Atypical radiographic presentations of pulmonary sarcoidosis occur in 15–25% of patients [
3]. These findings can include diffuse ground-glass opacities, honeycombing, multiple nodules, or necrotizing consolidations [
3]. A large, solitary lung mass, as described in our patient’s case, has rarely been reported, and its incidence is unknown; it is likely to be the result of individual granulomas that have coalesced to produce the appearance of a mass [
5].
Because solitary lung masses with mediastinal lymphadenopathy are the hallmarks of lung cancer, obtaining a definitive diagnosis in cases of atypical pulmonary sarcoidosis is diagnostically challenging. Prior case reports described the need for a surgical lung biopsy to obtain sufficient tissue for a definitive diagnosis [
4,
6], which was the case in our patient. However, the presence of granulomas does not necessarily rule out a malignancy, because non-caseating granulomas have been reported in some instances of small cell lung cancer [
7]. Moreover, the presence of non-caseating granulomas in association with a malignancy, described as a sarcoid-like reaction, has been shown to occur adjacent to the site of the malignancy or around local lymph nodes [
7,
8]. Sarcoid-like reactions, which are histologically indistinguishable from granulomas found in usual cases of sarcoidosis, are believed to be the result of an immunological response to local tumor products [
8]. They occur in the context of both hematologic malignancies and solid tumors; one study demonstrated an association between sarcoid-like reactions and lung cancer [
8]. In addition, sarcoid-like reactions occur in response to microbial infection, such as leishmaniasis, tuberculosis, and coccidioidomycosis [
9]. Thus, in cases of atypical sarcoidosis, biopsies from two noncontiguous sites are recommended to rule out an active malignancy or infection [
10].
Although prednisone is the first-line treatment for sarcoidosis [
1,
2], in cases with significant adverse reactions, such as the one presented here, steroid-sparing agents can be considered. Methotrexate is a commonly chosen second-line agent because it has been shown to be effective in decreasing the necessary dose of prednisone when used in combination [
11]. For refractory cases, leflunomide and tumor necrosis factor-α antagonists, such as infliximab, adalimumab, or etanercept, have demonstrated efficacy in small observational studies [
11,
12].