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)

Blue naevi are reported for what is believed to be the first time in the capsule and fibrous trabeculae of lymph nodes. In one of the two cases that nodal blue naevus was accompanied by an ordinary blue naevus in the regional skin. These blue naevi are compared with the 'naevus-cell aggregates' in nodal capsule, the histogenesis of which is currently disputed. A developmental migratory arrest of melanocytes is thought to be the histogenetic mechanism involved in the production of these blue naevi in lymph nodes.
 ...
PMID:Blue naevi of lymph node capsule. 61 46

The sinu-atrial node in the heart of the mole, Mogera wogera, contains myocytes which are devoid of atrial specific granules and which may be classified into two types: electron-lucent (majority) and dark (minority). Numerous unmyelinated axon terminals, containing synaptic vesicles, face the nodal myocyte surface with interspaces of less than 300 nm. There are about 6 terminals per myocyte profile and about 10 per profile at nuclear levels. Of a total of 2717 of these terminals 85.2% are 50-200 nm from the nodal myocytes, and 9.6% form closer neuromuscular junctions, with less than 50 nm interspace and some membrane specialization. Such specilizations are almost exclusively found in relation to the dark, minority-type of nodal myocyte. Myelinated nerve fibers are also numerous within the mole SA node, and may terminate almost directly on a nodal myocyte. A few nerve fibers contain many mitochondria and may represent afferent endings. Nodal capillaries are smaller and fewer than capillaries in the juxtanodal myocardium, probably indicating a lesser blood supply to the SA node than to the ordinary myocardium.
 ...
PMID:The structure and innervation of the sinu-atrial node of the mole heart. 99 Dec 17

We examined 2,227 lymph nodes from 100 patients with clinical Stage I cutaneous melanoma for the presence of microscopic deposits of tumor. On examination of hematoxylin-and-eosin-stained sections, none had melanoma. Sixteen nodes from 14 patients had melanoma detectable by an antiserum to S-100 protein in a peroxidase-antiperoxidase (PAP) assay. The melanomatous nature of these cells was confirmed by their reaction with the melanoma-directed monoclonal antibody NKl/C3. The incidence of occult nodal metastases was highest in patients with deeply invasive and micrometrically thick primary tumors. The incidence of occult melanoma was not increased where additional serial sections were cut and semiserial sections examined. Pitfalls in the identification of occult melanoma cells (OMC) include S-100 protein-positive interdigitating dendritic cells, capsular nevus cells, a minority of sinus "macrophages," and the Schwann cells of node-associated nerves. Thus, we conclude that the incidence of early melanoma metastases in the regional lymph nodes of patients with clinical Stage I melanoma is greater than has previously been appreciated on the basis of assessment of routine hematoxylin-and-eosin-stained sections. Six of the 14 patients with OMC died of melanoma (41%), as compared to only 18 of 86 patients without OMC (21%; 0.10 greater than P greater than 0.05).
 ...
PMID:Occult tumor cells in the lymph nodes of patients with pathological stage I malignant melanoma. An immunohistological study. 271 94

The clinical and pathological features of 29 cellular blue nevi (CBN) and one malignant cellular blue nevus from our hospital files were reviewed. Although the sacrococcygeal region/buttock was the commonest single site, the majority of CBN occurred on the limb peripheries. Two-thirds of patients were under the age of 40 years. Follow-up of a mean of 7 years did not reveal any evidence of malignancy. Four histological subtypes were recognized: mixed biphasic, alveolar, fascicular or neuronevoid, and atypical varieties. One case developed a benign nodal metastasis. In one case, malignancy arose within a CBN. The importance of recognizing the variety of patterns, the benign behavior of the atypical variety, and the criteria for malignancy are herein discussed.
 ...
PMID:Benign and malignant cellular blue nevus. A clinicopathological study of 30 cases. 341 7

When malignant melanoma occurs in a lymph node, it is presumed to be metastatic, and the primary cutaneous/mucosal process is discovered to be either active, spontaneously regressed, previously excised, or occult. Nevus cell aggregates and nodal blue nevi are well-documented morphologic curiosities occurring in lymph nodes. It has been hypothesized that these nevus cell aggregates and blue nevi could be progenitors of lymph nodal malignant melanoma in patients without an obvious extranodal site of origin. We document a prototypical case of primary malignant melanoma evolving from precursor nevus cell aggregates associated with blue nevi in an axillary lymph node. The coexistence of nodal blue nevi and nevus cell aggregates implies a common origin from migratory neural crest cells arrested within mesenchyme.
 ...
PMID:Malignant melanoma primary in lymph node. The case of the missing link. 381 73

The immunohistochemical reactivity of the monoclonal antimelanoma antibody MEL-1 was evaluated on frozen sections of 9 malignant melanomas, 5 nevi, 1 squamous cell carcinoma, 1 basal cell carcinoma, 2 benign dermal fibrous histiocytomas, 1 infiltrating ductal and 2 infiltrating lobular carcinomas of the breast, 1 primary squamous cell carcinoma and 1 adenocarcinoma of the lung, 1 lung metastasis of gastric adenocarcinoma, 1 adenocarcinoma of the large bowel, 1 lymph node, 1 case of malignant histiocytosis and one of lymph nodal immunoblastic lymphoma, and 1 biopsy of oral cavity mucosa. In primary and metastatic malignant melanoma, junctional nevi, and the upper half of compound and dermal nevi, the staining was intense. Also, benign dermal fibrous histiocytoma and the case of lymph nodal malignant histiocytosis showed an intense reactivity, whereas the immunostaining positivity of the squamous cell carcinoma of the skin, the lung adenocarcinoma, the squamous cutaneous and mucosal epithelium, and the sweat and sebaceous glands was slight. In ductal and lobular infiltrating carcinoma of the breast only focal areas or isolated tumor cells were positive. The lack of reactivity of deep dermal melanocytes of compound and dermal nevi may be correlated with a different antigenic phenotype of the melanocytes. After discussion of the technical problems, the application of MEL-1 was suggested, for diagnostic purpose, to identify lymph nodal metastases in cases of primary self regressed malignant melanoma and to detect lymph nodal metastatic microfoci of malignant melanoma.
 ...
PMID:Immunohistochemical reactivity of the antimelanoma monoclonal antibody MEL-1. 389 83

From 1977 to 1983, 44 cases with nevus cells in the capsule and trabeculae of axillary lymph node specimens from about 7000 mastectomies performed for primary breast cancer were found. This finding was therefore less than 1%. In 3 cases, the nevus cells were present in 2 nodes, whereas in 41 cases solitary nodes were involved. In 13 cases, nevus cells were present in nodes that also contained metastatic carcinoma. Silver impregnation of reticulin fibers is very useful for the differential diagnosis of nodal metastases of breast carcinoma.
 ...
PMID:Nevus cells in axillary lymph nodes from radical mastectomy specimens. 402 39

1. The experiments were done on single Ranvier nodes of Xenopus laevis (voltage clamp) and Rana esculenta (action potentials). Rate and size of the effect of tetrodotoxin were determined by the reversible reduction of either the sodium inward current (Xenopus) or of V(A), the maximum rate of rise of the action potential (Rana).2. The results of tetrodotoxin block at equilibrium could be excellently fitted by assuming a one-to-one reaction between toxin molecules and sodium channels of the Xenopus membrane with an equilibrium dissociation constant K = 3.60 nM at room temperature. V(A) was not linearly related to the fraction of unblocked sodium channels and 10.9 nM tetrodotoxin was necessary on the average to reduce V(A) to 50% in Rana motor fibres; in sensory fibres a lower concentration sufficed.3. Onset and offset of the tetrodotoxin effect on Xenopus nodes could be quantitatively interpreted as being determined by the rates of the tetrodotoxin channel reaction. Experiments with 3.1 and 15.5 nM tetrodotoxin at room temperature yielded an association rate constant, k(1), of 2.94 x 10(6)M(-1) sec(-1) and a dissociation rate constant, k(2), of 1.42 x 10(-2) sec(-1). In these experiments the equilibrium dissociation constant, K, was 3.31 nM. If determined solely from the onset in the two tetrodotoxin concentrations, k(1) = 3.25 x 10(6)M(-1) sec(-1) and K = k(2)/k(1) = 4.08 nM was calculated.4. In Rana fibres the onset and offset of V(A) reduction by 15.5 and 31 nM tetrodotoxin was evaluated using the equilibrium effects of intermediary tetrodotoxin concentrations for calibration. The average results at room temperature were k(1) = 4 x 10(6)M(-1) sec(-1), k(2) = 1.4 x 10(-2) sec(-1) and K = 3.4 nM.5. The very short latency with which V(A) started to decline when tetrodotoxin was suddenly applied proved that the toxin had ready access to the membrane.6. The temperature dependence of k(1), k(2) and K in the Xenopus experiments could be described by Arrhenius plots yielding activation energies, E(a), of 9.8, 20.5 and 7.0 kcal/mole, respectively, corresponding to Q(10) values of 1.82, 3.42 and 1.53 (between 12 and 22 degrees C). For k(1), determined from onset alone, E(a) = 13.7 kcal/mole (Q(10) = 2.25) was obtained. Although in Rana the temperature dependence of the rate constants could not be determined directly, the Q(10) for k(2) must have been of the order of 3.7. The results suggest that the rate of the toxin action on the nodal membrane of Xenopus and Rana is limited by the tetrodotoxin-sodium site reaction.
 ...
PMID:The rate of action of tetrodotoxin on myelinated nerve fibres of Xenopus laevis and Rana esculenta. 454 28

Three cases of blue nevi associated within lymph nodes were identified. These nodal blue nevi were all incidentally discovered in relation to axillary lymph nodes removed as part of modified radical mastectomy procedures for carcinoma of the breast. Only one lymph node from each axillary dissection contained the lesion. In one case, gross examination revealed black streaks in the capsule of the lymph node, providing the first reported macroscopic illustration of the blue nevus within the capsule of a lymph node. The lesions each occupied small portions of the lymph node capsules, with penetration into perinodal fibroadipose tissue in two cases and extension along intranodal fibrous trabeculae in the third case. Histologically, heavily pigmented dendritic and bipolar nevus cells were admixed with melanophages. Ultrastructural examination of one case documented the presence of mature melanosomes and possible basement membrane material. None of the patients had notable skin lesions and all were free of disease at last follow-up. Nodal blue nevi are probably an unusual variant of the nevus aggregate associated with lymph nodes. These lesions limited to the nodal capsule and supporting stroma should not be mistaken for malignant melanoma.
 ...
PMID:Nodal blue nevi. A study of three cases. 609 30

The Merkel cell is a distinctive nondendritic, nonkeratinocytic, epithelial clear cell believed to migrate from the neural crest to the epidermis and dermis, which is usually located in or near the basal layer of the epidermis and associated with nerve terminations. Merkel first described these cells in 1875 as "Tastzellen" occurring in the snout of a mole. They are believed to function as slowly adapting mechanoreceptors that mediate the sense of touch. Tumors arising from Merkel cells have been reported to occur on the head and neck area, the trunk, arms, and legs, and resemble a primary cutaneous lymphoma or cutaneous metastasis of a lymphoma or a carcinoma. Electron microscopy, to locate the characteristic membrane-bound, dense core neurosecretory granules, is needed for accurate diagnosis. These tumors must be treated aggressively to minimize the chance of local recurrence and nodal or visceral metastases. The authors present a case of Merkel cell tumor occurring on the eyelid. The clinical history, light and electron microscopic findings are shown.
 ...
PMID:A Merkel cell tumor of the eyelid. 667 39


1 2 3 4 5 6 7 8 Next >>