前列腺不典型小腺泡增生的病理形态及临床意义

Morphologic diagnosis and clinical significance of prostatic atypical small acinar proliferation suspicious but not diagnostic of cancer

目的探讨前列腺不典型小腺泡增生的形态学特点和临床意义。方法收集解放军总医院病理科2004—2006年前列腺穿刺活检诊断为不典型小腺泡增生病例11例,复习HE和免疫组织化学切片,并对有不典型小腺泡增生病变的蜡块重新进行34βE12、p63和P504S免疫组织化学(SP法)染色,观察不典型小腺泡增生的组织学特点和免疫组织化学表达特点。结果11例不典型小腺泡增生均表现为排列紧凑的小腺体,其中6例小腺泡数量在3个以下,圆形或轻度不规则形,核呈单层排列,有的细胞核之间间隔较大。细胞核普遍增大,圆形或不规则形,部分可见明显的核仁。胞质呈嗜双色性或空亮,腔缘相对平整,部分腔内可见蓝色黏液。免疫组织化学显示34βE12、p63阴性,P504S阳性或弱阳性。4例腺泡数量超过3个,圆形或轻微不规则形,细胞核轻度增大,核仁不清楚或有小核仁。34βE12及p63阴性或点状阳性,P504S弱阳性或阴性。11例患者二次穿刺活检诊断为癌的有4例,多为第一次活检中腺泡数量较少但有明确细胞异型性的病例。结论不典型小腺泡增生是一种与前列腺癌密切相关的病变,其腺体数量或细胞形态或组织结构改变不足以诊断为癌的一类病变。不典型小腺泡增生病例二次活检发现癌的几率明显高于一般的增生。

Objective To study the morphologic features and clinical significance of atypical small acinar proliferation （ASAP） suspicious but not diagnostic of cancer in prostatic biopsies. Methods The slides of 11 cases of prostatic needle biopsies collected during a two-year period with the diagnosis of ASAP were reviewed. Immunohistochemical study for 34βE12, p63 and P504S was performed on the archival paraffin sections. Results All the 11 ASAP cases were characterized by the presence of a few compacted small acini in the prostatic stroma. Six cases had acini of less than three in number. The acini were round or slightly irregular in shape. The nuclei were enlarged, round or irregular, arranged in single layer and focally separated by broad interval. The nucleoli were usually prominent. Cytoplasm was amphophilic or pale and the lumen border was often well-defined. Basophilic mucus was also seen in some of the lumen. Immunohistochemical study for 34βE12 and p63 was negative, while that for P504S was positive. In 4 of the 11 cases, the acini were more than three in number, round or slightly irregular, but without cytologic atypia. The nuclei were slightly enlarged with small or inconspicuous nucleoli. Immunohistochemical study for 34βE12 and p63 was negative or at most focally positive. P504S staining was either negative or weakly positive. Second repeat biopsy was carried out in all cases, and 4 of them （36%） showed definite adenocarcinomatous changes. The positive cases were those with fewer acini but definite cytologic atypia in the initial biopsy. Conclusions ASAP is a morphologic interpretation closely associated with prostatic adenocarcinoma. The histologic features are suspicious of but not diagnostic of cancer, due to insufficient criteria in terms of acinar number, cytologic or architectural abnormalities. The positive rate in subsequent repeat biopsy is higher than that for cases with usual nodular hyperplasia.