Department of Laboratory Medicine and Pathology, University of Minnesota, 420 Delaware St. SE, 55455, Minneapolis, MN, USA.
Diagn Pathol. 2021 May 16;16(1):43. doi: 10.1186/s13000-021-01106-2.
Percutaneous needle biopsy of renal masses has been increasingly utilized to aid the diagnosis and guide management. It is generally considered as a safe procedure. However, tumor seeding along the needle tract, one of the complications, theoretically poses potential risk of tumor spread by seeded malignant cells. Prior studies on the frequency of needle tract seeding in renal tumor biopsies are limited and clinical significance of biopsy-associated tumor seeding remains largely controversial.
Here we investigated the frequencies of biopsy needle tract tumor seeding at our institution by reviewing the histology of renal cell carcinoma nephrectomy specimens with a prior biopsy within the last seventeen years. Biopsy site changes were recognized as a combination of foreign body reaction, hemosiderin deposition, fibrosis and fat necrosis. The histologic evidence of needle tract tumor seeding was identified as clusters of tumor cells embedded in perinephric tissue spatially associated with the biopsy site. In addition, association between parameters of biopsy techniques and tumor seeding were investigated.
We observed needle tract tumor seeding to perinephric tissue in six out of ninety-eight (6 %) renal cell carcinoma cases including clear cell renal cell carcinoma, papillary renal cell carcinoma, chromophobe, and clear cell papillary renal cell carcinoma. The needle tract tumor seeding was exclusively observed in papillary renal cell carcinomas (6/28, 21 %) that were unifocal, small-sized (≤ 4 cm), confined to the kidney and had type 1 features. No recurrence or metastasis was observed in the papillary renal cell carcinoma cases with tumor seeding or the stage-matched cases without tumor seeding.
Our study demonstrated a higher than reported frequency of needle tract tumor seeding. Effective communication between pathologists and clinicians as well as documentation of tumor seeding is recommended. Further studies with a larger patient cohort and longer follow up to evaluate the impact of needle tract tumor seeding on long term prognosis are needed. This may also help reach a consensus on appropriate pathologic staging of renal cell carcinoma when the only site of perinephric fat invasion is within a biopsy needle tract.
经皮肾肿块穿刺活检术已越来越多地被用于辅助诊断和指导治疗。通常认为该操作是安全的。然而，肿瘤沿针道种植，作为一种并发症，理论上存在恶性细胞种植导致肿瘤扩散的潜在风险。之前关于肾肿瘤活检中针道种植频率的研究有限，活检相关肿瘤种植的临床意义仍存在很大争议。
我们通过回顾过去 17 年来在我院进行的肾细胞癌根治性肾切除标本的组织学检查，研究了肿瘤在活检针道中的种植频率。活检部位的变化被认为是异物反应、含铁血黄素沉积、纤维化和脂肪坏死的综合表现。针道肿瘤种植的组织学证据是肿瘤细胞簇嵌入肾周组织，与活检部位在空间上相关。此外，还研究了活检技术参数与肿瘤种植之间的关系。
我们观察到 98 例肾细胞癌中有 6 例（6%）肾周组织有肿瘤种植，包括透明细胞癌、乳头状肾细胞癌、嫌色细胞癌和透明细胞乳头状肾细胞癌。肿瘤种植仅见于 6/28 例（21%）的乳头状肾细胞癌，这些肿瘤为单灶、小肿瘤（≤4cm）、局限于肾脏且具有 1 型特征。在有肿瘤种植的乳头状肾细胞癌病例或无肿瘤种植的匹配病例中，均未观察到复发或转移。
我们的研究表明，肿瘤种植的频率高于报道的频率。建议病理学家和临床医生之间进行有效的沟通，并记录肿瘤种植情况。需要进一步进行更大患者队列和更长时间随访的研究，以评估肿瘤种植对长期预后的影响。这也有助于在肾周脂肪侵犯仅位于活检针道内时，就肿瘤种植对肾细胞癌进行适当的病理分期达成共识。
