Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “MELANOSIS”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 109 records · Page 6Linked to original sources

MR of neurocutaneous melanosis.

PURPOSE: To describe the MR findings of neurocutaneous melanosis in the brain and correlate these with the known pathology and proposed embryologic basis of this disorder. METHODS: The brain (seven patients) and spine (three patients) MR scans of seven patients with neurocutaneous melanosis were retrospectively reviewed. In two patients, findings were confirmed at surgery. The pattern of central nervous system involvement was also correlated with known pathologic studies regarding frequency and location of melanotic deposits. RESULTS: Five patients had regions of T1 shortening in the cerebellum; three of these also had T2 shortening. Five patients had regions of T1 shortening in the anterior temporal lobes. Other areas of involvement included the pia mater over the cerebellum (two patients), pons (one patient), medulla (one patient), and left parietal lobe (one patient). Only two lesions showed enhancement, edema, or necrosis; both were proved malignant melanomas at biopsy. No pial enhancement was detected. CONCLUSION: Neurocutaneous melanosis appears to involve the brain in specific locations that can be detected on MR imaging. Knowledge of these locations can aid in differentiating metastases, secondary to malignant degeneration of the large cutaneous nevi, from melanotic deposits that are a part of the disease. Identification of malignant degeneration of the melanotic deposits is difficult; at present, it depends on the identification of growth, edema, or necrosis of the deposits.

Adolescent↗

THERAPY OF CHLORPROMAZINE MELANOSIS: A PRELIMINARY REPORT.

Melanosis observed in association with prolonged chlorpromazine therapy has become a serious problem in mental institutions. Skin pigmentation has produced an appearance which is cosmetically undesirable. Ocular deposits have caused visual impairment. Diffuse visceral involvement has been accompanied by functional disturbances of the involved organs.Withholding chlorpromazine did not diminish the pigment deposits already present in eight patients with chlorpromazine-induced melanosis. Therefore therapy for existing cases and means of preventing this side effect were investigated. A method of blocking melanin synthesis by depressing tyrosinase activity was devised. A copperchelating agent, D-penicillamine, was administered for a period of four weeks (300 mg. three times daily for six days each week, with mineral supplement substituted on the seventh day). Four of six days patients thus treated improved markedly as evidenced by diminution of skin pigmentation. Urinary copper excretion was substantially increased during the trial period. An alternative method of treatment designed to stimulate melatonin production by the pineal gland was employed. Two patients were kept in darkness for a period of four weeks. One improved markedly, the other only slightly.

Body Fluids↗

Posterior corneal pigmentation in melanosis oculi.

A 5-year-old girl was seen with findings consistent with melanosis oculi and notably decreased vision secondary to dense corneal pigmentation. A penetrating keratoplasty was performed without complications. Light microscopy disclosed dense pigment granules layered in deep stroma just anterior to Descemet's membrane. Electron microscopy revealed these to be melanocytes, without evidence of phagocytic activity. The corneal pigmentation may have resulted from a misdirection of melanocytes in embryogenesis. To our knowledge, the finding of visually notable corneal pigmentation has not been previously reported in association with the syndrome of melanosis oculi.

Child, Preschool↗

Melanosis oculi. An ultrastructural study of an affected iris.

The iris of a patient with melanosis oculi was studied, using the transmission electron microscope. An unusual form of macromelanosome was found within the cytoplasm of stromal melanocytes. It is possible that these structures were formed as a result of inappropriate production of the individual subunits of the melanosome. Their presence within stromal melanocytes, but not within the cells of the posterior pigment epithelium, was in keeping with the hypothesis that melanosis oculi is a disorder of melanocytes derived from neural crest.

Aged↗

Use of mitomycin C in the treatment of conjunctival primary acquired melanosis with atypia.

A patient who had primary acquired melanosis with marked atypia shown on histological studies received topical 0.02% mitomycin C for 2 weeks and 0.04% mitomycin C for an additional 2 weeks. Conjunctival biopsy specimens were obtained to evaluate the efficacy of the treatment. After the first course of mitomycin C administration, some decrease of conjunctival pigmentation was seen, and histological studies disclosed a lower degree of atypia. After the second application of mitomycin C, the pigmentation disappeared except for one small spot that contained only a few typical melanocytes on histological study. The clinical findings did not change during 7 months of follow-up. No adverse reactions to topical mitomycin C occurred except for mild conjunctival hyperemia at the end of the courses of treatment. Administration of topical mitomycin C may be an effective medical treatment for primary acquired melanosis with atypia.

Administration, Topical↗

Generalized melanosis complicating disseminated malignant melanoma in pregnancy: a case report.

A case of generalized melanosis complicating disseminated malignant melanoma in pregnancy is described. Four features of this case, unique in combination, are discussed. First, generalized melanosis is a rare complication in macrophages of skin and other areas. Secondly, extensive bone lesions in the absence of roentgenographic changes are an uncommon occurrence. Thirdly, pregnancy probably has little effect on the course of melanoma, as illustrated by this case and a review of the literature. Finally, placental metastases may be more common than generally thought, yet may have little significance to the fetus.

Adult↗

Maturation of cerebellar neuroblastoma into ganglioneuroma with melanosis. A histologic, immunocytochemical, and ultrastructural study.

A ganglioneuroma with areas of melanosis was resected from the cerebellum of a 6.5-year-old girl. At 2.5 years of age, she was diagnosed to have cerebellar neuroblastoma, which was incompletely resected and then radiated. Histologic, ultrastructural, and immunocytochemical studies undertaken on tissue from both stages of the tumor demonstrated a neuroblastic origin and differentiation into a predominantly neuronal tumor with limited astroglial participation. In addition, widespread deposition of basal lamina material, perineuronal distribution of S-100 protein-bearing cells and melanosis were found. The various features and unusual biology of the tumor are discussed in the light of a review of the literature.

Cerebellar Neoplasms↗

Peritoneal implantation of meningeal melanosis via ventriculoperitoneal shunt: a case report and review of the literature.

Systemic spread of primary intracranial neoplasms is rare and may be due to ventriculoperitoneal shunt (VPS). The most common tumors to metastasize via VPS are germinoma of the pineal gland and medulloblastoma. We report a case of 16-yr-old girl with central nervous system malignant melanosis who developed subsequent peritoneal implants via VPS. To the best of our knowledge, this patient represents the third reported case of meningeal melanosis or melanoma which metastasized to the peritoneal cavity via VPS. The VPS should be considered as possible mode of systemic spread in patients with primary cranial malignancy.

Adolescent↗

Neurocutaneous melanosis associated with intraspinal lipoma.

A case of neurocutaneous melanosis developing a leptomeningeal melanoma is described in a ten year old girl in whom an intraspinal lipoma had been resected seven years earlier. Standard and CT myelographic findings are described and the complementary role of Gadolinium-enhanced MRI is discussed. The literature is reviewed and the association of a lipoma and neurocutaneous melanosis has not been encountered.

Evaluation Studies as Topic↗

[Melanosis cerebelli. Ultrastructure and infrared absorption of the pigment (author's transl)].

The pigment present in melanosis cerebelli where it is deposited in the dentate nucleus and within the cerebellar granular layer is similar to that of S. nigra as judged from the typical infrared absorption bands near wave numbers 3.450 cm-1 and 1.650 cm-1, respectively. According to electron microscopic findings, this type of melanin arises within the astrocytes of the dentate nucleus. The astrocytic melanosomes exhibit a relatively monotonous substructure reaching diameters of 30 mu and more, and they differ in this respect from the triadic neuronal melanosomes of S. nigra that are strongly reminiscent of lipofuscin granules. These differences may be due to additional components of melanosomes, apparently specific of a particular cell type, and they are in turn accounted for by the dissimilar cellular metabolic make-up of nigral cells and astrocytes, respectively. This does not dismiss the possibility, however, that the melanin pigments of either type of melanosomes are the same or closely related to each other as far as their basic chemical composition is concerned. The cause of the melanosis of the dentate nucleus is not known. Possibly involutional tissue changes governed by endocrine factors among others may play an important part.

Aged↗

Neurocutaneous melanosis.

BACKGROUND: Neurocutaneous melanosis (NCM) is a rare phakomatosis characterized by a focal or diffuse proliferation of melanin-producing cells in both the skin and the leptomeninges. This syndrome is believed to result from an error in the morphogenesis of embryonal neuroectoderm. FEATURES: Two-thirds of patients with NCM have giant congenital melanocytic nevi, and the remaining third have numerous lesions but no giant lesions. Most patients present neurological manifestations early in life, which can be secondary to intracranial hemorrhages, to impairment of cerebrospinal fluid circulation, and to malignant transformation of the melanocytes. PROGNOSIS: The prognosis of patients with symptomatic neurocutaneous melanosis is extremely poor, even in the absence of malignancy. Chemotherapy has been ineffective in the few patients in whom it has been tried.

Case-Control Studies↗

Neurocutaneous melanosis with associated Dandy-Walker complex.

CASE REPORT: The authors report the case of a child with neurocutaneous melanosis associated with a Dandy-Walker complex. Magnetic resonance (MR) images showed shortened T1-weighted images in areas involving the amygdala, mesencephalon, rostral brain stem, and superior cerebellar surface compatible with melanin deposits. There was also partial agenesis of the cerebellar vermis with an enlarged fourth ventricle cyst along with a high-lying torcular and ventricular enlargement. Endoscopic fenestration and biopsy of the cyst wall was performed without evidence of abnormal melanin deposits in the meninges. OUTCOME: The patient eventually required ventriculoperitoneal shunting and at 1-year follow-up did not develop evidence of primary CNS melanoma. ILLUSTRATION: Computed tomography and MR images consistent with neurocutaneous melanosis and the Dandy-Walker complex are presented along with photographs of the cutaneous nevi. DISCUSSION: The major clinical and radiological features of this rare association, with only 11 previously reported cases, are discussed in detail.

Dandy-Walker Syndrome↗

Neurocutaneous melanosis associated with Dandy-Walker malformation.

Neurocutaneous melanosis is an uncommon congenital disorder consisting of benign or malignant melanocytic tumors of the leptomeninges with large or numerous cutaneous congenital melanocytic nevi. The Dandy-Walker malformation occurs as an enlarged posterior fossa with high insertion of the tentorium, hypoplasia or aplasia of the cerebellar vermis, and cystic dilatation of the fourth ventricle. To our knowledge, the association of these two conditions has been reported only 14 times. In this article, we present a newborn patient with neurocutaneous melanosis associated with Dandy-Walker malformation, which was diagnosed by magnetic resonance imaging.

Dandy-Walker Syndrome↗

Intraspinal melanotic arachnoid cyst and lipoma in neurocutaneous melanosis.

A 22-year-old woman with neurocutaneous melanosis is reported in whom an intraspinal melanotic congenital arachnoid cyst and melanotic lipoma occurred at the same thoracic location. Such combined occurrence of lesions of the central nervous system, producing compression of the spinal cord, has not been noted in any previously reported case of neurocutaneous melanosis. The pathogenesis of these two unusual melanotic lesions is discussed in relation to the ectomesenchymal properties of the neural crest. The concurrent melanotic arachnoid cyst and lipoma, in juxtaposition, were demonstrated by a computed tomography scan in which the preoperative diagnosis of lipoma was possible through the density of the lesion.

Adult↗

Benign melanosis and malignant melanoma of penis and male urethra.

Malignant melanoma of the penis and male uretha are unusually aggressive tumors which only rarely are cured by radical surgery. Melanosis of the penis may be confused with malignant melanoma, and we report a case of melanosis originally diagnosed and treated as melanoma with survival for twenty years. We contrast this with another case of malignant penile melanoma with a fatal outcome.

Adult↗

Generally recognized as safe (GRAS) evaluation of 4-hexylresorcinol for use as a processing aid for prevention of melanosis in shrimp.

4-Hexylresorcinol (C12H18O2) is proposed for use as a processing aid for prevention of melanosis ("black spot") in shrimp and as an alternative to the currently approved sulfites. A safety evaluation was conducted to affirm, based upon scientific procedures, the generally recognized as safe ("GRAS") status of 4-hexylresorcinol for proposed use. The GRAS safety evaluation compiled, reviewed, and analyzed data on the following areas: chemical identity, analytical methodology, historical and proposed uses, functionality, and safety. The publicly available safety data on 4-hexylresorcinol cover a broad range of potential toxicity concerns including acute and subacute toxicity, subchronic toxicity, carcinogenicity, mutagenicity, and allergenicity. These studies, along with the aforementioned data, demonstrate that 4-hexylresorcinol presents no risk of toxicity at the levels proposed for treatment of shrimp, and the use of 4-hexylresorcinol as a processing aid to prevent melanosis in shrimp is GRAS.

Animals↗

Neurocutaneous melanosis associated with Hirschsprung's disease in a male neonate.

Hirschsprung's disease is an inherited disorder characterized by the absence of ganglion cells in the distal bowel. Neurocutaneous melanosis is a rare congenital syndrome characterized by proliferation of melanin-producing cells in the skin and leptomeninges. The authors described a newborn patient with neurocutaneous melanosis associated with Hirschsprung's disease. This male baby had congenital hydrocephalus, large and multiple pigmented skin nevi, and severe abdominal distension. He showed marked hydrocephalus at birth and underwent a ventriculo-peritoneal shunt at the age of 5 days. Investigations for gut motility disorders revealed typical findings consistent with Hirschsprung's disease involving the rectosigmoid colon. He was surgically treated for Hirschsprung's disease after transanal endorectal pull-through at the age of 7 months. After settlement of the ventriculo-peritoneal shunt, the transanal approach was of significant value for keeping the intraperitoneal catheter clean. The association of developmental disorders of melanocytes and enteric ganglia, both of which originated from the neural crest, suggested the presence of mutual pathogenetic factors in the patient.

Anal Canal↗

Gastric triplication and peritoneal melanosis.

Duplications of the intestinal tract are rare malformations, and triplications are even less frequent; only two cases are found in the literature. Peritoneal melanosis, a diffuse, black pigmentation of the peritoneum is also rare; only six cases have been reported; five in young women and one in a 2-year-old girl. The authors report on a 6-month-old boy with a gastric triplication and peritoneal melanosis. The diagnostic criteria and the possible embryological origin are discussed.

Humans↗