A giant trichoblastic carcinoma

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.

Don't Judge a Tumor by Its Biopsy!

Trichoblastomas (TBs) are extremely rare, benign hair germ tumors that can mimic basal cell carcinoma (BCC). They usually arise on the head or neck and have a potential for malignant transformation, albeit it is rare. We report a case of giant TB on the forehead of a 75-year-old otherwise healthy woman. Since the age of 20 she reported a bulge on her forehead, in which a superficial-looking wound had now developed. Initially a dermatologist biopsied the tumor suspecting a BCC, which the histological analyses confirmed. The patient was then referred to the Department of Plastic Surgery for complete excision of the carcinoma, including the large frontal bulge. Surprisingly, the concluding pathology report changed the diagnosis from a BCC to a TB. Current management of most skin lesions relies on the histopathological subtype of a single punch biopsy. Many benign and malignant dermatological entities may mimic BCC, and therefore misdiagnosis can lead to either unnecessary excision or delayed treatment of metastatic disease. Mimics may include various types of nonneoplastic processes, benign adnexal tumors, including TB, or cutaneous carcinomas with basaloid features. A single punch biopsy is not always adequate in making the correct diagnosis. Although it is considered the gold standard, the clinical assessment is just as important. Due to its potential for malignant transformation, it is recommended to excise TB with negative margins.