[1201] Late Recurring Uterine Smooth Muscle Tumors Constitute a Heterogeneous Collection of Leiomyosarcomas and STUMPs

E Veras, O Zivanovic, L Jacks, M Hensley, R Soslow. Memorial Sloan-Kettering Cancer Center, New York, NY

Background: Reliable pathologic predictors of clinical outcome have yet to be determined for uterine leiomyosarcoma (LMS). The literature suggests a correlation between tumor grade and clinical behavior. We studied the pathologic features of uterine smooth muscle tumors with late recurrences, a surrogate for clinically low grade behavior, in an attempt to learn which histologic features correlated with a protracted clinical course.
Design: The Murray Brennan Sarcoma Database and pathology records were reviewed to access STUMPs and LMSs with recurrence and long disease-free intervals, defined as recurrence ≥ 5 years of diagnosis. Stanford diagnostic criteria were used.
Results: 21 cases were retrieved from the database. Slides were available for review in only 9 cases, only 5 of which were LMSs. The cases from the sarcoma database represented approximately 3% of all LMSs.

Initial Diagnosis	Mitosis / 10 HPFs	Cytologic Atypia / Necrosis	Review Diagnosis (2009)	Size (cm)	Status	Time to Recurrence (Years)
Atypical cellular LM of uncertain malignant potential with epithelioid features	5	P (mild/diffuse) / A	Atypical LM	8	AWD	9.188
Atypical smooth muscle tumor	2	(moderate/diffuse) / A	ALMLRR	7	AWD	16.229
Infarcted smooth muscle tumor of uncertain malignant potential	2	P (mild/diffuse) / A	ALMLRR	15	AWD	13.103
LMS, low grade	8	P (mild/diffuse) / A	ALMLRR	10	AWD	9.798
LMS, high grade	>20	P (marked/diffuse) / P	LMS	5	AWD	5.486
LMS, low grade	12 (including atypical)	P (marked/diffuse) / P	LMS	N/A	AWD	7.978
LMS, high grade	11	P (marked/diffuse) / P	LMS with epithelioid features	20	AWD	6.822
LMS	7	P (marked/diffuse) / P	LMS	8	DOD	5.092
LMS arising in LM	28	P (marked/diffuse) / P	LMS	8	DOD	5.905

A: absent; ALMLRR: atypical leiomyoma with low recurrence rate; AWD: alive with disease; DOD: dead of disease; LM: leiomyoma; LMS: leiomyosarcoma; P: present


Conclusions: Late recurring smooth muscle tumors are extremely rare and only approximately half of them meet Stanford criteria for LMS. Late recurring LMSs exhibit high grade histologic features that are similar to other conventional LMSs. Late recurring STUMPs may represent low grade leiomyosarcomas, but additional work is needed to define diagnostic criteria that can be used prospectively.
Category: Gynecologic & Obstetrics

Monday, March 22, 2010 8:15 AM

Platform Session: Section D, Monday Morning