BACKGROUND: Spitz nevi and Spitzoid melanomas show overlapping histopathologic features, often making the diagnosis challenging. The p16 protein functions as a tumor suppressor and loss of its expression may be seen in some melanomas. METHODS: We evaluated 18 Spitz nevi and 19 Spitzoid melanomas from the Yale Spitzoid Neoplasm Repository for p16 expression. A staining intensity score (SIS) was calculated by multiplying a score for the percentage of stained cells (0-3) by a score for staining intensity (0-3). RESULTS: Staining with p16 was positive in 15/18 (83%) Spitz nevi and 15/19 (79%) Spitzoid melanomas (p = 0.73). Both Spitz nevi and Spitzoid melanomas had a similar SISs, 4.9 and 3.8, respectively (p = 0.057). All 19 patients with Spitzoid melanomas had poor outcome with either death (6 patients) or metastases (13 patients) at a median (3 years) and mean (5.4 years) follow up. In contrast, all 18 patients with Spitz nevi had a benign course with no adverse events at a median (4 years) and mean (4 years) follow up. CONCLUSIONS: We found no significant difference in p16 staining in Spitz nevi and Spitzoid melanomas. We conclude that p16 does not appear to be a useful immunohistochemical marker in distinguishing between Spitz nevi and Spitzoid melanomas.
BACKGROUND: Spitz nevi and Spitzoid melanomas show overlapping histopathologic features, often making the diagnosis challenging. The p16 protein functions as a tumor suppressor and loss of its expression may be seen in some melanomas. METHODS: We evaluated 18 Spitz nevi and 19 Spitzoid melanomas from the Yale Spitzoid Neoplasm Repository for p16 expression. A staining intensity score (SIS) was calculated by multiplying a score for the percentage of stained cells (0-3) by a score for staining intensity (0-3). RESULTS: Staining with p16 was positive in 15/18 (83%) Spitz nevi and 15/19 (79%) Spitzoid melanomas (p = 0.73). Both Spitz nevi and Spitzoid melanomas had a similar SISs, 4.9 and 3.8, respectively (p = 0.057). All 19 patients with Spitzoid melanomas had poor outcome with either death (6 patients) or metastases (13 patients) at a median (3 years) and mean (5.4 years) follow up. In contrast, all 18 patients with Spitz nevi had a benign course with no adverse events at a median (4 years) and mean (4 years) follow up. CONCLUSIONS: We found no significant difference in p16 staining in Spitz nevi and Spitzoid melanomas. We conclude that p16 does not appear to be a useful immunohistochemical marker in distinguishing between Spitz nevi and Spitzoid melanomas.
Authors: Anna Eisenstein; Izabela P Panova; Hye J Chung; Lynne J Goldberg; Qing Zhang; Rossitza Lazova; Jag Bhawan; Klaus J Busam; James T Symanowski; Rhoda M Alani; Byungwoo Ryu Journal: Melanoma Res Date: 2018-02 Impact factor: 3.599
Authors: Sophia A Ma; Conor P O'Day; Tzvete Dentchev; Junko Takeshita; Todd W Ridky; John T Seykora; Emily Y Chu Journal: J Cutan Pathol Date: 2019-02-14 Impact factor: 1.587
Authors: Lisa M Hillen; Milan S Geybels; Ivelina Spassova; Jürgen C Becker; Thilo Gambichler; Marjan Garmyn; Axel Zur Hausen; Joost van den Oord; Véronique Winnepenninckx Journal: FEBS Open Bio Date: 2020-06-05 Impact factor: 2.693