[1826] Metastatic Endometrial Stromal Sarcoma in the Lung: Importance of Immunohistochemical Staining, Clinical History and Imaging Studies

MJ Mentrikoski, C Zhao, J Zhang, HL Wang, LA McMahon, Q Yang, F Li, H Xu. University of Rochester Medical Center, Rochester; University of Pittsburgh Medical Center, Pittsburgh; Mayo Clinic, Rochester; Cedars-Sinai Medical Center, Los Angeles

Background: Discrimination between metastatic pulmonary endometrial stromal sarcoma (ESS) and other spindle cell neoplasms including solitary fibrous tumor, and sarcomatoid carcinoma and mesothelioma can be challenging when diagnostic material is a small and crushed core biopsy and when clinical history is lacking. Immunohistochemical staining can be a powerful tool to segregate ESS from others; however, it may be a pitfall because a portion of ESS cases were reported to be positive for cytokeratin. Here we assessed the importance of a panel of immunostaining, clinical history and imaging studies in rendering this diagnosis.
Design: Eleven cases of metastatic pulmonary ESS surgically resected (n=10) or biopsied (n=1) were retrieved. Clinical and imaging data were available for analysis. Lung histologic slides were reviewed and the immunohistochemical staining panel including AE1/AE3, CK7, CK19, Cam5.2, CD10, bcl-2, CD34, TTF-1, ER, PR, and caldesmon were performed. Percentage and intensity of stained tumor cells were recorded.
Results: Seven cases of metastatic lung ESS were low grade (LGESS) and 4 were high grade (HGESS). Patients ranged in age from 44 to 70 years for LGESS and from 50 to 73 years for HGESS, respectively. All the cases presented with one to multiple unilateral or bilateral lung nodules detected by CT. Primary ESS was diagnosed from hysterectomy specimens except one by endometrial biopsy, 0.5 to 23 years prior to metastasis. Immunohistochemical studies showed that all ESS cases were moderately to strongly positive for bcl-2 and CD10 with >50% of tumor cells stained except one HGESS being negative for CD10. ER and PR neagtive were detected in 7 cases with diffuse and moderate to strong positivity. Three ER and PR negative cases were HGESS. TTF-1, CK7 and CD34 were neative in all cases. One LGESS and one HGESS were positive for caldesmon with patchy and strong positivity. Interestingly, two cases of LGESS showed moderate to strong AE1/AE3 positivity in >50% of tumor cells with one case having moderate CK19 and Cam 5.2 staining in >30% of tumor cells.
Conclusions: Caution should be taken when assessing spindle cell neoplasms in female patients with a history of hysterectomy. A panel of immunohistochemical staining and imaging studies are useful in nailing down the diagnosis.
Category: Pulmonary

Wednesday, March 24, 2010 9:30 AM

Poster Session V # 251, Wednesday Morning


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