Atypical umbilical naevi: histopathological analysis of 20 cases

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/110566/1/his12503.pd

Dermal squamo‐melanocytic tumour: metastasizing or not?

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/86863/1/j.1468-3083.2011.03998.x.pd

V559A and N822I double KIT mutant melanoma with predictable response to imatinib?

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/88125/1/j.1755-148X.2010.00822.x.pd

hTERT expression in melanocytic lesions: an immunohistochemical study on paraffin-embedded tissue

Telomerase plays a role in the immortalization of cells and carcinogenesis. Previous studies have yielded conflicting results on whether human telomerase RNA (hTER) expression differs in nevi, atypical nevi and melanomas using polymerase chain reaction-based telomeric repeat amplification protocol or in situ hybridization assays. The aim of this study was to evaluate human telomerase reverse transcriptase (hTERT) staining in melanocytic lesions on paraffin-embedded tissues. Methods:  Paraffin-embedded sections from 12 acquired nevi, seven dysplastic nevi, 11 Spitz nevi, eight primary invasive melanomas, and three metastatic melanomas were studied for staining intensity (0–3+) and percentage of labeled cells with anti-hTERT. Results:  hTERT staining was observed in most cells (>75%), in all but three lesions, and was of greater intensity in the nucleus, especially the nucleolus, compared with the cytoplasm. Spitz nevi tended to have weaker hTERT staining (mean = 1.7) compared with acquired nevi (mean = 2.2), dysplastic nevi (mean = 2.4), primary melanomas (mean = 2.4), or metastatic melanomas (mean = 3). Conclusions:  Although telomerase activity was weaker in Spitz nevi, there was overlap with other nevi and primary invasive melanomas in our small series. Thus, hTERT expression does not appear to be a reliable adjunct to the histological diagnosis of primary melanocytic lesions. Fullen DR, Zhu W, Thomas D, Su LD. hTERT expression in melanocytic lesions: an immunohistochemical study on paraffin-embedded tissue.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/75519/1/j.0303-6987.2005.00403.x.pd

S100A6 preferentially labels type C nevus cells and nevic corpuscles: additional support for Schwannian differentiation of intradermal nevi

Melanocytic nevi typically show a morphologic sequence of maturation from epithelioid “type A” cells to fusiform, Schwann cell-like “type C” cells with dermal descent. Nevi may also produce Wagner-Meissner-like structures (nevic corpuscles). Previous studies have shown that this maturation of intradermal nevi recapitulates intermediate stages in Schwann cell development. In intradermal nevi, we have evaluated the pattern of S100A6 protein, a form of S100 found in Schwann cells. Methods: Formalin-fixed, paraffin-embedded archival tissues were evaluated by immunohistochemistry using antibodies specific for S100A6 and S100B in 38 intradermal nevi (IDN). Ten neurofibromas (NF), 3 Schwannomas (SCH), 2 palisaded and encapsulated neuromas (PEN), and 2 granular cell tumors (GCT) were included as positive controls since these lesions have large numbers of Schwann cells. Results: Melanocytic nevi demonstrated preferential anti-S100A6 staining of “type C” cells (36/38; 28 strong, 8 weak) and nevic corpuscles (25/38; 19 strong, 6 weak) compared to “type A” cells (17/38; 17 weak) and “type B” cells (17/38; 4 strong, 13 weak). All NF, SCH, and PEN stained strongly with anti-S100A6. Both GCT were negative with anti-S100A6 but positive with anti-S100B. Conclusions: The pattern of S100A6 expression in intradermal nevi further supports the hypothesis that maturation in these lesions recapitulates features of Schwann cell differentiation. The lack of S100A6 expression by both GCT suggests that these lesions have lost this feature of Schwann cells, which may play a role in their peculiar phenotypic appearance.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/75660/1/j.1600-0560.2001.028008393.x.pd

Rosette‐like structures in the spectrum of spitzoid tumors

Background Spitz nevi demonstrate a diverse spectrum of morphologies. Recently, there have been two reported examples of Spitz nevi with rosette‐like structures similar to Homer‐Wright rosettes. Rosettes have also been described in melanomas and in a proliferative nodule arising in a congenital nevus. Methods A retrospective review of 104 cases of Spitz nevi and variants (n = 51), pigmented spindle cell nevi (n = 26), combined melanocytic nevi with features of Spitz (n = 8), atypical Spitz tumor ( AST , n = 9), and spitzoid melanoma (n = 10). Results Rosette‐like structures were present in 3 of the 104 cases (2.9%), including a compound Spitz nevus, a desmoplastic Spitz nevus, and an AST . All three cases demonstrated several foci of small nests of epithelioid cells with peripherally palisaded nuclei arranged around a central area of fibrillar eosinophilic cytoplasm. Immunohistochemical staining of the three spitzoid lesions demonstrated that the rosette‐like structures express S100 protein, Melan‐A, and neuron specific enolase ( NSE ) and lacked expression of neurofilament, glial fibrillary acidic protein and synaptophysin. Conclusions While uncommon, rosette‐like structures can occur as a focal feature in Spitz nevi and AST . Rosette‐like structures may represent a normal morphologic finding in Spitz nevi, and awareness of them may prevent misdiagnosis as a neural tumor or melanoma.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/99651/1/cup12192.pd

Chronic ulcerative stomatitis: Case series of an under‐recognized entity

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/146622/1/cup13347_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/146622/2/cup13347.pd

The expression of CD23 in cutaneous non-lymphoid neoplasms

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73682/1/j.1600-0560.2006.00685.x.pd

Malignant melanoma with osteosarcomatous differentiation in a lymph node metastasis

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/145523/1/cup13283.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/145523/2/cup13283_am.pd

Revisiting the issue: can the reading for serologic reactivity following 37°C incubation be omitted?

Omitting the 37°C reading from screening tests for unexpected antibodies results in failure to detect some Rh, K, and Jk agglutinins of potential significance (wanted positives). However, this measure avoids unwanted positive tests due to cold agglutinins. STUDY DESIGN AND METHODS : Using data from prior publications, actual risk calculations (ARCs) were made to predict the risk of eliminating the 37°C reading, pretransfusion direct antiglobulin test (DAT), and routine indirect antiglobulin crossmatch (IAT-XM). ARCs used the equation: wanted positives missed × 0.34 (or 0.80) × 5 × percent antigen-positive, where 0.34 = percent of patients transfused (ARCs for 37°C reading and DAT); 0.80 = percent of crossmatched patients transfused (ARCs for IAT-XM); 5 = average number of units transfused. Following elimination of the 37°C reading, the impact of this change on patient care was monitored. Antibody detection and identification data and transfusion reaction reports for 6 months after the change were reviewed. Recently transfused patients with new antibodies were evaluated for immune hemolysis by review of clinical and laboratory data. The findings were compared with those from the same dates of the preceding year. RESULTS : The risk of transfusing incompatible blood by eliminating the DAT, IAT-XM, and 37°C reading is approximately 1:13,000, 1:2,000, and 1:2,400 units transfused, respectively. The cumulative risk from eliminating all three tests is approximately. 1:1,000 units. With respect to the 37°C reading, there were no differences between the pre-change and post-change study periods in the incidence of reported transfusion reactions or cases of immune hemolysis associated with newly formed antibodies. However, unwanted positive tests decreased from 162 to 61 following elimination of the 37°C reading. This represents a decrease of 20 percent in the number of samples requiring antibody identification annually. CONCLUSIONS : Eliminating the 37°C reading from pretransfusion antibody screening tests imposes less risk than omitting the routine IAT-XM, and it avoids the time and costs of evaluating unwanted positive tests, thus reducing expenditures and delays in patient care.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/74728/1/j.1537-2995.1999.39399219287.x.pd