Napsin A is a useful marker for metastatic adenocarcinomas of pulmonary origin

Abstract

These data suggest that napsin A may be a useful marker for identifying metastatic adenocarcinomas of pulmonary origin in combination with TTF-1.

Napsin A is frequently expressed in clear cell carcinoma of the ovary and endometrium

“…Our findings in ovarian nonmucinous carcinomas are consistent with previous studies, in which napsin A overexpression has been observed almost exclusively in O-CCC [10][11][12][13] but only in up to 10% of O-EC and less than 1% of HGSC cases [10][11][12]. The distinction between O-CCC and HGSC is important because they differ in chemotherapeutic response, risk of thromboembolic complications, pattern of recurrence, prognosis, and association with specific genetic syndromes (ie, the association of O-CCC in young patients with Lynch syndrome and of HGSC with germline BRCA1 and/or BRCA2 mutations).…”

“…The present data demonstrate that napsin A is an additional marker that is useful for O-CCC diagnosis. Our findings of napsin A expression in 66.7% of EM-CCCs and 4.5% of EM-ECs are also consistent with previous reports revealing its expression in 67% to 93% of EM-CCC and in less than 10% of EM-EC [9,11,[14][15][16][17]. Most EM carcinomas are of the low-grade endometrioid type (grade 1 and grade 2), confined to the uterus, and are associated with a favorable prognosis.…”

“…Thyroid transcription factor 1 is a nuclear protein expressed in the epithelial cells of the thyroid, type II pneumocytes, and Clara cells in the lung. Its expression has been reported in most primary pulmonary adenocarcinomas (70%-83%) [1,5,[21][22][23] and thyroid papillary carcinomas (97%-100%) [8,24] and less often in other primary sites, including the gastrointestinal tract, kidney, urinary bladder, and prostate, and in gynecologic tumors [10,11,22,23,[25][26][27][28]. One study reported that only a small fraction of pulmonary adenocarcinomas were TTF-1(−)/napsin A(−) (9.2%) or TTF-1(−)/napsin A(+) (8.3%), whereas most (79.2%) were double positive for napsin A and TTF-1 [21].…”

“…Napsin A expression in EM-CCC has been observed in 67%-93% of the cases [11,[14][15][16][17]. The present study investigated the napsin A expression in O-CCC and EM-CCC and compared the former with expression in other ovarian carcinomas, including ovarian EC (O-EC) and HGSC, and the latter with expression in EM-EC.…”

“…Recent studies have reported napsin A expression in a subset of ovarian clear cell carcinomas (O-CCCs, 69%-100%) as well as in up to 10% of ovarian and 6%-10% of endometrial (EM) endometrioid carcinomas (EC); in contrast, it is rarely found in high-grade serous carcinoma (HGSC) [7,[9][10][11][12][13]. Napsin A expression in EM-CCC has been observed in 67%-93% of the cases [11,[14][15][16][17].…”