scholarly journals A case of amelanotic melanoma in the maxillary gingiva

2021 ◽  
Vol 33 (2) ◽  
pp. 61-68
Author(s):  
Keisuke Mori ◽  
Syuhei Iwamoto ◽  
Asana Kamohara ◽  
Reona Aijima ◽  
Atsushi Danjo ◽  
...  
Keyword(s):  
Amelanotic Melanoma

Diagnostic Value of Electron Microscopy in Soft Tissue Tumors

1970 ◽  
Vol 28 ◽  
pp. 220-221
Author(s):  
Gerald Fine ◽  
Azorides R. Morales
Keyword(s):  
Cardiac Myxoma ◽  
Osteogenic Sarcoma ◽  
Diagnostic Value ◽  
Soft Tissue Tumors ◽  
Amelanotic Melanoma ◽  
Growth Patterns ◽  
Light Microscopic Level ◽  
Mesenchymal Tumors ◽  
Good Agreement

For years the separation of carcinoma and sarcoma and the subclassification of sarcomas has been based on the appearance of the tumor cells and their microscopic growth pattern and information derived from certain histochemical and special stains. Although this method of study has produced good agreement among pathologists in the separation of carcinoma from sarcoma, it has given less uniform results in the subclassification of sarcomas. There remain examples of neoplasms of different histogenesis, the classification of which is questionable because of similar cytologic and growth patterns at the light microscopic level; i.e. amelanotic melanoma versus carcinoma and occasionally sarcoma, sarcomas with an epithelial pattern of growth simulating carcinoma, histologically similar mesenchymal tumors of different histogenesis (histiocytoma versus rhabdomyosarcoma, lytic osteogenic sarcoma versus rhabdomyosarcoma), and myxomatous mesenchymal tumors of diverse histogenesis (myxoid rhabdo and liposarcomas, cardiac myxoma, myxoid neurofibroma, etc.)

Ultrastructural observations on the in vitro cytoadherence of Plasmodium falciparum infected red blood cells

1990 ◽  
Vol 48 (3) ◽  
pp. 914-915
Author(s):  
D.J.P. Ferguson ◽  
A.R. Berendt ◽  
J. Tansey ◽  
K. Marsh ◽  
C.I. Newbold
Keyword(s):  
Plasmodium Falciparum ◽  
Red Blood Cells ◽  
Blood Cells ◽  
Umbilical Vein ◽  
Cell Types ◽  
Amelanotic Melanoma ◽  
Cytoplasmic Process ◽  
Umbilical Vein Endothelial Cells

In human malaria, the most serious clinical manifestation is cerebral malaria (CM) due to infection with Plasmodium falciparum. The pathology of CM is thought to relate to the fact that red blood cells containing mature forms of the parasite (PRBC) cytoadhere or sequester to post capillary venules of various tissues including the brain. This in vivo phenomenon has been studied in vitro by examining the cytoadherence of PRBCs to various cell types and purified proteins. To date, three Ijiost receptor molecules have been identified; CD36, ICAM-1 and thrombospondin. The specific changes in the PRBC membrane which mediate cytoadherence are less well understood, but they include the sub-membranous deposition of electron-dense material resulting in surface deformations called knobs. Knobs were thought to be essential for cytoadherence, lput recent work has shown that certain knob-negative (K-) lines can cytoadhere. In the present study, we have used electron microscopy to re-examine the interactions between K+ PRBCs and both C32 amelanotic melanoma cells and human umbilical vein endothelial cells (HUVEC).We confirm previous data demonstrating that C32 cells possess numerous microvilli which adhere to the PRBC, mainly via the knobs (Fig. 1). In contrast, the HUVEC were relatively smooth and the PRBCs appeared partially flattened onto the cell surface (Fig. 2). Furthermore, many of the PRBCs exhibited an invagination of the limiting membrane in the attachment zone, often containing a cytoplasmic process from the endothelial cell (Fig. 2).

Primary Amelanotic Melanoma of the Palm

1980 ◽  
Vol 42 (5) ◽  
pp. 791-795 ◽  
Author(s):  
Kayoko MATSUNAGA ◽  
Katsuhiko SAKAI ◽  
Mitsuyoshi HIRAMATSU ◽  
Kisaku YAZAKI ◽  
Hiroshi UEDA
Keyword(s):  
Amelanotic Melanoma

Large Amelanotic Melanoma and Vitiligo

2009 ◽  
Vol 145 (10) ◽  
Author(s):  
Eli Andrew Silver ◽  
Adam E. Hofmann ◽  
David Williams ◽  
Herbert Srolovitz ◽  
Youssef Tahiri ◽  
...  
Keyword(s):  
Amelanotic Melanoma

scholarly journals Cerebellar amelanotic melanoma can mimic cerebellar abscess in a pediatric case of neurocutaneous melanosis

2021 ◽  
Author(s):  
Enricomaria Mormina ◽  
Sergio Lucio Vinci ◽  
Alessandra Coglitore ◽  
Carmela Visalli ◽  
Agostino Tessitore ◽  
...  
Keyword(s):  
Amelanotic Melanoma ◽  
Pediatric Case ◽  
Neurocutaneous Melanosis ◽  
Cerebellar Abscess

scholarly journals In Vitro Anticancer Potential of Jasione montana and Its Main Components Against Human Amelanotic Melanoma Cells

2021 ◽  
Vol 22 (7) ◽  
pp. 3345
Author(s):  
Aleksandra Maria Juszczak ◽  
Robert Czarnomysy ◽  
Jakub Władysław Strawa ◽  
Marijana Zovko Končić ◽  
Krzysztof Bielawski ◽  
...  
Keyword(s):  
Cell Line ◽  
Melanoma Cell ◽  
Melanoma Cell Line ◽  
Binding Assay ◽  
Annexin V ◽  
Melanoma Cells ◽  
Amelanotic Melanoma ◽  
Cytotoxic Activities ◽  
Ionization Mass ◽  
Caspase 9

Jasione montana L. (Campanulaceae) is used in traditional Belarusian herbal medicine for sleep disorders in children, but the chemical composition and biological activity have not been investigated. In this study, the activities of J. montana extracts, their fractions and main compounds were evaluated in amelanotic melanoma C32 (CRL-1585) cells and normal fibroblasts (PCS-201-012). The extracts and fractions were analyzed using liquid chromatography–photodiode array detection–electrospray ionization–mass spectrometry (LC–PDA–ESI–MS/TOF) to characterize 25 compounds. Further, three major and known constituents, luteolin (22) and its derivatives such as 7-O-glucoside (12) and 7-O-sambubioside (9) were isolated and identified. The cytotoxic activities against fibroblasts and the amelanotic melanoma cell line were determined using the fixable viability stain (FVS) assay. The influence of diethyl ether (Et2O) fraction (JM4) and 22 on apoptosis induction was investigated using an annexin V binding assay. The obtained results showed significant cytotoxicity of JM4 and 22 with IC50 values of 119.7 ± 3.2 and 95.1 ± 7.2 μg/mL, respectively. The proapoptotic potential after 22 treatment in the C32 human amelanotic melanoma cell line was comparable to that of vinblastine sulfate (VLB), detecting 29.2 ± 3.0% apoptotic cells. Moreover, 22 displayed less necrotic potential against melanoma cells than VLB. In addition, the influences of JM4 and 22 on the dysfunction of the mitochondrial membrane potential (MMP), cell cycle and activity of caspases 3, 8, 9, and 10 were established. The effects of JM4 on MMP change (74.5 ± 3.0% of the cells showed a reduced MMP) corresponded to the results obtained from the annexin V binding assay and activation of caspase-9. JM4 and 22 displayed a significant impact on caspase-9 (40.9 ± 2.4% of the cells contained active caspase-9 after JM4 treatment and 16.6 ± 0.8% after incubation with 22) and the intrinsic (mitochondrial) apoptotic pathway. Moreover, studies have shown that JM4 and 22 affect the activation of external apoptosis pathways by inducing the caspase-8 and caspase-10 cascades. Thus, activation of caspase-3 and DNA damage via external and internal apoptotic pathways were observed after treatment with JM4 and 22. The obtained results suggest that J. montana extracts could be developed as new topical preparations with potential anticancer properties due to their promising cytotoxic and proapoptotic potential.

scholarly journals Ulcerated amelanotic melanoma of the ear in an 11 year old with Fitzpatrick VI skin type: A case report

2021 ◽  
Author(s):  
Matthew Roberts ◽  
J. Paul Moxham ◽  
Allison Gregory ◽  
Linlea Armstrong ◽  
Jefferson Terry ◽  
...  
Keyword(s):  
Case Report ◽  
Type A ◽  
Amelanotic Melanoma ◽  
Skin Type

Progressive Appearance of Pigmentation in Amelanotic Melanoma Lesions

2002 ◽  
Vol 15 (4) ◽  
pp. 282-289 ◽  
Author(s):  
Karine A. Cohen-Solal ◽  
Steven M. Crespo-Carbone ◽  
Jin Namkoong ◽  
Kerine R. Mackason ◽  
Kathleen G. Roberts ◽  
...  
Keyword(s):  
Amelanotic Melanoma

Palpebral Amelanotic Melanomas in F344 Rats

1993 ◽  
Vol 30 (3) ◽  
pp. 280-286 ◽  
Author(s):  
K. Yoshitomi ◽  
G. A. Boorman
Keyword(s):  
Tumor Cells ◽  
Electron Microscopic Examination ◽  
Ultrastructural Feature ◽  
Amelanotic Melanoma ◽  
Electron Microscopic ◽  
Cell Processes ◽  
Poorly Differentiated ◽  
The Right ◽  
F344 Rats ◽  
Left Eyelid

Spontaneous amelanotic melanomas in the eyelids of F344 rats were found in one of 1/926 (0.11 %) male and 5/925 (0.54%) female F344 rats that were used as control and treated animals in five different carcinogenicity studies conducted by the National Toxicology Program (Research Triangle Park, NC). These melanomas were grossly recognized as single, tan or white, well-circumscribed masses of the right or left eyelid. These melanomas primarily occurred in the dermis of the skin of the eyelids and consisted of poorly differentiated spindle cells characteristically arranged in interlacing fascicles. Rarely, epithelioid tumor cells were also observed, and these tumor cells showed a negative histochemical reaction for melanin. The epidermis and dermal–epidermal junction were usually uninvolved. The diagnosis of amelanotic melanoma could only be established by electron microscopic examination. The most striking ultrastructural feature of the tumor cells was a large number of intracytoplasmic premelanosomes (stage II melanosomes without melanin), which nearly filled the cytoplasm of most tumor cells. Giant premelanosomes and melanophagosomes were also seen. The tumor cells did not possess the ultrastructural features characteristic of Schwann cells (thin, long cell processes and pericytoplasmic basal laminae). The histologic and ultrastructural features of these palpebral tumors were similar to those of cutaneous amelanotic melanomas of the pinna in F344 rats.

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