Trichoblastic Carcinoma Arising from a Nevus Sebaceous

Safety and efficacy of the anti-PD1 immunotherapy with nivolumab in trichoblastic carcinomas

Trichoblastic carcinoma is a rare malignant cutaneous adnexal tumor with a risk of local invasion and distant metastasis. As of today, there is no consensus for the treatment of locally advanced or metastatic trichoblastic carcinoma. "AcSé Nivolumab" is a multi-center Phase II basket clinical trial (NCT03012581) evaluating the safety and efficacy of nivolumab in several cohorts of rare, advanced cancers. Here we report the results of nivolumab in patients with trichoblastic carcinoma. Of the eleven patients enrolled in the study, five patients had been previously treated by sonic hedgehog inhibitors. The primary endpoint 12-week objective response rate was 9.1% (N = 1/11) with 1 partial response. Six patients who progressed under previous lines of treatment showed stable disease at 12 weeks, reflecting a good control of the disease with nivolumab. Furthermore, 54.5% of the patients (N = 6/11) had their disease under control at 6 months. The 1-year overall survival was 80%, and the median progression-free survival was 8.4 months (95%CI, 5.7 to NA). With 2 responders (2 complete responses), the best response rate to nivolumab at any time was 18.2% (95%CI, 2.3-51.8%). No new safety signals were identified, and adverse events observed herein were previously described and well known with nivolumab monotherapy. These results are promising, suggesting that nivolumab might be an option for patients with advanced trichoblastic carcinomas. Further studies on larger cohorts are necessary to confirm these results and define the role of nivolumab in the treatment of trichoblastic carcinomas.

Trichoblastic carcinoma: a comprehensive review of the literature

Trichoblastic carcinoma is a rare neoplasm thought to arise from malignant degeneration of benign follicular tumors. Its clinical features, optimal treatment, and outcomes remain largely unknown. We performed a comprehensive review of the existing trichoblastic carcinoma literature. PubMed and Google Scholar were searched for keywords related to trichoblastic carcinoma, and additional articles were found in reference lists. Cases with a histopathologic diagnosis of trichoblastic carcinoma were summarized. A total of 93 cases have been described, all in case reports or case series. The average age was 65, with 66.7% of cases in males. A minority of patients had familial tumor syndromes or a history of radiation at the site, and only one was reported to be immunosuppressed. The most common site was the face (48.4%), and the majority developed de novo (87.1%). The clinical presentation was highly variable. Although most cases (82.8%) were successfully treated with surgery alone, a subset of patients had more aggressive disease including local progression or recurrence in five cases, nodal metastases in five cases, and distant metastases in three cases. Trichoblastic carcinoma is a rare malignancy with the potential for aggressive behavior. Further research is needed to better characterize this neoplasm.

[Why is it important to differentiate trichoblastic carcinomas (CT) from basal cell carcinomas (CBC). About 21 cases]

Trichoblastic carcinoma is a rare epithelial malignant epithelial tumor, its diagnosis is difficult and the therapeutic management is non-consensual. This retrospective study, carried out between 2009 and 2015, covered 21 cases and analyzed the diagnostic and therapeutic characteristics of trichoblastic carcinomas. Sex ratio is 2. Trichoblastic carcinoma predominated in the face (65% of cases), particularly in perinasal (30% of cases). Its clinical presentation is in 95% of cases as basal cell carcinoma, which is the first clinical diagnosis evoked. The average size of the tumors was 2.3cm in diameter (from 0.7cm to 15cm). The treatment of these tumors is surgical: the margins retained were on average 0.7cm (0.5cm to 1cm). The first excision was mostly performed under local anesthesia, healthy borders were found in less than 40% of cases, requiring another intervention under general anesthesia with reconstruction by flap or skin graft in nearly 80% of cases. The lymph node metastasis rate was 5%. Three cases of recurrence (17%) occurred between 18 months and 6 years follow-up, despite complete resection. One case recurred three times. These results highlight the difficulty of diagnosing trichoblastic carcinomas, often confused with basal cell carcinomas. Though larger, poorly limited and infiltrating, trichoblastic carcinomas are not really distinguished from basal cell carcinomas. Only the anatomopathological examination of the excision piece make it possible to conclude, the biopsy being most often insufficient. Their local aggressiveness requires a greater margin of excision. The micrographic analysis of Mohs, for the periorificial lesions of the face, would reduce margins, increase their reliability and limit the number of surgical revisions. Finally, the literature reports a high rate of ganglion and visceral metastases (between 9.5 and 11%). Initial search for distal lymph node or metastatic involvement is essential, as well as regular clinical follow-up.