Department of Dermatology, Stanford University School of Medicine, Redwood City, California.
Department of Dermatology, Stanford University School of Medicine, Redwood City, California2Department of Pathology, Stanford University School of Medicine, Stanford, California.
JAMA Dermatol. 2014 Sep;150(9):970-3. doi: 10.1001/jamadermatol.2014.583.
Vismodegib is a Hedgehog signaling pathway inhibitor recently approved by the US Food and Drug Administration for advanced basal cell carcinoma. We present 2 cases of clinically significant squamous cell carcinoma within the tumor bed of locally advanced basal cell carcinoma found during vismodegib treatment.
The first case is that of a patient with locally advanced basal cell carcinoma responsive to vismodegib but with an enlarging papule within the tumor bed. On biopsy, this papule was an invasive acantholytic squamous cell carcinoma. The second case is that of a patient with Gorlin syndrome with a locally advanced basal cell carcinoma that was stable while the patient was receiving therapy with vismodegib for 2.5 years but subsequently increased in size. Biopsy specimens from this tumor showed invasive squamous cell carcinoma, spindle cell subtype. In both cases, the squamous cell carcinomas were surgically resected.
These cases highlight the importance of repeated biopsy in locally advanced basal cell carcinomas in 2 clinical situations: (1) when an area within the tumor responds differentially to vismodegib, and (2) when a tumor stops being suppressed by vismodegib. Timely diagnosis of non-basal cell histologic characteristics is critical to institution of effective therapy.
维莫德吉是一种 Hedgehog 信号通路抑制剂，最近被美国食品和药物管理局批准用于治疗晚期基底细胞癌。我们报告了 2 例在维莫德吉治疗期间局部晚期基底细胞癌瘤床中发现的临床上显著的鳞状细胞癌病例。
第一个病例是一例局部晚期基底细胞癌患者，对维莫德吉有反应，但在瘤床内出现一个增大的丘疹。活检时，这个丘疹是侵袭性棘层松解性鳞状细胞癌。第二个病例是一例患有 Gorlin 综合征的患者，局部晚期基底细胞癌在接受维莫德吉治疗 2.5 年期间稳定，但随后增大。该肿瘤的活检标本显示为侵袭性鳞状细胞癌，梭形细胞亚型。在这两种情况下，鳞状细胞癌均通过手术切除。
这些病例强调了在两种临床情况下对局部晚期基底细胞癌进行重复活检的重要性：（1）当肿瘤内的一个区域对维莫德吉的反应不同时，（2）当肿瘤停止被维莫德吉抑制时。及时诊断非基底细胞组织学特征对于实施有效治疗至关重要。
