Basaloid Squamous Cell Carcinoma on the Skin of the Hand

Im ag es Basaloid squamous cell carcinoma (BSCC), an uncommon tumor with a predilection for the upper aerodigestive tract, is considered a distinct variant of squamous carcinoma due to its unique histological features and aggressive clinical behavior [1,2]. To the best of our knowledge, BSCC with a primary origin in the skin is extremely rare, although metastatic deposits of this type of cancer have been reported on the skin [3,4]. In this report, we present an unusual case of primary BSCC of the skin of the hand. An 89-year-old female presented with an exophytic mass on the dorsum of the proximal phalanx of the right third finger that had exhibited rapid growth. The mass was grossly measured to be approximately 1.5 cm × 1.5 cm, with irregularly protruding and ulcerative features (Fig. 1). A punch biopsy was performed by a dermatologist, and the pathology report found malignancy with skin surface necrosis and multifocal tumor cell necrosis. Chest computed tomography and positron emission tomography were performed as part of a metastatic work-up, but no evidence of metastasis was observed. A wide excision was made, with a 1.5-cm peripheral margin, and the sheath of the extensor tendon was removed to ensure the complete removal of the tumor along the deep margin (Fig. 2). All frozen biopsies from the surgical margin were found to be negative, and a venous free flap with a 6-cm × 3.5-cm skin paddle was harvested from the ipsilateral forearm. One proximal vein was anastomosed to the distal end of the digital artery,