[1167] Mesonephric Adenocarcinoma of the Uterus and Cervix – A Clinicopathologic Study of 10 Cases

Cynthia Jimenez, Marisa Nucci, Charles Zaloudek. UCSF, San Francisco, CA; Brigham and Women's Hospital, Boston, MA

Background: Mesonephric adenocarcinoma (MA) is a rare type of adenocarcinoma that occurs mainly in the cervix and less often in the uterine corpus. It must be differentiated from diffuse mesonephric hyperplasia and other types of adenocarcinoma. We investigated the clinicopathologic features of 10 mesonephric adenocarcinomas including 7 of the cervix and 3 of the uterine corpus.
Design: Clinical information and follow-up data was obtained from physicians and medical records. The gross pathologic findings were abstracted from pathology reports. Microscopic and immunohistochemical features were evaluated in the tumors and in adjacent mesonephric hyperplasia.
Results: The mean age was 52 years. Nine women had a hysterectomy, with bilateral salpingo-oophorectomy in 3, 5 had lymph-node dissections; 2 pelvic radiation. All patients with cervical MA were stage 1B while 2/3 with corpus MA were stage IIIC or higher. Average follow-up was 5 years. Microscopically, tubular, glandular, retiform, sieve-like, spindle cell and solid growth patterns were observed. Tumor cells were low columnar to cuboidal, had scant cytoplasm and moderately atypical hyperchromatic nuclei. The mean mitotic index was 16/10 HPFs. 30% of tumors were associated with diffuse mesonephric hyperplasia. Immunohistochemical findings are presented in Table 1. The mean Ki-67 index was 25% in tumor, 11% in atypical hyperplasia and 5% in remnants.

Table 1. Immunohistochemical Results

	Stain Intensity				Stain distribution
Stains	None	Weak	Moderate	Strong	Focal	Intermediate	Diffuse
PAX2	0%	0%	0%	100%	10%	0%	90%
PAX8	0%	0%	0%	100%	0%	22%	78%
CD10	12%	0%	12%	78%	22%	33%	33%
P16	0%	0%	56%	44%	44%	56%	0%
ER	70%	20%	0%	10%	10%	10%	10%
Calretinin	45%	33%	22%	0%	44%	11%	0%
Vimentin	12%	0%	44%	44%	22%	44%	22%
CEA	80%	0%	20%	0%	10%	10%	0%

Conclusions: Mesonephric adenocarcinoma often occurs in a background of mesonephric hyperplasia. Most cases had diffuse, strong staining for PAX2 and PAX8 but no staining pattern was diagnostic of MA. Areas of confluent growth with one or more of the characteristic patterns differentiate MA from hyperplasia and other types of adenocarcinoma. When there is a purely tubular pattern the boundary between hyperplasia and MA is ambiguous, but greater nuclear atypia, a higher mitotic count and Ki-67 index differentiate MA from hyperplasia and remnants. Diffuse growth of mesonephric tubules in a small specimen raises the possibility of MA and requires further evaluation. The clinical behavior of cervical MA appears similar to other types of adenocarcinoma of similar stage but uterine corpus MA may be more aggressive.
Category: Gynecologic & Obstetrics

Wednesday, March 21, 2012 9:30 AM

Poster Session V # 135, Wednesday Morning