A case of dermal non-necrotising granulomatous disease

Introduction: 52 year old male presented with multiple subcutaneous lumps on left forearm present for several months. Previously employed hanging dead kangaroos and pigs and thought kangaroo claws scratched left arm. Shortly thereafter developed erythematous, pruiritic rash on forearm which developed into tender lumps. Otherwise well with no breathing difficulties, fevers or malaise. Previously from Finland. No medical conditions, medications or allergies. No intravenous drug use. Had tattoo of left arm performed in New Zealand two years ago. Multiple other tattoos.
Examination: Approximately seven indurated, discrete subcutaneous lumps up to elbow. No overlying erythema. New lumps appearing over middle distal finger outside tattoo. Able to move fingers and elbow. Chest clear, no fevers or lymphadenopathy.
Pathology: Biopsy of left forearm showed fibro-adipose tissue with florid non-necrotising granulomatous inflammation comprising naked epithelioid granulomas with multi-nucleate giant cells surrounded by chronic inflammatory cell infiltrate. No microorganisms seen on special stains (PAS, Wade-Fite and Ziehl-Neelsen). No evidence of malignancy.
Differential Diagnoses: Sarcoidosis, infections including mycobacterial or deep fungal (nocardia, actinomyces), Beryllium disease, drug or tattoo reaction.
Investigations: No growth on tissue culture. 16SRNA and M ulcerans PCR negative. Chest X-ray and serum ACE negative. Q fever and Brucella serology non-reactive as was Leishmaniasis PCR. HIV, syphilis, Hepatitis B and C serology also negative.
Discussion: Despite excision of and further testing of lesions no diagnosis found to date. This case prompts consideration of the causes of non-necrotising granulomatous inflammation and how they can present, including infectious and atypical presentations of non-infectious causes.

Dr. Kylie Beem

Greenslopes Private Hospital

Dr Kylie Beem is a senior house officer at Greenslopes Private Hospital in Brisbane who is seeking to specialize in dermatology. Kylie has completed several dermatology terms at the Princess Alexandra Hospital in Brisbane as well as volunteering her time at the Mater Hospital dermatology outpatient clinics. She has also completed elective terms with private dermatology practices and spent time volunteering as a medical student in the Solomon Islands dealing with a wide variety of tropical skin diseases. She is passionate about dermatology and has also contributed to running the Australasian College of Dermatologists' Fellowship clinical examinations held in Brisbane in 2016. She is a member of the Brisbane Hospitals Dermatology Group.