Suppurative inflammation with microabscess and pseudocyst formation is a characteristic histologic manifestation of cutaneous infections with rapid-growing Mycobacterium species.
ABSTRACT Mycobacterial infections of the skin classically cause a granulomatous tissue reaction. We have observed a suppurative pattern of inflammation associated with infections by rapid-growing Mycobacterium species in immunocompromised patients. We report 6 cases in skin and soft tissue with an unusual but consistent lack of a predominance of granulomatous inflammation. Of the 6 cases, 4 had predominantly (approximately 75%) suppurative inflammation, 1 case predominantly demonstrated (approximately 75%) a mix of acute and chronic inflammation, and 1 case showed an approximately equal contribution of suppurative and granulomatous inflammation. All 6 cases showed abscess formation and numerous acid-fast bacilli (AFB) on AFB stain and were confirmed by tissue culture. Of these 6 cases, 2 had microabscesses with central pseudocysts harboring microorganisms. Five patients were taking oral prednisone, and 1 had an uncharacterized immunodeficiency. These cases highlight the need for awareness of this unusual manifestation of infection with rapid-growing Mycobacterium species, particularly in immunocompromised patients.
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ABSTRACT: Rapidly growing mycobacteria (RGM) cause skin infections that are refractory to standard antibiotic regimens. Although typically associated with disseminated cutaneous or other systemic infections in immunocompromised patients, RGM sometimes cause localized cutaneous infections in immunocompetent hosts. These infections are almost always associated with precedent skin trauma and inoculation, and therefore have been implicated in outbreaks involving contaminated tattoo ink and inadequately sterilized acupuncture needles. Histologic features often include suppurative granulomatous inflammation, and microorganisms are rarely visualized with stains for acid-fast bacilli. The differential diagnosis includes granulomatous fungal and non-RGM bacterial infections as well as noninfectious suppurative or sarcoidlike conditions. Because no pathognomonic histologic features exist for cutaneous RGM infections, clinical suspicion and appropriate workup are essential to reach an accurate and timely diagnosis. Most localized cutaneous RGM infections in immunocompetent individuals respond well to either clarithromycin or amikacin, in combination with surgical debridement.Archives of pathology & laboratory medicine 08/2014; 138(8):1106-9. DOI:10.5858/arpa.2012-0203-RS · 2.88 Impact Factor
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ABSTRACT: Case report A 63-year-old woman presented with multiple tender, nonulcerating, erythematous nodules on her right hand and forearm for 10 days (Figure 1A). She was suffering from Sjögren's syndrome for more than 1 year and had been treated continually with azathioprine and prednisolone. Under the tentative diagnosis of erythema nodosum, an incisional biopsy was performed on her right forearm. Histopathology showed septolobular panniculitis, heavy infiltrates of neutrophils and granulomatous inflammation (Figures 1B and 1C). Periodic acid-Schiff (PAS) and acid-fast stains were negative. She was then treated with prednisolone 20 mg per day for suspected autoimmune panniculitis. The patient returned to our clinic 2 months after initial presentation. Multiple erythematous to purpuric macules, papules, and punched out ulcers spread centripetally over the patient's four extremities in a symmetrical distribution (Figure 2A). Tender erythematous nodular eruptions without ulcerations similar to her previous skin lesions at initial presentation were found over both hands and forearms (Figure 2B). There were no associated systemic symptoms, such as fever, chilling and myalgia. She was treated with higher dose of prednisolone of up to 60 mg per day for suspected autoimmune vasculitis by the rheumatologist. However, more papulonodules, ulcers and pustules developed over her extremities as we tapered the dose of systemic steroid. Another skin biopsy of a fresh pustule from her right hand was taken and submitted for both histopathology and culture. Acid-fast positive bacilli were found (Figure 3). Figure 2 (A) Multiple crusted erythematous to purpuric macules and papules over extremities. (B) Several erythematous subcutaneous nod-ules similar to the lesions seen at initial presentation were noted over both hands and forearms. In addition, pustules and crusted lesions were seen during her second visit. A B C Figure 1 (A) Multiple tender, nonulcerating, swollen erythematous subcutaneous nodules on her right hand and forearm. (B,C) Heavy infiltrates of neutrophils and granulomatous inflammation in the subcutaneous tissue were seen. The inflammatory response was centered in the panniculus (H&E, 20×, 100×).Dermatologica Sinica 12/2010; 28(4). DOI:10.1016/S1027-8117(10)60040-7 · 0.57 Impact Factor
The American Journal of Gastroenterology 09/2014; 109(9):1501-2. DOI:10.1038/ajg.2014.209 · 9.21 Impact Factor