Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0027960 (mole)
 21,279 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Carney complex, a familial multitumoral syndrome, comprises spotty skin pigmentation (lentigines and blue nevi), myxomas (heart, skin, and breast), endocrine tumors (adrenal cortex, pituitary, testis, and thyroid), and schwannomas. The skin pigmentary abnormality included two unusual conditions, epithelioid blue nevus and psammomatous melanotic schwannoma. The former tumor occurred on the extremities and trunk, less frequently on the head and neck; was multiple; and did not recur or metastasize. Clinically, it was pigmented, domed, and small (< 1 cm). Microscopically, it displayed two types of melanocytes--one intensely pigmented, globular, and fusiform and the other lightly pigmented, polygonal, and spindle. Nuclei of the latter cells were vesicular, with pale chromatin and single prominent nucleolus. None recurred or metastasized. The psammomatous melanotic schwannoma occurred in posterior spinal nerve roots, upper alimentary tract, bone, and skin. Microscopically, it was circumscribed but incompletely encapsulated and contained spindle and epithelioid cells, melanin, psammoma bodies, and fat. The spindle cells were arranged in interlacing fascicles, with whorling and occasional nuclear palisading. Twenty-one patients (68%) were alive without evidence of the neoplasm; two of these each had two local recurrences. Seven patients died, three (10%) as a result of metastasis.
 ...
PMID:Epithelioid blue nevus and psammomatous melanotic schwannoma: the unusual pigmented skin tumors of the Carney complex. 971 72

The clinicopathologic, immunocytochemical, and electron microscopic features of a case of meningeal melanocytoma arising in the phylum terminale are reported. Meningeal melanocytoma is an uncommon tumor that must be distinguished from metastatic or primary malignant melanoma, meningeal melanocytic nevi, pigmented meningioma, pigmented schwannoma or neurofibroma, and pigmented primitive neuroectodermal tumor. This is a difficult differential diagnosis that can be best archived by complementing histological examination with a selected panel of antibodies and, most important, electron microscopic study. The distinctive ultrastructural appearance of most of these lesions point to this technique as the gold standard in pigmented proliferations of the nervous system.
 ...
PMID:Meningeal melanocytoma: a case report and literature review. 980 60

Features of peripheral nerve sheath differentiation such as neuroid cords, nerve corpuscles, fascicle-like structures, and, exceptionally, palisading have been reported in melanocytic nevi. We report an intradermal melanocytic nevus with prominent Verocay-like bodies. The upper portion of the neoplasm was composed of typical round intradermal nevus cells, many of which were pigmented. Within the deeper portion, there was a nonpigmented spindle cell proliferation with prominent Verocay bodies, simulating a neurilemmoma. Typical nevus nests merged with neurilemmoma-like areas. The entire lesion stained positively for S-100 and Mart-1 proteins and negatively for HMB-45 stain. Diffuse Mart-1 positivity excluded a collision of a melanocytic lesion with a neurilemmoma. The histopathologic features of this nevus further support a close relation between nevus cells and Schwann cells.
 ...
PMID:Intradermal melanocytic nevus with prominent schwannian differentiation. 1180 80

Mutations at splice sites or surrounding sequences have been reported to cause aberrant splicing. However, splicing errors can also occur without sequence alterations. We investigated three tumor suppressor genes for aberrant splicing in tumors. At a low frequency per exon it was found in five of seven of the investigated in-frame exons of the neurofibromatosis type 1 (NF1) gene, in two of three exons of the neurofibromatosis type 2 (NF2) gene, and in one of three exons of the tuberous sclerosis 2 gene. It was detectable in all of the human tumor tissues tested (NF1 neurofibroma, sporadic intramedullar neurinoma, sporadic meningiomas, NF2 schwannoma, NF2 meningioma, basalioma, and naevus) as well as in cultured tumor cell lines and cultured primary cells. Hence, our data show that aberrant splicing is a very common process. According to simulations of the secondary structures of the pre-mRNA, we suggest that aberrant splicing is attributable to the rare occurrence of alternative structures at the splice donor site, which are not recognized by the splice machinery. In HeLa cells, aberrant splicing is found to be increased at elevated temperatures and low pH in vitro, conditions often found in tumor tissues. In three tumor tissues tested for one NF1 exon, we found approximately twice the amount of aberrant transcript as in normal tissues. Therefore, we suggest that the increase in aberrant splicing caused by environmental factors represents an additional mechanism for the reduction of the amount of tumor suppressor mRNA in the absence of relevant mutations in the tumor.
 ...
PMID:Aberrant splicing in several human tumors in the tumor suppressor genes neurofibromatosis type 1, neurofibromatosis type 2, and tuberous sclerosis 2. 1188 27

We present a case report of a classical presentation of palisaded encapsulated neuroma (PEN) of the skin occurring on the nasolabial crease and a review of the literature. A young woman presented with a smooth lobulated papule on the cheek enlarging over 2 years. Histologic examination revealed a well-circumscribed dermal nodule of small spindle cells with wavy nuclei arranged in fascicles, consistent with the diagnosis of PEN. PEN is a previously described, benign cutaneous neural tumour, with a histological appearance between that of a neurofibroma and a schwannoma. Though not uncommon, PEN remains under-diagnosed by many pathologists. Clinically, PEN is most commonly misdiagnosed as a basal cell carcinoma, a nevus, or as a neurofibroma.
 ...
PMID:Palisaded encapsulated neuroma--a classic presentation of a commonly misdiagnosed neural tumor. 1569 92

Congenital melanocytic naevus and neurofibromatosis type 1 are distinct clinical entities. A diagnosis of neurofibromatosis is difficult to make in the presence of a congenital melanocytic naevus because nodules may arise in the naevus that have similar histopathological appearances to neurofibromata. A case is reported where nodules arising from a naevus were examined histologically and were found to have neurofibroma and schwannoma like elements but strong positivity for S100 protein in keeping with dermal melanocytes. Lisch nodules were also said to be found in the patient but may represent nodular naevi of the irides. It is important that histopathological findings are interpreted within a clinical context and S100 protein immunohistochemical stain is valuable in helping to differentiate these two conditions.
 ...
PMID:Congenital melanocytic naevus with associated neurofibroma and schwannoma-like change. 1593 Sep 9

Tumors that originate from neural crest-derived cells represent a heterogeneous group of neoplasms including benign and malignant tumors with melanocytic and schwannian differentiation. The immunophenotype of these tumors is well known but little is known about the expression of smooth muscle/myofibroblastic markers in these tumors. A total of 590 neural crest-derived tumors (50 benign schwannomas, five malignant peripheral nerve sheath tumors, 80 neurofibromas, 240 nevocytic nevi, 115 primary melanomas, and 100 melanoma metastases) were studied with respect to alpha-smooth muscle actin and muscle-specific actin expression. alpha-Smooth muscle actin and muscle-specific actin-positive tumor cells with a co-expression of S-100 protein were found in one benign schwannoma, one primary cutaneous melanoma, and four melanoma metastases. Four of these cases were examined ultrastructurally, but typical actin filaments with focal densities were not found in any of the four. Other immunohistochemical markers examined including desmin, h-caldesmon and smooth muscle myosin heavy chain were negative in the tumor cells. The present results suggest that neural crest-derived tumors could show expression of alpha-smooth muscle actin on rare occasion.
 ...
PMID:Actin expression in neural crest cell-derived tumors including schwannomas, malignant peripheral nerve sheath tumors, neurofibromas and melanocytic tumors. 1915 61

A 36-year-old man developed a papular growth in a portion of a nevus sebaceus on the post-auricular scalp. Excision showed typical histologic changes of nevus sebaceus including epidermal papillomatosis with reduced numbers of hair follicles as well as numerous sebaceous glands high in the dermis that focally emptied directly to the overlying epidermis. Histologic sections of the papular growth at the superior pole of the nevus sebaceus showed a proliferation of cytologically bland basaloid epithelial tumor lobules both in the superficial dermis, with multiple connections to the epidermis, and within the deeper dermis in a nodular growth pattern demonstrating papillary mesenchymal bodies. Ductal structures with apocrine-type decapitation secretion were present. There was prominent palisading of nuclei in rows parallel to one another, alternating with bands of homogenous eosinophilic stromal material forming a ripple pattern resembling the Verocay bodies of schwannoma. The histologic features resembled those of rippled-pattern trichoblastoma with apocrine differentiation arising in a nevus sebaceus, an association not previously described. We discuss this case as well as review the literature on rippled-pattern trichoblastoma.
 ...
PMID:Rippled-pattern trichoblastoma with apocrine differentiation arising in a nevus sebaceus: report of a case and review of the literature. 1946 71

Melanotic schwannoma is a rare markedly pigmented peripheral nerve sheath tumor comprising cells with prominent melanization and schwannian features. The psammomatous variety is associated with Carney complex, a multiple neoplasia syndrome with spotty skin pigmentation. We present the first 2 reported cases of melanotic schwannoma arising in patients with a history of nevus of Ota, a rare dermal melanosis believed to represent a failure of melanocyte migration to the epidermis during embryogenesis. Case 1 involves a 40-year-old woman with a 1.8-cm, deeply pigmented, trigeminal nerve mass and pigmentation of the maxillary sinus mucosa and bone. Case 2 involves a 53-year-old woman with a 1.5-cm mass adjacent to the clavicle. Microscopically, both masses consist of partially encapsulated epithelioid and spindle cells with abundant melanin pigment, arising in association with peripheral nerves. Morphological, immunohistochemical, and ultrastructural features support a diagnosis of melanotic schwannoma. No psammoma bodies are noted, and neither patient exhibits any additional features of Carney complex. Melanotic schwannoma is most often benign but has been associated with malignant behavior in some cases. Distinguishing this nerve sheath tumor from malignant melanoma can be difficult but is of great clinical importance due to differences in prognosis and treatment.
 ...
PMID:Melanotic schwannoma arising in association with nevus of Ota: 2 cases suggesting a shared mechanism. 1978 55

The histological differential diagnosis between melanotic schwannoma, primary leptomeningeal melanocytic lesions and cellular blue nevus can be challenging. Correct diagnosis of melanotic schwannoma is important to select patients who need clinical evaluation for possible association with Carney complex. Recently, we described the presence of activating codon 209 mutations in the GNAQ gene in primary leptomeningeal melanocytic lesions. Identical codon 209 mutations have been described in blue nevi. The aims of the present study were to (1) perform a histological review of a series of lesions (initially) diagnosed as melanotic schwannoma and analyze them for GNAQ mutations, and (2) test the diagnostic value of GNAQ mutational analysis in the differential diagnosis with leptomeningeal melanocytic lesions. We retrieved 25 cases that were initially diagnosed as melanotic schwannoma. All cases were reviewed using established criteria and analyzed for GNAQ codon 209 mutations. After review, nine cases were classified as melanotic schwannoma. GNAQ mutations were absent in these nine cases. The remaining cases were reclassified as conventional schwannoma (n = 9), melanocytoma (n = 4), blue nevus (n = 1) and lesions that could not be classified with certainty as melanotic schwannoma or melanocytoma (n = 2). GNAQ codon 209 mutations were present in 3/4 melanocytomas and the blue nevus. Including results from our previous study in leptomeningeal melanocytic lesions, GNAQ mutations were highly specific (100%) for leptomeningeal melanocytic lesions compared to melanotic schwannoma (sensitivity 43%). We conclude that a detailed analysis of morphology combined with GNAQ mutational analysis can aid in the differential diagnosis of melanotic schwannoma with leptomeningeal melanocytic lesions.
 ...
PMID:Improved discrimination of melanotic schwannoma from melanocytic lesions by combined morphological and GNAQ mutational analysis. 2086 67


<< Previous 1 2 3 4 Next >>