[536] Comparative Analysis of Spitz Tumors: A Clinicopathologic Follow-Up of 163 Cases

A Sepehr, E Chao, MC Mihm, Jr, H Tsao. Beth Israel Deaconess Medical Center, Boston; Massachusetts General Hospital, Boston; Harvard Medical School, Boston

Background: The discrimination of the benign from malignant variants of Spitz tumor has been a great challenge in dermatopathology. A few grading systems have been proposed and categorized them into classic Spitz tumor/nevus without atypicality (CST) with low, atypical Spitz tumor (AST) with intermediate, or Spitzoid melanoma with high risk, based on a combination of clinical and pathologic parameters, however, there is lack of consensus for gauging their malignant potential. Studies on Spitz tumors have suffered from short follow-up period and/or limited number of cases. There is a chance of lymph node metastasis in a subset of cases, but its impact on survival is unknown. The current study is designed with the goal to compare the classic Spitz tumor/nevus (CST), and the atypical Spitz tumor (AST) with clinicopathologic follow-up in regards to their behavior and prognosis.
Design: During1987-2002, all cases of primary Spitz tumor in the database of Pathology Dept at MGH were included. CSTs and ASTs were diagnosed and discriminated based on organizational, proliferation, and cytologic criteria as previously published. The database of the Pigmented Lesion Clinic at MGH was cross-linked to obtain clinical follow-up information on each patient.
Results: Spitz tumors (n=163, median age=29.1 yrs) with long term clinical follow-up (median= 6.7 yrs) were included and were divided in CST (n=71) and AST (n=92) groups. CSTs mean age was 24.2 yrs vs. 32.9 for AST (p<.001). Lesions were common on the extremities (94/163, 57.7%) with no difference in site predilection (p=NS). Sentinel lymph node biopsies were performed on 6/92 patients with AST; one person had a nodal involvement who underwent a negative completion lymph node dissection and one year of high dose interferon, currently 8 yrs post diagnosis and disease free. One case of metastases in a patient with AST and concurrent history of an intermediate thickness melanoma (1.2 mm, level IV) was seen. All other patients were disease free.
Conclusions: We report the largest series with the longest follow up data to date on the outcome of Spitz tumors. After a median follow-up period of 6.7 yrs, we did not detect any fatalities; only one patient in stage IV disease who had a concurrent intermediate thickness melanoma. Prognosis is thus, highly favorable for both the classic and atypical Spitz tumors.
Category: Dermatopathology

Wednesday, March 24, 2010 1:00 PM

Poster Session VI # 73, Wednesday Afternoon


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