Genotoxic Stress Abrogates Renewal of Melanocyte Stem Cells by Triggering Their Differentiation
Synopses of papers 57A - Amazon S3...features, and mitotic figurell0 HPF. The presence of melanocyte...
Transcript of Synopses of papers 57A - Amazon S3...features, and mitotic figurell0 HPF. The presence of melanocyte...
Synopses of papers 57A
MELANOCYTES IN EPITHELIAL NEST: A DIAGNOSTIC CLUE FOR TRICHOEPITHELIOMAS~TRICHOBLASTOMAS
2. Aly,' R. Cerio,'*' L. Pozo,' and S.J. Diaz-Cane.',' 'Barts and The London NHS Trust, and 'Barts and The London School of Medicine and Dentistry (London, UK)
Introduction: Epithelial pilar neoplasms are relatively fare and heterogeneous, revealing pigment exceptionally. The presence of melanocytes has not been studied and there is no systematic evaluation of histologic features, resulting in a low diagnostic reproducibility. Methods: We selected trichoepithelioma/trichoblastoma (46) with appropriate archival material. We systematically evaluated growth pattern (multifocal or not), type of squamous differentiation, cytological evidence of catagen, presence of dual cell population, epithelial and stromal pigment, epithelial and stromal calcification, stromal reaction (myxoid, lamellar fibrosis, hyalinization), nuclear features, and mitotic figurell0 HPF. The presence of melanocyte was investigated by immunohistochemistry (SIOO, HMB-45). Results: All cases revealed a dual population, epithelial cells revealing bland nuclei and distinct nucleolus and interstitial cells in the nests showing hyperchromatic spindle nuclei, The latter were revealed S-I 00- and HMB-45-positive. Epithelial pigment also correlated with catagen cytological features (71 %). Tumors revealing multifocal growth pattern showed mitotic figures (80%), while these were less frequently present in non-multifocal neoplasms (49%). The other histological variables revealed no correlation. Conclusions: Melanocyte colonization is a very common finding in trichoepitheliomasltrichoblastomas and can help identifying these neoplasms. Multifocal growth pattern should be investigated especially in mitotically active neoplasms, for which a complete excision is more difficult.
Immunohistochemical expression of L-type amino acid transporter l(LAT1) for human breast cancer
Uchirrasaki. S. and Sakamoto, A.
Department of Pathology, Kyorin University School of Medicine, Tokyo
Background: L-type amino acid transporter I(LAT1) is one of the novel drug transporters of cell membrane (Kanai: J Biol Chem 273, 23629, 1998). In vitro, growth of sarcoma cells was inhibited by LATl antagonist, and malignant cells tended to immunohistochemical reactivity for anti-LAT1 monoclonal antibody. In this study, we examined irnmunohistochemical expression for LATl using human breast cancer tissues.
Materials and Methods: We used 20 cases of histologically confirmed breast cancer tissues. Immunohistochemical study was done by anti- LATl monoclonal antibody. Evaluation was given by 3 categories, namely, strongly positive, weakly positive and negative.
Results and Discussion: Positive immunoreactivity was found only in the cytoplasm of cancer cells. Non-cancerous cells surrounding the tumor were generally negative, but weakly positive, in part. As to cancer cells, 15 and 4 cases (75% and 20%) revealed strongly positive and weakly positive, respectively. One case showed negative (5%). More than 90% of cancer cases showed immunohistochemical reactivity. Therefore, our data suggest that LATl can be a candidate for a useful tumor marker. We believe that LATl immunoreactivity can be applied for histodiagnosis of the tumors as a meaningful tool.
A retrospsctive studylaudit of malignant melanoma re-excision specimens.
SK Suvama', RW Grifflth$ Depts Histopatholopy', Plastic Surge#, Northern General Hospital, Sheffield S5 7AU, UK
This study looked at the re-excision of 103 cases of previously diagnosed mallgnant melanoma, from this centre between 1997 and 2000. Mwoxopic data was collected on the length, breadth and wldth of the specimens and the dimensions of the scar. The number of blocks taken and the presence of residual melanoma in the re-excision specimen was recorded. The sampllng of the re-exdsion specimens was not Influenced by the dlnical data received, and varied according to individual pathologists and the specimen size. The number of blocks taken ranged from 1 to 25 (mean 4.1). 2 cases contained residual fod of melanoma, present In 5/6 blocks and 3/3 b4cks respecbivety. Reappraisal of the original spedmens showed the original melanomas to be incompletely excised. These flndings support previous work that suggested 1 block per reexdsion biopsy of fully excised melanomas would suffice for clearance conflmon. However, any sample with melanoma at peripheral boundaries of exdsion may require mote than 1 block, and possibly the entlre specimen to be examined, in order to identify residual tumour.
JSP Guidelines for the use of human pathology specimens in research and education --- Conteuts, process of enactment, and the remaining problems
Shieeo Mori, M.D. Professor, Division of Pathology, Institute of Medical Science, University of Tokyo (President of the Japanese Society of Pathology, JSP)
The Japanese Society of Pathology (JSP) recently enacted two
guidelines for the use of human pathology specimens in medical research and education. Those guidelines are primarily for pathologists who are now facing at their laboratories with ethical problems. One of such recent problems is the enactment of a guideline, by the Japanese Ministries for genetic researches in which rather strict conditions are imposed to protect the right of patients. The second is from recent lawsuits where the right of patients is claimed on pathology specimens that were used for education and even in diagnosis. Our guidelines are simple and enough short, referring to the right of patients, informed consents, preservation of specimens, stressing the need to obtain public consensus and supports on pathology. It is my wish to exchange information and experiences of this field with members of the Society of Pathologists at Great Britain and Ireland.
TE-TBL - Melanocyte Colonization 29/11/2012
1
Melanocytes in epithelial nests: A diagnostic clue for trichoepitheliomas / trichoblastomas
Z Aly, R Cerio, L Pozo, SJ Diaz-Cano The Journal of Pathology. 01/2002; 198:57A.
DOI: 10.6084/m9.figshare.97898
Benign Pilar Neoplasms n Relatively rare tumors n Histologically heterogeneous group of
neoplasms n Pigmented variants are reported
exceptionally n No systematic study evaluates
histological features and melanocyte presence
TE-TBL - Melanocyte Colonization 29/11/2012
2
Benign Pilar Neoplasms
n Histological features
n Connections with
superficial epidermis
n Catagen
n Small nucleolus
n Melanin
Benign Pilar Neoplasms
n Histological features
n Connections with
superficial epidermis
n Catagen
n Small nucleolus
n Melanin
TE-TBL - Melanocyte Colonization 29/11/2012
3
Benign Pilar Neoplasms. Methods n Case selection: 46 trichoepitheliomas-
trichoblastomas n Systematic histological evaluation n Immunohistochemistry for S-100,
HMB-45, Ki-67, mcm-2, c-kit, and CD34 by topographic compartments
n Statistical analyses by growth pattern, presence of melanin, and topographic compartments
Pilar Differentiation: c-kit
TE-TBL - Melanocyte Colonization 29/11/2012
4
Pilar Differentiation: CD34
Dendritic Cells in Pilar Neoplasms
S-100
TE-TBL - Melanocyte Colonization 29/11/2012
5
Dendritic Cells in Pilar Neoplasms
HMB-45 CD1a
Melanocytes and Proliferation
HMB-45/Ki-67
TE-TBL - Melanocyte Colonization 29/11/2012
6
Epidermal Connections in Benign Pilar Neoplasms
05
1015202530354045
Ki-67 Sup CD34 Sup CD34 Deep S-100 Deep
Multifocal Focal No Connection
Catagen in Benign Pilar Neoplasms
02468
101214
c-kit Deep CD34 Deep S-100 Sup
No Catagen Catagen
TE-TBL - Melanocyte Colonization 29/11/2012
7
Calcifications in Benign Pilar Neoplasms
05
1015202530354045
MF/100 HPF* c-kit Deep CD34 Deep
No Calcifications Calcifications
Melanin in Benign Pilar Neoplasms
02468
101214
Ki-67 Deep* MCM-2 Deep* c-kit Deep
No Melanin Melanin
TE-TBL - Melanocyte Colonization 29/11/2012
8
Benign Pilar Neoplasms. Conclusions I n Melanocyte colonization is a very
common finding in trichoepitheliomas-trichoblastomas and can help identifying these neoplasms.
n Multifocal growth pattern should be investigated especially in mitotically active neoplasms, for which a complete excision is more difficult.
Benign Pilar Neoplasms. Conclusions II n The deep tumor compartment drives the
expression of pilar markers (c-kit, CD34) and histological differentiation features (catagen, calcifications). CD34 and c-kit suggest proliferating pilar differentiation
n The proliferative compartment of benign pilar neoplasms is superficial (bulge equivalent)