Primary Cutaneous Mycobacterium avium Complex Infection Following Squamous Cell Carcinoma Excision Joseph Dyer, DO; Jonathan Weiss, MD; W. Stephen Steiner, PA-C; Julie A. Barber, MD PRACTICE POINTS • Mycobacterium avium complex (MAC) is a ubiquitous bacterium that commonly infects the lungs and less commonly infects the skin. • Clinically, cutaneous MAC infection is polymorphous and may presentcopy as a nodule, plaque, or ulcer. • Standard treatment of primary cutaneous MAC includes systemic antibiotics with or without surgical excision. not Primary cutaneous Mycobacterium avium comDo- cell carcinomas (SCCs) 2 months prior. The patient plex (MAC) infection is rare, particularly among had worked in lawn maintenance for decades and immunocompetent patients. We present the continued to garden on an avocational basis. He case of a purportedly healthy patient with pri- denied exposure to angling or aquariums. mary cutaneous MAC infection arising within the On physical examination the lesions appeared excision margins of multiple infiltrating squamous as firm, dusky-violaceous, crusted nodules cell carcinomas. (Figure 1). Brown patches of hyperpigmentation or Cutis. 2016;98:E8-E11. characteristic cornlike elevations of the palm were CUTIS not present to implicate arsenic exposure. Extensive Case Report sun damage to the face, neck, forearms, and dor- A 78-year-old man presented for evaluation of sal aspect of the hands was noted. Epitrochlear 4 painful keratotic nodules that had appeared on the lymphadenopathy or lymphangitic streaking were not dorsal aspect of the right thumb, the first web space appreciated. Routine hematologic parameters includ- of the right hand, and the first web space of the ing leukocyte count were normal, except for chronic left hand. The nodules developed in pericicatricial thrombocytopenia. Computerized tomography of the skin following Mohs micrographic surgery to the abdomen demonstrated no hepatosplenomegaly or affected areas for treatment of invasive squamous enlarged lymph nodes. Hematoxylin and eosin stain- ing of biopsy specimens from the right thumb showed irregular squamous epithelial hyperplasia with an Dr. Dyer is from the Philadelphia College of Osteopathic Medicine, impetiginized scale crust and pustular tissue reaction, Suwanee, Georgia. Dr. Weiss and Mr. Steiner are from private including suppurative abscess formation in the dermis practice, Snellville, Georgia. Dr. Barber is from the Department (Figure 2). Initial acid-fast staining performed on the of Dermatopathology, Emory University School of Medicine, biopsy from the right thumb was negative for micro- Atlanta, Georgia. The authors report no conflict of interest. organisms. Given the concerning histologic features Correspondence: Joseph Dyer, DO, 625 Old Peachtree Rd NW, indicating infection, a tissue culture was performed. Suwanee, GA 30024 ([email protected]). Subsequent growth on Lowenstein-Jensen culture E8 CUTIS® WWW.CUTIS.COM Copyright Cutis 2016. No part of this publication may be reproduced, stored, or transmitted without the prior written permission of the Publisher. Mycobacterium avium Complex Infection Figure 1. Dusky-violaceous crusted nodules adjacent to Mohs micrographic surgery sites on the dorsal aspect of the right thumb and the first web space of the right and A B left hands (A and B). copy Figure 2. Biopsy of the right not thumb demonstrated irregu- lar pseudoepitheliomatous hyperplasia associated with a suppurative dermal Do infiltrate, which was highly suspicious for an infectious etiology (H&E, original mag- nification ×40). medium confirmed infection with Mycobacterium osteomyelitis, hepatosplenomegaly, or skin involve- avium complex (MAC). The patient was started on ment. Disseminated MAC infection can occur in clarithromycin 500 mg twiceCUTIS daily in accordance patients with defective immune systems, including with laboratory susceptibilities, and the cutaneous those with conditions such as AIDS or hairy cell nodules improved. Unfortunately, the patient died leukemia and those undergoing immunosuppressive 6 months later secondary to cardiac arrest. therapy.1,4 Although uncommon, cutaneous infec- tion with MAC occurs via 3 possible mechanisms: Comment (1) primary inoculation, (2) lymphogenous exten- The genus Mycobacterium comprises more than sion, or (3) hematologic dissemination.4 According 130 described bacteria, including the precipitants to a PubMed search of articles indexed for MEDLINE of tuberculosis and leprosy. Mycobacterium avium using the terms primary cutaneous Mycobacterium complex—an umbrella term for M avium, avium complex and MAC skin infection, only Mycobacterium intracellulare, and other close 11 known cases of primary cutaneous MAC infec- relatives—is a member of the genus that main- tion have been reported in the English-language tains a low pathogenicity for healthy individu- literature,4-14 the most recent being a report by als.1,2 Nonetheless, MAC accounts for more than Landriscina et al.11 70% of cases of nontuberculous mycobacterial dis- A Runyon group III bacillus, MAC is a slow- ease in the United States.3 Mycobacterium avium growing nonchromogen that is ubiquitous in nature.15 complex typically acts as a respiratory pathogen, It has been isolated from soil, water, house dust, 3 but infection may manifest with lymphadenitis, vegetables, eggs, and milk. According to Reed et al, WWW.CUTIS.COM VOLUME 98, DECEMBER 2016 E9 Copyright Cutis 2016. No part of this publication may be reproduced, stored, or transmitted without the prior written permission of the Publisher. Mycobacterium avium Complex Infection occupational exposure to soil is an independent risk neoplasms. This presentation may have been the factor for MAC infection, with individuals reporting first clinical indication of subtle immune compro- more than 6 years of cumulative participation in lawn mise. For example, inadequate proinflammatory and landscaping services, farming, or other occupa- cytokines may contribute to both mycobacterial tions involving substantial exposure to dirt or dust and malignant disease. A potential risk of inhibi- most likely to be MAC-positive. Cutaneous MAC tion of tumor necrosis factor α is the unmasking infection may be associated with water exposure, as of tuberculosis or lymphoma.19,20 Likewise, IFN-γ is Sugita et al2 described one familial outbreak of cuta- vital in suppressing mycobacteria and malignancy. neous MAC infection linked to use of a circulating, Yonekura et al21 found that IFN-γ induces apoptosis constantly heated bathwater system. With respect to in oral SCC lines. It follows that a paucity of IFN-γ US geography, individuals living in rural areas of the could allow neoplastic growth. Normal function of South seem most prone to MAC infection.3 IFN-γ prompts microbicidal activity in macrophages Primary cutaneous infection with MAC occurs and stimulates granuloma formation, both of which after a breach in the skin surface, though this fact combat mycobacterial infection.19 A final postula- may not be elicited by history. Modes of entry tion is that a simmering cutaneous MAC infec- include minor abrasions after falling,1 small wounds,2 tion precipitated neoplastic degeneration into SCC, traumatic inoculation,15 and intramuscular injec- much the same way that the human papillomavirus tion.16 Clinically, cutaneous lesions of MAC are has been correlated in the carcinogenesis of cervical protean. In the literature, clinical presentation is cancer. As an intracellular microbe, MAC could described as a polymorphous appearance with scaling cause the genetic machinery of skin cells to go awry. plaques, verrucous nodules, crusted ulcers, inflam- Kullavanijaya et al18 described a patient with cutane- matory nodules, dermatitis, panniculitis, draining ous MAC in associationcopy with cervical cancer. sinuses, ecthymatous lesions, sporotrichoid growth patterns, or rosacealike papulopustules.1,15,17 Lesions Conclusion may affect the arms and legs, trunk, buttocks, This association of primary cutaneous MAC infec- and face.18 tionnot and cutaneous malignancy in a reportedly The differential diagnosis of MAC infection immunocompetent patient is rare. Cancer patients, includes lupus vulgaris, Mycobacterium marinum as noted by Feld et al,22 are 3 times more likely to infection (also known as swimming pool granuloma), develop infections with mycobacteria, with SCC, sporotrichosis, nocardiosis, sarcoidosis, neutrophilicDo lymphoma, and leukemia being most commonly indi- dermatosis, pyoderma gangrenosum, and cutane- cated. A specific immune deficit in the IFN-γ recep- ous blastomycosis. Given its rarity and variability, tor is known to confer a selective predisposition to diagnosis of MAC infection requires a high index of mycobacterial infection.23,24 Toyoda et al25 outlined suspicion. Cutaneous MAC infection should be con- the case of a pediatric patient with IFN-γ receptor 2 sidered if a nodule, plaque, or ulcer fails to respond deficiency who presented with disseminated MAC to conventional treatment, especially in patients infection and later succumbed to multiple SCCs of with a history of environmental exposure and pos- the hands and face. The authors’ assertion was that sible injury to the skin. CUTIS inherited disorders of IFN-γ–mediated immunity We report a rare case of primary cutaneous MAC may be associated with SCCs.25 Unfortunately, our infection arising in SCC excision sites in a patient patient died before more specific immunological without known immune deficiency. This presenta- testing