1/4. Dowling-Degos disease associated with squamous cell carcinomas on the dappled pigmentation.We report the first case of Dowling-Degos disease associated with squamous cell carcinomas (SCCs) in the pigmented area of Dowling-Degos disease. A 64-year-old Japanese man manifested dappled pigmentation unusually localized to the buttocks, and two pigmented adenoid SCCs had developed on his left pigmented buttock. The other findings of Dowling-Degos disease were comedone-like lesions on the face and back, a finger-like fibroma in the right popliteal fossa, dystrophic fingernails, and a large number of seborrhoeic keratosis-like lesions predominantly on the flexural areas. Another unique clinical feature was the lack of vellus hair on the whole body surface. In addition to thin branching and elongation of rete ridges with basal hyperpigmentation, immature hair follicles surrounded by fibrosis and a lace-like pattern of the hair follicle epithelia were observed histologically. These epithelial hamartomatous features were consistent with Dowling-Degos disease. We speculate that the SCCs developed in relation to an underlying naevoid anomaly in pilosebaceous epithelia of Dowling-Degos disease.- - - - - - - - - - ranking = 1keywords = hyperpigmentation (Clic here for more details about this article) |
2/4. Late recurrence of inflammatory first-stage lesions in incontinentia pigmenti: an unusual phenomenon and a fascinating pathologic mechanism.BACKGROUND: incontinentia pigmenti (IP) is an X-linked genodermatosis that is manifested by neonatal inflammatory vesicles localized along the lines of Blaschko. These lesions usually clear spontaneously within a few months, leaving hyperpigmentation. Ophthalmologic and neurologic symptoms can be associated with IP. Late recurrences of the first-stage inflammatory lesions after the initial rash are uncommon and have been reported infrequently. The mechanism involved in this phenomenon is unclear. However, the recent identification of NEMO/IKKgamma as the gene responsible for IP sheds new light on its pathophysiologic origins. OBSERVATIONS: We report 5 cases of children who experienced episodes of late reactivation of IP. In all cases, the recurrences occurred on the previously hyperpigmented streaks several months or years after resolution of the initial eruptions. In most cases, the recurrences were preceded by an infectious episode. CONCLUSIONS: These IP recurrences suggest that mutated cells can persist a long time in the epidermis. We theorize that infections trigger the reactivations. The NEMO/IKKgamma gene encodes a protein essential in nuclear factor kappaB activation, which is required for resistance to tumor necrosis factor alpha-induced apoptosis. We discuss the role of a proinflammatory cytokine such as tumor necrosis factor alpha as a triggering factor for the reactivation.- - - - - - - - - - ranking = 1keywords = hyperpigmentation (Clic here for more details about this article) |
3/4. A study of immunohistochemical and electron microscopic changes in Dowling-Degos disease.Previous investigations have focused on the skin manifestations, histopathology, and pedigree of patients with Dowling-Degos disease (DDD). Little is known about its immunohistochemical staining, and electron microscopy. Our purpose was to study the immunohistochemistry and electron microscopy of lesions from patients with DDD. A biopsy specimen revealed elongated epidermal rete ridges with basilar hyperpigmentation in a filiform pattern. All pigmented cells in the basal layer were recognized by Anti-PEP-1, anti-PEP-2, HMB-45 and NKI/beteb antibodies. The melanocytes were localized in the basal layer and accounted for 10% of the total keratinocytes. There were supranuclear "caps" of brown granules within most basal kerotinocytes in the hyperpigmentation area. The melanocytes contained many mitochondria, Golgi apparati, and regular melanosomes in all stages of maturation in their cytoplasms; melanosome-laden dendrites were readily detected by transmission electron microscepe. melanosomes, mainly of stages III and IV, were present within keratinocytes, distributed either as scattered patterns or forming "caps" over the nucleus.- - - - - - - - - - ranking = 2keywords = hyperpigmentation (Clic here for more details about this article) |
4/4. skin manifestations in a case of trisomy 16 mosaicism.We present a 48-year-old man with unilateral dermatological manifestations including hypertrichosis, telangiectasia, hyperkeratosis and hyperpigmentation. Additional findings included skeletal abnormalities and left-sided hearing loss. Skin biopsies showed changes characteristic of porokeratosis. Fibroblast karyotyping from affected skin demonstrated trisomy 16 mosaicism, in contrast to the normal karyotype in unaffected skin and blood lymphocytes. The possible role of trisomy 16 in porokeratosis is discussed.- - - - - - - - - - ranking = 1keywords = hyperpigmentation (Clic here for more details about this article) |