http://www.ncbi.nlm.nih.gov/pubmed/16643162

Here there is another good paper http://www.sciencedirect.com/science/article/pii/S0732889398001643

Dirofilariasis is a good differential.

Here an other paper 

Human subcutaneous dirofilariasis  

V Srinivasamurthy¹,  M Sudha Rao¹,  MU Thejaswini¹,  Yoganand^2
1 Department of Pathology, ESIC Medical College and PGIMSR, Rajajinagar, Bangalore, India
² Department of ENT, ESIC Medical College and PGIMSR, Rajajinagar, Bangalore, India

Well done Raul.  Yes this is dirofilariasis.  It is a microfilarial nematode transmitted by mosquitos to cat's dogs and other vertebrates.  Humans are usually a dead-end host with only immature worms (note the microfilaria are not well formed) but human subcutaneous dirofilariasis with blood filariasis has been reported exceedingly rarely.  Clues to diagnosis are the longitudinal cuticular ridges (seen as transverse sections c.f. Onchoercisis that has transverse striations) and thicker muscle (c.f onchocerciasis, thin muscle).  There is a nice onchocercoma in dermpathpro Case 1097 for comparison.  In this case likely species in dirofilaria (nochtiella) repens that is endemic in Sri Lanka, parts of Italy, eastern Europe & Russia), presents with subcutaneous nodules and adult worms infect the eyes (cf oncherciasis with microfilaria in the conjunctiva / eyes).  Dirofilaria immitis can present with nodules in the lungs and heart of dogs, cats and humans.  Many thanks to Manu Singh for this case which came from Sri Lanka.