{"id":385139,"date":"2024-10-30T00:01:00","date_gmt":"2024-10-29T23:01:00","guid":{"rendered":"https:\/\/medizinonline.com\/?p=385139"},"modified":"2024-10-30T21:03:53","modified_gmt":"2024-10-30T20:03:53","slug":"fibrofolliculomas-as-indicator-lesions","status":"publish","type":"post","link":"https:\/\/medizinonline.com\/en\/fibrofolliculomas-as-indicator-lesions\/","title":{"rendered":"Fibrofolliculomas as indicator lesions"},"content":{"rendered":"\n

The vast majority of patients affected by this rare hereditary tumor syndrome develop numerous fibrofolliculomas in middle age, particularly on the face and upper body.\nGenetic testing is required to confirm the diagnosis of Birt-Hogg-Dub\u00e9 syndrome.\nAffected patients should be referred to a lung and kidney specialist and to genetic counseling. <\/strong><\/p>\n\n\n\n

The cutaneous features of the disease and the autosomal dominant inheritance mechanism were described in 1977 by three Canadian physicians (Birt, Hogg, Dub\u00e9) [1].\nSubsequently, numerous case reports showed that there could be an association with renal tumors, pulmonary cysts and the occurrence of spontaneous pneumothorax.\nThe prevalence of Birt-Hogg-Dub\u00e9 syndrome (BHD) is estimated at 1:200,000, but the exact incidence is unknown [2].\nThe cause of BHD is a mutation of the FLCN gene at gene locus 17p11.2.\nThe gene codes for folliculin.\nThe exact function of this protein is currently still the subject of basic research.\nHowever, it is assumed that FLCN plays a role as a tumor suppressor protein.\nThe diagnosis of BHD is confirmed by molecular biological detection of the gene mutation.\nThe distribution and morphology of the cysts on imaging can be indicative.\nTypically, the lung cysts have thin walls and are located in the basal, subpleural and paramediastinal sections of the lung. <\/p>\n

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Cutaneous and extracutaneous manifestations <\/h2>\n\n

The characteristic skin changes in BHD are fibrofolliculomas.\nThey appear as multiple, 2-5 mm large, whitish-yellowish efflorescences that do not cause itching [1].\nThe exact clinical picture is variable – the tumors can appear as relatively inconspicuous plaques or as larger papules with a horny plug that resemble comedones or small epidermoid cysts.\nHistologically, they are circumscribed fibroblast nests with an accumulation of collagen around deformed hair follicles, from which basaloid cells extend into the surrounding tissue.\nTypically, the efflorescences usually occur on the face, neck and upper body.\nThe number of tumors and their size increase over time.\nOther common skin findings are angiofibromas and acrochordons. <\/p>\n\n

The possible extracutaneous manifestations of BHD are manifold [1]: <\/p>\n\n