Birt-Hogg-Dube Syndrome, a Rare Case in Korea Confirmed by Genetic Analysis

Simple benign tumors can present as part of a syndrome with substantial mortality. Fibrofolliculomas are benign skin tumors most often associated with the Birt-Hogg-Dube syndrome (BHDS). The most life-threatening complication of this syndrome is renal cancer and other major features include multiple lung cysts and spontaneous pneumothorax. We present the case of a 54 year-old man with multiple flesh-colored papules on his face confirmed histologically as fibrofolliculomas. He had a history of recurrent pneumothorax and chest computed tomography showed multiple lung cysts. To confirm the diagnosis of BHDS, we conducted gene analysis that revealed a single nucleotide duplication in the folliculin (FLCN) gene (Exon 11, C.1285dupC). BHDS confirmed by the FLCN gene mutation is rarely reported in Korea. Appropriate investigation is recommended whenever a patient with benign skin tumors is encountered.

Annular Lupus Vulgaris Mimicking Tinea Cruris

Cutaneous tuberculosis is an infrequent form of extrapulmonary tuberculosis. It is often clinically and histopathologically confused with various cutaneous disorders. A 36-year-old man attended our clinic with slowly progressive, asymptomatic, annular skin lesions on both the thighs and buttocks for 10 years. He consulted with many physicians and was improperly treated with an oral antifungal agent for several months under the diagnosis of tinea cruris, but no resolution of his condition was observed. A diagnosis of lupus vulgaris was made based on the histopathologic examination and the polymerase chain reaction assay. Anti-tuberculosis therapy was administered and the lesions started to regress.

A Case of Cutaneous Inflammatory Myofibroblastic Tumor

Pseudo-inflammatory tumors are also known as plasma cell granuloma, inflammatory pseudo-tumor and inflammatory myofibroblastic tumor, and these tumors are a group of highly variable proliferations of myofibroblastic cells that are associated with a prominent inflammatory infiltrate. This tumor is known to most commonly occur in the lungs, bladder and gastrointestinal system with only a few cases having been reported in the skin. A previously healthy 26-year-old man presented with a 6-year history of an intermittently pruritic lesion on his back. On the histologic examination, there were spindle cells in fascicles and a mixed inflammatory cellular infiltrate of plasma cells and lymphocytes. A diagnosis of inflammatory fibroblastic tumor was made and the nodule was surgically removed. We report here on an additional case of this rare cutaneous entity, and it is probably the first such report from Korea.