[1923] Pulmonary Metastatic Nodules of Endometrial Stromal Sarcoma; a Histopathologic Review of 10 Cases

Ji Young Park, Chang Ohk Sung, Sang Yong Song, Jung Ho Han, Se Jin Jang, Kyu-Rae Kim. University of Ulsan College of Medicine, Seoul, Korea; Sungkyunkwan University School of Medicine, Samsung Medical Center, Seoul, Korea

Background: Lung is the most common metastatic site in cases of endometrial stromal sarcoma (ESS). However, the diagnosis on small biopsy specimen is frequently challenging because of relatively low incidence of the tumor, long disease free interval before metastasis, and rarity of pathologic description regarding pulmonary metastatic lesion of ESS, and it is especially true when the pulmonary lesion is the first manifestation of the disease.
Design: We scrutinized histopathologic findings and immunohistochemical features for CD10, estrogen and progesterone receptors, D2-40, and CD31 in 46 metastatic pulmonary nodules from nine patients with low grade ESS and miliary nodules in one patient on wedge resected specimens to seek any helpful findings for the diagnosis of small biopsy samples and to investigate the route of metastases to the lung.
Results: All lesions formed well circumscribed nodules on bilateral lungs with the size ranging from 100μm to 2.3cm. Prominent interstitial collagen deposit (49%), absence of spiral arteriole-like vasculature (27%), microcystic change due to cystic dilatation of bronchiolar lumens (21%), myxoid degeneration (12%), foam cell change (5%), and smooth muscle differentiation (2%) were noted in the metastatic lesion. CD10 decorated normal alveolar septa as well as the tumor cells, but ER was positive only in the tumor cells of all cases. The tumor showed peribronchiolar distribution with characteristic tight subepithelial growth in 59%, perivascular distribution in 35%, and perilymphatic distribution in 49%. One case with numerous miliary micronodules showed mixed patterns of peribronchial, perivascular, perilymphatic, paraseptal and subpleural distributions.
Conclusions: Frequent secondary change in metastatic ESS might be an obstacle for correct diagnosis on small biopsy samples. Thus, awareness of frequent secondary changes, and the distribution patterns will be helpful for the diagnosis. Considering that abundant normal lymphatic channels are distributed around the bronchovascular trees, and within visceral pleura and interlobular septae, and that frequent peribronchiolar distribution of metastatic lesions in our cases with the presence of lymphatic tumor emboli in some cases, lymphatic metastasis might be an important route of pulmonary metastasis.
Category: Pulmonary

Wednesday, March 6, 2013 1:00 PM

Poster Session VI # 300, Wednesday Afternoon


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