PMC3614382_01
(A) Scanning magnification overview of the endocervical biopsy specimen, with evident fragmentation. (B) Proliferation of glands lined by markedly enlarged, vacuolated clear cells with enlarged hyperchromatic nuclei (medium power). The border between glands and underlying decidualized stroma is regular without desmoplastic changes. Mononuclear cell infiltrates are noted in the decidua. (C) High power view of an area showing glands exhibiting a papillary architecture and lined by cells with more densely eosinophilic cytoplasm. Marked nuclear pleomorphism is seen, as well as several nuclear pseudoinclusions. Mitoses are absent. (D) High power view of ER immunohistochemical stain showing positive nuclear staining in glandular epithelium and decidual stromal cells.
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Histologic examination revealed a focally exuberant proliferation of glandular structures lined by large cells demonstrating prominent clear cell metaplasia and hobnailed luminal protrusions (Figure 1A-C). Focal nuclear pseudoinclusions were noted (Figure 1C). The interface between atypical glands and underlying stroma was smooth, without evidence of invasion or associated desmoplastic response (Figure 1B). The glands were surrounded by decidualized stromal cells, focally admixed with mononuclear cell infiltrates (Figure 1B). Adjacent to the regions involved by Arias-Stella changes, normal appearing glandular epithelium and decidual cells showed positivity for ER, suggestive of endometrial differentiation (Figure 1D).