ABSTRACT
Mucosal melanomas are rare and only a small portion bear BRAF mutations while cutaneous melanomas have a much higher prevalence and often harbor BRAF mutations. We present two cases in which, after a malignant melanocytic mucosal lesion with a BRAF mutation was found, the primary cutaneous source was identified and clonality confirmed between the lesions. In both cases, primary lesions occurred on the scalp, an often-overlooked site. Both lesions showed signs of regression implying that in due time these lesions could have been fully regressed and might never have been detected. In that case, the metastatic mucosal lesion would erroneously be identified as a BRAF-mutated mucosal melanoma. These cases give warrant; a careful dermatological inspection should be instigated when confronted with a BRAF-mutated mucosal melanoma. We hypothesize that some BRAF-mutated mucosal melanomas might actually represent metastases of regressed cutaneous melanomas.
Subject(s)
Melanoma , Skin Neoplasms , Humans , Melanoma/genetics , Melanoma/pathology , Mutation , Proto-Oncogene Proteins B-raf/genetics , Scalp/pathology , Skin Neoplasms/genetics , Skin Neoplasms/pathologyABSTRACT
BACKGROUND: TOX (thymocyte selection-associated high-mobility group box) was shown to be aberrantly expressed in mycosis fungoides (MF) and Sézary syndrome (SS) and is suggested to have additional diagnostic value. However, data on expression in other types of cutaneous T-cell lymphoma (CTCL) are scarce and it is unknown whether TOX is expressed only by MF with a CD4(+) CD8(-) phenotype. OBJECTIVES: To investigate TOX expression in various types of CTCL with different T-cell phenotypes. METHODS: Immunohistochemical expression of TOX was evaluated on 153 skin biopsies of 132 patients with CTCL and 60 patients with benign inflammatory dermatoses (BIDs). RESULTS: TOX was expressed by > 50% of the neoplastic T cells in 49 of 59 patients (83%) with MF and in 19 of 22 patients (86%) with SS. The TOX(+) cases of MF included 34 of 35 cases (97%) with a CD4(+) CD8(-) phenotype, but also five of eight cases (63%) with a CD4(-) CD8(+) phenotype and 10 of 16 cases (63%) with a CD4(-) CD8(-) phenotype. TOX expression in other types of CTCL was common but showed variable intensity. Although only one of 60 patients (2%) with a BID expressed TOX in > 50% of the skin-infiltrating T cells, some caution is warranted, as the majority of BIDs had TOX(+) T cells varying between 11% and 50%. CONCLUSIONS: TOX expression is not tumour specific, is not restricted to CTCL with a CD4(+) CD8(-) phenotype, and, on its own, is insufficient for diagnosis of CTCL. However, it may have an adjunctive diagnostic role in conjunction with other clinical and histological data.
Subject(s)
Biomarkers, Tumor/metabolism , High Mobility Group Proteins/metabolism , Lymphoma, T-Cell, Cutaneous/diagnosis , CD4-Positive T-Lymphocytes/metabolism , CD8-Positive T-Lymphocytes/metabolism , Diagnosis, Differential , Humans , Mycosis Fungoides/diagnosis , Phenotype , Sezary Syndrome/diagnosisABSTRACT
BACKGROUND: Due to a great diversity of clinical presentations secondary syphilis can mimic various skin diseases, which means that the diagnosis of this sexually transmitted condition can be missed. Occurrence of a granulomatous inflammatory reaction in secondary syphilis is rare and may be confused with other granulomatous dermatoses. CASE DESCRIPTION: We present a 37-year-old homosexual male with a granulomatous dermatitis due to secondary syphilis. The differential diagnosis based on clinical and histopathological findings was lengthy and the initial syphilitic serology results were negative, resulting in delayed diagnosis. After revision of the histopathology and repeated serological testing secondary syphilis could be diagnosed. CONCLUSION: Not only the clinical, but also the histopathological presentation of secondary syphilis is variable. To prevent transmission, treatment delay and complications, we recommend repeating syphilitic serology following negative results if there is clinical or histopathological suspicion of this disease, especially in patients displaying high-risk behaviour. Syphilis should be also excluded in granulomatous dermatoses with plasma cells.
