BACKGROUND Birt-Hogg-Dubé syndrome (BHDS) is a rare autosomal dominant genodermatosis characterized by benign growth of the hair follicles, the presence of pulmonary cysts, spontaneous pneumothorax, and bilateral renal tumors that are usually hybrid oncocytic or multifocal chromophobe renal cell carcinoma. The diagnosis is confirmed by the presence of a pathogenic variant in the tumor suppressor folliculin (FLCN) gene mapped at 17p11.2. Although the dermatological lesions typical of BHDS are benign and only cause aesthetic concerns, and the pulmonary manifestations are controllable, the greater tendency of patients with this syndrome to present benign or malignant renal tumors, often bilateral and multifocal, makes the diagnosis of this syndrome important for the prognosis of the patients. The objective was to report the case of a patient with BHDS, without pulmonary manifestations and with hyperplastic polyposis of the gastrointestinal tract, and to perform a literature review. CASE PRESENTATION A 60-year-old man complained of abdominal pain and diarrhoea for 2 months. Physical examination was normal except for the presence of normochromic papules in the frontal region of the face associated with hyperkeratotic and hyperchromic papules in the dorsal region. The excisional biopsies of the skin lesions indicated trichodiscomas. Esophagogastroduodenoscopy, enteroscopy, and colonoscopy showed the presence of hyperplastic polyps in the stomach, duodenum, jejunum, colon, and rectum. Computed tomography (CT) and magnetic resonance imaging (MRI) of the abdomen revealed multiple expansive solid lesions in both kidneys, with necrotic and calcified areas. Renal magnetic resonance angiography also showed a solid lesion in the right kidney measuring 5 cm in diameter and another solid lesion in the left kidney measuring 8 cm in diameter, both suggestive of renal angiomyolipoma. CT scans of the skull, chest, and temporal bones were normal. The genetic study revealed the presence of a variant of FLCN in the intron 13. CONCLUSIONS To the best of our knowledge, this is the first reported case of BHDS with the simultaneous finding of gastrointestinal hyperplastic polyposis, which may represent a possible phenotypic expression of this syndrome that has not yet been described.

中文翻译：

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Birt-Hogg-Dubé 综合征伴胃肠道同时增生性息肉病：病例报告和文献回顾。

背景 Birt-Hogg-Dubé 综合征 (BHDS) 是一种罕见的常染色体显性遗传皮肤病，其特征是毛囊良性生长、存在肺囊肿、自发性气胸和双侧肾肿瘤，通常是混合嗜酸细胞或多灶性嫌色肾细胞癌。诊断通过在 17p11.2 定位的肿瘤抑制滤泡蛋白 (FLCN) 基因中存在致病性变异来证实。虽然 BHDS 典型的皮肤病学病变是良性的，仅引起美观问题，并且肺部表现是可控的，但该综合征患者出现良性或恶性肾肿瘤（通常为双侧和多灶性）的更大趋势，使得该综合征的诊断很重要用于患者的预后。目的是报告一例没有肺部表现和胃肠道增生性息肉病的 BHDS 患者的病例，并进行文献回顾。病例介绍 一名 60 岁的男性主诉腹痛和腹泻 2 个月。体格检查正常，但面部前部出现正常色素性丘疹，并伴有背部过度角化和深色素性丘疹。皮肤损伤的切除活检表明有毛滴虫。食管胃十二指肠镜、小肠镜和结肠镜检查显示胃、十二指肠、空肠、结肠和直肠存在增生性息肉。腹部计算机断层扫描 (CT) 和磁共振成像 (MRI) 显示双肾多处扩大的实性病变，有坏死和钙化区域。肾磁共振血管造影还显示右肾有一个直径为 5 cm 的实性病变，左肾有另一个直径为 8 cm 的实性病变，均提示肾血管平滑肌脂肪瘤。颅骨、胸部和颞骨的 CT 扫描正常。遗传研究显示内含子 13 中存在 FLCN 的变体。 结论 据我们所知，这是首例报告的 BHDS 病例，同时发现胃肠道增生性息肉病，这可能代表了这种可能的表型表达。尚未描述的综合征。均提示肾血管平滑肌脂肪瘤。颅骨、胸部和颞骨的 CT 扫描正常。遗传研究显示内含子 13 中存在 FLCN 的变体。 结论 据我们所知，这是首例报告的 BHDS 病例，同时发现胃肠道增生性息肉病，这可能代表了这种可能的表型表达。尚未描述的综合征。均提示肾血管平滑肌脂肪瘤。颅骨、胸部和颞骨的 CT 扫描正常。遗传研究显示内含子 13 中存在 FLCN 的变体。 结论 据我们所知，这是首例报告的 BHDS 病例，同时发现胃肠道增生性息肉病，这可能代表了这种可能的表型表达。尚未描述的综合征。