acid-phosphatase and Nevus--Pigmented

A histochemical study of alpha-D-mannosidase revealed that normal human melanocytes (resting state, activated, lentigo simplex) exhibit either no or just detectable activity, as do melanocytes in the initial phase of lentigo maligna. Junctional, or occasionally zone A naevocytes displayed a very low enzyme activity. On the other hand, melanocytes in the initial stage of neoplastic transformation (dysplastic naevi, advanced stage of lentigo maligna) and also melanoma cells in disorders of low malignant potential (initial naevogenic melanoma, superficial spreading melanoma) displayed a high activity uniformly throughout the cell population. In the malignant forms (nodular melanoma, recurrences, metastases), the enzyme activity was remarkably heterogeneous, suggesting a breakdown of uniformity during malignant transformation. The significance of alpha-mannosidase activity induction in the course of melanocyte neoplastic transformation is not clear at present. The results of biochemical assays suggest that the lysosomal isoenzyme is mainly responsible. Other lysosomal enzymes, and dehydrogenases studied concomitantly, did not display any comparable phenomena of induction or similar behaviour. However, the results of a comparison of alpha-mannosidase with the melanocyte reference enzyme tyrosinase suggested activity patterns in the enzyme pair which may provide a better insight into the biochemical differentiation of human melanocytes in neoplastic disorders. The possible relationship of alpha-mannosidase to melanogenesis is also discussed.

Topics: Acid Phosphatase; Alkaline Phosphatase; alpha-Mannosidase; Carboxylesterase; Carboxylic Ester Hydrolases; Glucuronidase; Histocytochemistry; Humans; Mannosidases; Melanoma; Monophenol Monooxygenase; Nevus, Pigmented; Oxidoreductases; Skin Neoplasms

The melanin macroglobule (MMG), formerly called "macromelanosome," is a cytoplasmic spherical granule formed in the melanocyte, varying in size from one to several microns, much larger than normal ellipsoidal melanosomes. Although ultrastructural features of MMG have been adequately described in the past, there has been a disagreement about the formation process of MMG. In order to further elucidate the nature and origin of MMG, electron microscopic studies were conducted in several pigmentary disorders. Our findings included: (1) The most remarkable characteristics of MMG are (a) the pleomorphism of their internal structure and (b) the variation of their size. (2) MMG do not represent true melanosomes but unique forms of autolysosomes resulting from the fusion of autophagosomes (containing various numbers of melanosomes) with primary and/or secondary lysosomes. (3) MMG are retained within melanocytes or transferred to keratinocytes and to Langerhans cells in the epidermis, and to macrophages in the dermis in any of their developmental stages. After transfer, MMG can fuse with other heterolysosomes and probably increase in size in these cells. We regard melanosome complexes as but one step in an autophagic process within melanocytes which can, on occasion, produce MMG as residual bodies.

Topics: Acid Phosphatase; Albinism; Autophagy; Biopsy; Eye Diseases; Histocytochemistry; Humans; Melanocytes; Microscopy, Electron; Microscopy, Electron, Scanning; Monophenol Monooxygenase; Neurofibromatosis 1; Nevus, Pigmented; Skin Neoplasms; Terminology as Topic

Junctional nevi of the oral mucosa are rare and may be precancerous. A patient who had an enlarging junctional nevus of the labial mucosa with an adjacent lentigo simplex was studied by light and electron microscopy. On the basis of morphologic similarities--dentritic appearance, lack of desmonsomes, proliferative melanin production, and lack of cytoplasmic fibrils--it appears that the nevus cell most likely develops from melanocytes. The reason for the transformation from melanocyte to nevus cell or junctional nevus cell hyperplasia is unknown.

Topics: Acid Phosphatase; Aged; Basement Membrane; Biopsy; Cytoplasm; Female; Humans; Lip Neoplasms; Lysosomes; Macrophages; Melanins; Melanocytes; Mitochondria; Monophenol Monooxygenase; Mouth Mucosa; Nevus, Pigmented; Ribosomes; Vacuoles

By means of histochemical methods (gel-film incubation-media) superficial spreading melanoma, nodular melanoma and lentigo maligna melanoma are investigated. The result of this examination is that with regard to their enzyme spectra, the nodular melanoma and the nodular part of the superficial spreading melanoma are very similar. Glucose-6-phosphate dehydrogenase shows the strongest enzyme reaction, followed by succinate dehydrogenase and lactate dehydrogenase. The beta-hydroxybutyrate dehydrogenase reaction is always weak. The reaction of acid phosphatase is between negative and weakly positive. Significant differences, however, are observed in lentigo maligna and in lentigo maligna melanoma. In both, the strongest formazan deposits are seen with succinate dehydrogenase, sometimes also with lactate dehydrogenase. The glucose-6-phosphate dehydrogenase reaction, however, is sometimes considerably weaker. In the case of lentigo maligna melanoma, the activity of beta-hydroxybutyrate dehydrogenase often is increased, and acid phosphatase also shows higher reactions than in the other melanomas. These differences in the enzyme pattern correspond to the different biological behavior of the tumours. The enzymatical and biological characteristics of lentigo maligna melanoma possibly derive more from the characteristics of the tumour itself which are not dependent on the area.

Topics: Acid Phosphatase; Esterases; Formazans; Glucosephosphate Dehydrogenase; Humans; Hydroxybutyrate Dehydrogenase; L-Lactate Dehydrogenase; Melanoma; Monophenol Monooxygenase; Nevus, Pigmented; Skin; Succinate Dehydrogenase

Topics: Acid Phosphatase; Biopsy; Catechol Oxidase; Cytoplasmic Granules; Histocytochemistry; Humans; Mast Cells; Melanins; Melanocytes; Microscopy, Electron; Monophenol Monooxygenase; Nevus, Pigmented; Organoids; Phagocytes; Skin

Topics: Acid Phosphatase; Clinical Enzyme Tests; Glucosephosphate Dehydrogenase; Histocytochemistry; Humans; Hydroxybutyrate Dehydrogenase; L-Lactate Dehydrogenase; Methods; Microscopy, Fluorescence; Monophenol Monooxygenase; Nevus, Pigmented; Skin Neoplasms; Succinate Dehydrogenase

Topics: Acid Phosphatase; Adult; Catechol Oxidase; Histocytochemistry; Humans; Inclusion Bodies; Melanins; Melanocytes; Microscopy, Electron; Models, Biological; Morphogenesis; Nevus, Pigmented; Organoids; Skin; Skin Neoplasms

Topics: Acid Phosphatase; Animals; Catechol Oxidase; Endoplasmic Reticulum; Golgi Apparatus; Guinea Pigs; Histocytochemistry; Humans; Melanins; Melanocytes; Microscopy, Electron; Nevus, Pigmented; Peroxidases; Ultraviolet Rays

Topics: Acid Phosphatase; Adolescent; Autoradiography; Cytoplasm; Electron Transport Complex IV; Esterases; Female; Glucosephosphate Dehydrogenase; Glyceraldehyde-3-Phosphate Dehydrogenases; Glycerolphosphate Dehydrogenase; Histocytochemistry; Humans; Hyalin; Hypertrophy; Ichthyosis; Isocitrate Dehydrogenase; Keratosis; L-Lactate Dehydrogenase; Leucyl Aminopeptidase; Microscopy, Electron; Nevus, Pigmented; Skin; Skin Diseases; Staining and Labeling; Succinate Dehydrogenase; Tritium; Uridine

Topics: Acid Phosphatase; Animals; Autoradiography; Dogs; Dopa Decarboxylase; Humans; Mast Cells; Mast-Cell Sarcoma; Melanins; Mice; Microscopy, Electron; Nevus, Pigmented; Oxidoreductases; Peritoneum; Peroxidases; Rats; Skin; Skin Neoplasms; Urticaria Pigmentosa

Topics: Acid Phosphatase; Dihydroxyphenylalanine; Histocytochemistry; Humans; In Vitro Techniques; Melanins; Melanoma; Microscopy, Electron; Nevus, Pigmented; Phagocytosis; Skin; Tyrosine Decarboxylase

Topics: Acid Phosphatase; Alkaline Phosphatase; Cholinesterases; Humans; In Vitro Techniques; Leucyl Aminopeptidase; Melanoma; Monoamine Oxidase; Nevus, Pigmented; Succinate Dehydrogenase; Tyrosine Decarboxylase