Aggressive secondary squamous carcinoma appeared during BRAF inhibitor targeted therapy

From Skin and Allergy News, 26 February 2014:

A woman undergoing BRAF inhibitor targeted therapy for advanced melanoma has presented with invasive spindle cell squamous carcinoma masquerading as a secondary cutaneous squamous cell carcinoma, highlighting the importance of histologic evaluation of these lesions.

“Secondary cutaneous squamous cell carcinomas (cSCCs) are adverse effects of BRAF inhibitor targeted therapy for advanced melanoma,” wrote Dr. Daniel N. Cohen and his associates online Feb. 26 in JAMA Dermatology.

The most commonly seen histologic type of secondary cutaneous squamous cell carcinomas is keratoacanthoma-like cSCC (cSCC-KA), which is thought to have a low risk of metastasis or recurrence, said lead author Dr. Cohen of the Vanderbilt University Medical Center, Nashville, Tenn.

In this case report, however, a woman in her 50s with BRAF-mutant metastatic melanoma developed more than 100 new cutaneous squamous proliferations across her face, trunk, and extremities within 4 weeks of starting treatment with the BRAF inhibitor dabrafenib as part of a clinical trial, with some lesions appearing to be a more aggressive type upon analysis.

The lesions began as acrochordons on her face and extremities, as well as new nevi on her torso and axilla. She also developed fever, chills, and fatigue and had enlarging, tender, and bleeding lesions on her trunk and extremities.

Seven large, tender, and indurated lesions were removed using a deep scoop shave biopsy, revealing a biphasic malignant growth pattern (JAMA Dermatology 2014 Feb 26 [doi:10.1001/jamadermatol.2013.7784]). Read more.