case 6 - virtual pathology · • lymphadenitis • osteomyelitis • skin infectionsinfections –...

Case 6Case 6

F l 89• Female 89 years• 3 month history of worsening nodules on legs. On treatment for temporal arteritis has clinicaltreatment for temporal arteritis, has clinical evidence of Tinea Pedis

• Biopsy from nodule left calf• Biopsy from nodule left calf• The best diagnosis is

A Atypical Mycobacterial Infection– A. Atypical Mycobacterial Infection– B. Deep Fungal Infection– C Large Vessel Vasculitis– C. Large Vessel Vasculitis– D. Subcutaneous Sweet’s Syndrome

Case 6Case 6

F l 89• Female 89 years• 3 month history of worsening nodules on legs. On treatment for temporal arteritis has clinicaltreatment for temporal arteritis, has clinical evidence of Tinea Pedis

• Biopsy from nodule left calf• Biopsy from nodule left calf• The best diagnosis is

A Atypical Mycobacterial Infection– A. Atypical Mycobacterial Infection– B. Deep Fungal Infection– C Large Vessel Vasculitis– C. Large Vessel Vasculitis– D. Subcutaneous Sweet’s Syndrome

Case 6Case 6

F l 89• Female 89 years• 3 month history of worsening nodules on legs. On treatment for temporal arteritis has clinicaltreatment for temporal arteritis, has clinical evidence of Tinea Pedis

• Biopsy from nodule left calf• Biopsy from nodule left calf• The best diagnosis is

A Atypical Mycobacterial Infection– A. Atypical Mycobacterial Infection– B. Deep Fungal Infection– C Large Vessel Vasculitis– C. Large Vessel Vasculitis– D. Subcutaneous Sweet’s Syndrome

Case 6Case 6

F l 89• Female 89 years• 3 month history of worsening nodules on legs. On treatment for temporal arteritis has clinicaltreatment for temporal arteritis, has clinical evidence of Tinea Pedis

• Biopsy from nodule left calf• Biopsy from nodule left calf• The best diagnosis is

A Atypical Mycobacterial Infection– A. Atypical Mycobacterial Infection– B. Deep Fungal Infection– C Large Vessel Vasculitis– C. Large Vessel Vasculitis– D. Subcutaneous Sweet’s Syndrome

Mycobacterium Fortuitumcomplex: m.furtuitum, h l bm.chelonae, m. abscessus

• Can be distinguished on basis of DNA, g ,but similar clinical presentation

M Ch l i l t d b F i d i• M. Chelonae isolated by Friedman in 1903 (2 subspecies: chelonae and abscessus, but abscessus later reclassified as separate species)p p )

Epidemiology and pathogenesisp gy p g

S h f d i il d d i l• Saprophytes: found in water, soil, dust and animals• Cutaneous infections uncommon• Immunocompromised pnts more susceptible to severe diseasell h d• Following trauma, surgery, or other procedures 

(liposuction, mesotherapy), placement of implants (breast) tattooing post injection abscess (acupuncture(breast), tattooing, post‐injection abscess (acupuncture / botox), footbaths in nail salons

• Dissemination from an endogenous source is lessDissemination from an endogenous source is less frequent

Clinical featuresClinical features

• N it t i• Non‐cavitatory pneumonia• Keratitis• Endocarditis• Lymphadenitis• Osteomyelitis• Skin infections• Skin infections

– Cellulitis– Abscesses

P l l– Papulo‐pustules– Sinuses– Ulcers with necrosis– Multiple erythematous nodules frequently on distal limbs or in 

sporotrichoid pattern

pathologypathology

• Neutrophilic microabscesses and granulomaformation with FB type giant cells +/‐ necrosisyp g

• NOTE: fast‐growers – may only see neutrophilic abscess with necrosis andneutrophilic abscess with necrosis and karyorrhexis, with little or no granulomaf f bformation. Pseudocyst formation may be noted

• Wade‐Fite more consistent than Z‐N stain

DiagnosisDiagnosis

• Culture of biopsy material rather than aspiration of pus preferredp p p

• Organisms grow on routine bacterial culture media e g 5% sheep blood agar or chocolatemedia e.g. 5% sheep blood agar or chocolate agar within 7 days

• PCR detection of 16S‐23S rRNA gene internal transcribed spacer sequences can betranscribed spacer sequences can be performed

treatmenttreatment

• Resistant to anti‐TB therapy

• All M. Chelonae and 80% M. FortuitumAll M. Chelonae and 80% M. Fortuitumsensitive to Oral Clarithromycin

E i i d b id b• Excision or debridement may be necessary

Case 6Case 6

• Cultures: Mycobacterium Chelonei

• Treated with Oral Clarithromycin 500mg bd forTreated with Oral Clarithromycin 500mg bd for 3 months with complete resolution of nodules