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Minute perivascular epithelioid cell ( PEC ) nests in the abdominal lymph nodes—a putative precursor of PEComa
Author(s) -
Nagasaka Toru,
Murakami Yoshiko,
Sasaki Eiichi,
Hosoda Waki,
Nakanishi Toru,
Yatabe Yasushi
Publication year - 2015
Publication title -
pathology international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.73
H-Index - 74
eISSN - 1440-1827
pISSN - 1320-5463
DOI - 10.1111/pin.12262
Subject(s) - perivascular epithelioid cell , pathology , epithelioid cell , lymph node , lymph , population , biology , anatomy , immunohistochemistry , medicine , environmental health
A perivascular epithelioid cell tumor ( PEComa ) is a peculiar growth defined as a mesenchymal tumor composed of histologically and immunohistochemically distinct perivascular epithelioid cells ( PECs ). Because neither normal counterparts nor precursor lesions of PEComa have been identified, we examined minute PEC nests, ranged from 0.8 mm to 10 mm, to investigate the possible origin of the PEComa . We examined a total of 80 677 para‐aortic and pelvic lymph nodes that were systematically dissected from 1656 patients for gynecological malignancies. The identified lesions were confirmed immunohistochemically with multiple PEC markers, including smooth muscle actin, HMB45 , melan‐ A , MiTF , ER and PgR . A total of 66 minute PEC nests were found in 21 patients (1.3% of the total population) with an average frequency of 3.1 lesions per patient. In cases of multiple involvement, 11 of 13 nests were located at the same level of multiple lymph node or on continuous levels. The lesions were preferentially distributed at the level of para‐aortic and high pelvic lymph nodes. All nests were positive for actin and HMB45 , whereas the other markers were positive with varying frequencies. The minute PEC nests may be associated with the possible normal counterpart of PEComas .