1/12. Cutaneous malignancy in albinism.albinism is a disorder of hypopigmentation affecting the skin, appendages, and eyes. Ultraviolet light-induced cutaneous tumors are common in patients with albinism due to reduced or absent protection from melanin. Squamous cell carcinoma (SCC) is the number one skin tumor seen in patients who are albinos. Although nonmelanomatous skin cancers are more common in patients with albinism, dysplastic nevus and melanoma present a greater diagnostic challenge in this group because of their hypopigmented appearance. We report 2 cases of cutaneous malignancies in patients who had oculocutaneous albinism (OCA). The first case involves a 45-year-old man with OCA type 2 (OCA2) who developed a large SCC of the neck. The second case involves a 24-year-old man with Hermansky-Pudiak syndrome (HPS) who developed amelanotic melanoma. In both cases, hypopigmentation of the lesions contributed to a delay in diagnosis. We review the clinical, diagnostic, and therapeutic concerns for patients with albinism who have cutaneous malignancies.- - - - - - - - - - ranking = 1keywords = pigmented (Clic here for more details about this article) |
2/12. Oculocutaneous albinism: variable expressivity of nystagmus in a sibship.Traditionally, the diagnosis of ocular or oculocutaneous albinism (OCA) is based on a constellation of features including the presence of nystagmus associated with iris transillumination defects, hypopigmentation of the fundus, and hypoplasia of the fovea and optic nerve head. Nystagmus is the most frequent ocular sign for the ascertainment of albinism particularly in individuals who have lightly-pigmented parents. We report two siblings, a male and female, with minimal, if any, pigmentation of skin and hair, iris transillumination defects, blond fundi, and hypoplasia of the foveae and optic nerve heads who were discordant for nystagmus; the diagnosis of OCA was based on the clinical findings. These siblings presumably have the same genetic hypopigmentation defect and demonstrate that nystagmus is not a consistent finding in OCA and may not be an absolute criterion for diagnosis.- - - - - - - - - - ranking = 1keywords = pigmented (Clic here for more details about this article) |
3/12. Do pigmented naevi in albinism provide evidence of tyrosinase positivity?We investigated a 4-year-old Japanese boy with oculocutaneous albinism who had a solitary pigmented mole measuring 5 mm in diameter on his back. An electron microscopic tyrosine incubation test and a DOPA reaction test clearly demonstrated the presence of tyrosinase activity in the patient's hypopigmented skin. The presence of tyrosinase activity was confirmed by tests on hair bulb samples. Histopathological evidence showed that the mole was a typical compound cellular naevus with melanin pigmentation. Although no reports to date have focused on the relationship between pigmented naevi in albinism and tyrosinase activity, our findings suggest that the occurrence of pigmented naevi in an albino may indicate the presence of tyrosinase activity.- - - - - - - - - - ranking = 12.665029585934keywords = naevus, pigmented (Clic here for more details about this article) |
4/12. Choroidal malignant melanoma in an albino.This is the first report of an amelanotic melanoma arising in the unpigmented choroid of a tyrosinase-positive oculocutaneous albino (TPOCA). melanosomes within the tumour showed a maturation arrest in the unpigmented type II (premelanosome) phase. Other neural crest derived melanocytes in iris and choroid showed similar limited melanogenesis. The neuroectodermally derived melanocytes of the iris, ciliary body, and retinal pigment epithelium (RPE) contained mature melanosomes, though clinically the RPE was pale. The significance of this tumour arising in an albinotic eye is discussed.- - - - - - - - - - ranking = 2keywords = pigmented (Clic here for more details about this article) |
5/12. Nettleship-Falls X-linked ocular albinism with Axenfeld's anomaly. A case report.A Japanese male with Nettleship-Falls X-linked ocular albinism (NXOA) and associated with Axenfeld's anomaly is described here. The diagnosis of X-linked ocular albinism was difficult because of moderately pigmented fundus and lack of iris translucency, but macromelanosomes recognized by histological study of skin biopsy were helpful for diagnosis. This is the first report identifying the macromelanosomes in Japanese NXOA. A combination of ocular albinism and Axenfeld's anomaly is very rare. There might be a common defective factor for the development of these two congenital disorders.- - - - - - - - - - ranking = 1keywords = pigmented (Clic here for more details about this article) |
6/12. Hermansky-Pudlak syndrome with special reference to lysosomal dysfunction. A case report and review of the literature.In addition to the triad in the Hermansky-Pudlak syndrome (tyrosine-positive oculocutaneous albinism, mild bleeding tendency with a normal platelet-count and widespread accumulation of ceroid-like pigment in various organs), we document severe pulmonary fibrosis, pseudomelanosis coli and deeply pigmented renal cortex. In the liver, innumerable number of pigment-laden kupffer cells and macrophages in the Glisson capsule were seen. Interestingly, many intralysosomal accumulations of the pigment within the hepatocytes were found by electron microscopy, suggesting that these configurations possibly resulted from a dysfunction of the lysosome itself, especially with regard to loss of digestive and secretory activity. The triad and other complications may also be resultants of a lysosomal dysfunction.- - - - - - - - - - ranking = 1keywords = pigmented (Clic here for more details about this article) |
7/12. The melanin pigmentary disorder in a family with Hermansky-Pudlak syndrome.The albinotic skin and hair of 2 patients with Hermansky-Pudlak syndrome were investigated by light and electron microscopy. Incubation of hairbulbs and epidermis in 1-dopa revealed a weak tyrosinase activity. The epidermal melanocyte population was of normal density. The most striking feature was the presence of numerous giant melanosomes resembling those mainly reported in various hyperpigmented skin lesions. The association of this melanosomal disorder with the platelet dysfunction and ceroid storage typical of the autosomal recessive Hermansky-Pudlak syndrome might provide new insights into the mechanism leading to formation of giant melanosomes.- - - - - - - - - - ranking = 1keywords = pigmented (Clic here for more details about this article) |
8/12. A syndrome associating partial albinism and immunodeficiency.Two unrelated patients with partial albinism, frequent pyogenic infections and acute episodes of fever, neutropenia and thrombocytopenia are described. Their pigmentary dilution was characterized by large clumps of pigments in the hair shafts and an accumulation of melanosomes in melanocytes. melanocytes had few short dendritic expansions, and keratinocytes were hypopigmented. No or few Langerhans' cells were detected in skin by electron microscopy and ATP-ase reactions. This pigmentary dilution, different from all other human albinisms, resembles the unique defect of the mutant dilute (d-d) mouse. Despite the presence of an adequate number of T and B lymphocytes, the patients were hypogammaglobulinemic, deficient in antibody production and incapable of manifesting delayed skin hypersensitivity or of rejecting skin grafts. Their leukocytes did not stimulate normal lymphocytes and could not generate cytotoxic cells during mixed leukocyte reaction. T lymphocytes of one patient were unable to exert a helper effect on the maturation of B lymphocytes into immunoglobulin-containing cells following in vitro stimulation with pokeweed mitogen. This suggests that the humoral deficiency might be secondary to a defect of helper T lymphocytes. granulocytes did not show any morphologic abnormality, and their bactericidal activity was only moderately reduced. An increased number of polymorphonuclear leukocytes with polar distribution of Concanavaline A (Con A) receptors (capping) was found in one patient and her parents. The family histories suggest that this syndrome is transmitted as an autosomal recessive character.- - - - - - - - - - ranking = 1keywords = pigmented (Clic here for more details about this article) |
9/12. lentigo maligna in a woman with oculocutaneous albinism.A 54-year-old black woman with oculocutaneous albinism was found to have a lentigo maligna and, subsequently, a pigmented compound nevus on non-sun-exposed areas of her body. The diagnosis for these lesions was confirmed by the results of histopathologic study. To our knowledge, this is the first such case reported in the literature. This patient reemphasizes the fact that melanoma development is dependent on the presence of melanocytes, but not necessarily on melanogenesis. We propose that the rarity of melanomas in these patients may be caused by the protective effect of unknown systemic factors.- - - - - - - - - - ranking = 1keywords = pigmented (Clic here for more details about this article) |
10/12. The Hermansky-Pudlak syndrome. Evidence for a lowered 5-hydroxytryptamine content in platelets of heterozygotes.A Dutch kindred with the Hermansky-Pudlak syndrome (HPS) is described. We show for the first time evidence of a lowered platelet 5-hydroxytryptamine content in obligate heterozygotes. Platelet ATP and ADP levels and ATP/ADP ratio were normal in these patients. platelet aggregation with ADP, collagen and adrenaline was within the normal range. In contrast to the homozygous HPS patients the heterozygotes are normally pigmented and none has diaphanous irides, nystagmus or a bleeding tendency. All homozygous HPS patients have the typical triad of oculocutaneous albinism, pigmented macrophages in the bone marrow and a bleeding disorder, based on a platelet dysfunction. The platelets showed the typical characteristics of a storage pool deficiency. Their platelet factor 3 availability was decreased and the aggregation patterns showed an absent second wave with ADP, adrenaline and absent collagen aggregation. Platelet ADP levels were strongly decreased in all homozygous HPS patients, whereas ATP was lowered only in 3 out of 6 HPS patients. The 5-hydroxytryptamine content of their platelets was very low (15-20% of normal).- - - - - - - - - - ranking = 2keywords = pigmented (Clic here for more details about this article) |
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