Ohishi Yoshihiro, Kaku Tsunehisa, Kobayashi Hiroaki, Aishima Shinichi, Umekita Yoshihisa, Wake Norio, Tsuneyoshi Masazumi
Department of Anatomic Pathology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
Hum Pathol. 2008 Oct;39(10):1446-53. doi: 10.1016/j.humpath.2008.02.006. Epub 2008 Jul 11.
The major differential diagnostic problem presented by atypical polypoid adenomyofibroma (atypical polypoid adenomyoma) (APA), which usually affects young women, is the exclusion of well-differentiated endometrial carcinoma invading the myometrium. This distinction, however, is of great clinical importance from the standpoint of treatment because reproductive conservation is feasible for patients with APA. Recently, CD10, known to be a marker of endometrial stromal cells, was reported to be also expressed in cells immediately surrounding the neoplastic glands invading the myometrium [Am J Surg Pathol 27 (2003) 786-789; Mod Pathol 16(1) (2003) 22-27]. However, CD10 expression in the myofibromatous component of APA has not been previously examined in the literature. We therefore decided to examine whether the CD10-immunostaining pattern in APA is different from that in myoinvasive carcinoma. Furthermore, we also attempted to obtain any histopathologic findings that may offer some insight regarding the histogenesis of APA. Seven cases of APA were immunostained for CD10 using curettage or polypectomy specimens, in addition to hysterectomy specimens in 1 case. Areas with more fibrotic rather than muscular stroma were focally observed in 4 cases. The pattern of staining was compared with hysterectomy specimens taken from 19 cases in which well- to moderately differentiated endometrioid adenocarcinoma had deeply invaded the myometrium (outer two thirds of the myometrium) but was not associated with adenomyosis. In 6 of 7 cases of APA, CD10 was never expressed in the myofibromatous stromal components. In 1 case of APA, the fascicles of fibrotic and muscular mesenchymal cells in the interglandular areas were focally and weakly positive for CD10. All 19 myoinvasive carcinomas expressed CD10 to some extent in cells immediately surrounding the neoplastic myoinvasive glands (fringe-like staining pattern). The proportion of the myoinvasive nests immediately surrounded by CD10-positive mesenchymal cells was as follows: mean, 74%; median, 80%; minimum, 5%; maximum, 100%. The fringe-like CD10-staining pattern was not observed in APA. Furthermore, we identified a gradual transformation from preexisting endometrial stromal cells (CD10 positive) into the typical myofibromatous stromal component (CD10 negative) of APA in 1 case. In conclusion, this study demonstrated differences in the CD10 immunoreactivity or immunostaining pattern between the stromal components of APA and myoinvasive endometrial carcinoma. This difference should lead to a more accurate diagnosis of APA (pseudo-myoinvasive lesion). Furthermore, the histogenesis of APA may perhaps be explained by "myofibromatous metaplasia" of the endometrial stromal cells.
非典型息肉状腺肌纤维瘤（非典型息肉状腺瘤）（APA）通常发生于年轻女性，其主要的鉴别诊断问题是排除侵犯肌层的高分化子宫内膜癌。然而，从治疗角度来看，这种区分具有重要的临床意义，因为APA患者可行保留生育功能的治疗。最近，已知作为子宫内膜间质细胞标志物的CD10，据报道在侵犯肌层的肿瘤性腺体周围的细胞中也有表达[《美国外科病理学杂志》27 (2003) 786 - 789；《现代病理学》16(1) (2003) 22 - 27]。然而，APA肌纤维瘤成分中CD10的表达此前尚未见文献报道。因此，我们决定研究APA中CD10免疫染色模式是否与肌层浸润性癌不同。此外，我们还试图获得任何可能有助于了解APA组织发生的组织病理学发现。7例APA病例除1例采用子宫切除标本外，其余均采用刮宫或息肉切除标本进行CD10免疫染色。4例局部观察到纤维组织多于肌肉组织的间质区域。将染色模式与19例子宫切除标本进行比较，这些标本中高分化至中分化的子宫内膜样腺癌已深深侵犯肌层（肌层外三分之二）但未合并子宫腺肌病。7例APA病例中有6例，CD10在肌纤维瘤间质成分中从未表达。1例APA病例中，腺间区域的纤维性和肌肉性间充质细胞束局部呈弱阳性。所有19例肌层浸润性癌在肿瘤性肌层浸润腺体周围的细胞中均有不同程度的CD10表达（边缘样染色模式）。被CD10阳性间充质细胞立即包围的肌层浸润巢的比例如下：平均值为74%；中位数为80%；最小值为5%；最大值为100%。APA中未观察到边缘样CD10染色模式。此外，我们在1例病例中发现，APA中存在从先前存在的子宫内膜间质细胞（CD10阳性）逐渐转变为典型的肌纤维瘤间质成分（CD10阴性）的现象。总之，本研究证明了APA间质成分与肌层浸润性子宫内膜癌在CD10免疫反应性或免疫染色模式上存在差异。这种差异有助于更准确地诊断APA（假肌层浸润性病变）。此外，APA的组织发生可能可以用子宫内膜间质细胞的“肌纤维瘤化生”来解释。
