Adenomatoid Tumors of the Uterus: An Analysis of 60 Cases

Abstract

Sixty cases of uterine adenomatoid tumors (ATs) are reported. All except four were incidental findings in hysterectomy specimens, three of these being discovered preoperatively as large multicystic tumors. ATs were classified into two distinctive macroscopic patterns: small, solid tumors and large, cystic ones. The 56 small, solid ATs ranged from 0.2 to 3.5 cm, (average 2.1 cm); 48 were nodular and 8 diffuse. The four large, cystic tumors ranged from 7 to 10 cm. Inflammation occurred in 65% of the tumors, and a smooth muscle reaction, identified by an increased Ki-67 index, was present in most cases. Both types were histologically similar except for the presence of short papillae in cystic tumors, which also showed serosal involvement. Both were immunoreactive for cytokeratins, calretinin, HMBE-1, and vimentin. Estrogen and progesterone nuclear receptors and EMA were negative. These tumors represent a spectrum ranging from small and solid to large and cystic ATs in the female genital tract, whereas outside the genital tract they are morphologically similar to multicystic mesothelioma. Although a reactive origin for ATs often seems plausible, especially when inflammation is present, their neoplastic nature should not be ignored.

Adenomatoid tumors of the female and male genital tracts: a clinicopathological and immunohistochemical study of 44 cases

“…In that report, an incidence of 50% was observed, which is still significantly lower than that observed in male sites. 25 Although a definitive etiology for gender differences in associated chronic inflammation in adenomatoid tumors is uncertain, we speculate that sites more prone to trauma (testis/ epididymis versus uterus) may account for this disparity. In contrast, the presence of thread-like bridging strands traversing tubular spaces ( Figure 1g) appears to be a reproducible corroborative diagnostic feature for genital tract adenomatoid tumors regardless of gender, although it may require diligent search to identify them.…”

“…Variably described as follicular inflammatory infiltrates, lymphocyte collections, chronic lymphoid follicles, or lymphoid aggregates (with or without germinal centers), 19,22,25,[34][35][36] these chronic inflammatory cell clusters/follicles have been reported to be useful diagnostic features of all genital tract adenomatoid tumors 36,37 despite a lack of formal appraisal across gender and site. Although an initial study in uterine/fallopian tube adenomatoid tumors reported 'inflammation' in up to 80% of cases, 35 only one other study to our knowledge has formally evaluated lymphoid aggregates in uterine adenomatoid tumors.…”

Uterine Tumors Resembling Ovarian Sex Cord Tumors

“…11,[20][21][22][23][24][25] Other conditions that may enter into the differential diagnostic consideration less frequently are adenosarcoma, carcinosarcoma, perivascular epithelioid cell tumor, and adenomatoid tumor. [26][27][28][29][30][31][32] Epithelioid leiomyoma is a form of uterine leiomyoma with more than 50% round to polygonal cells. Epithelioid leiomyoma and UTROSCT show striking macroscopic resemblance.…”

The Utility of Immunohistochemistry in the Differential Diagnosis of Gynecologic Disorders

“…Adenomatoid tumor is positive for the mesothelial markers CK5/6, calretinin, and WT1, 220,221 and negative for the epithelial markers BerEP4 and CEA. 222 Similarly, immunohistochemistry helps in differentiating FATWO, a rare tumor arising in the broad ligament, mesosalpinx, and ovary, 58 from the low-grade endometrioid adenocarcinoma variant of the fallopian tube.…”