Diagnostic Workup and Management of Squamous Cell Carcinoma of the Upper Extremity

Initial Diagnostic Approach

The American Academy of Dermatology recommends performing a diagnostic biopsy (punch, shave, or excisional) with adequate depth to assess tumor characteristics, followed by risk stratification to determine the need for imaging and lymph node evaluation in patients with cutaneous squamous cell carcinoma (cSCC) of the upper extremity 1, 2
A biopsy should be performed to obtain a specimen with adequate size and depth to reach mid-subcutaneous tissue for accurate diagnosis and staging, considering lesion morphology and location 1, 2
It is essential to provide the pathologist with critical clinical information, including patient age, anatomic location, lesion size, history of immunosuppression, and prior skin cancers, to ensure accurate pathologic assessment 1, 2
The pathologic assessment should include tumor depth, degree of differentiation, presence of aggressive histologic subtypes, perineural invasion, lymphovascular invasion, and invasion of deeper structures 1, 2

High-risk features requiring additional workup include tumor depth >2 mm, perineural or lymphovascular invasion, and tumor diameter ≥5 cm 1, 3
For tumors ≥5 cm in diameter or overlying anatomically complex sites, MRI is recommended to assess tumor extent and involvement of underlying structures, although CT scanning may be substituted if MRI is unavailable 4, 5
Imaging is crucial in the upper extremity to evaluate proximity to neurovascular bundles, tendons, and bone before surgical planning 4, 5

Clinical examination of regional lymph nodes should be performed at initial presentation, and if lymph nodes are clinically palpable, ultrasound-guided fine needle aspiration (FNA) should be obtained to assess for metastatic disease 4, 1
If FNA is inconclusive with persistent clinical suspicion, surgical biopsy should be considered 4
For high-risk tumors, FDG-PET with CT scanning is recommended to evaluate for systemic and lymph node metastases, and CT or MRI of chest, abdomen, and pelvis may be used if PET is unavailable 4

All cases should be presented at a multidisciplinary tumor board to review histology and plan staging and treatment, particularly for upper extremity tumors where functional preservation and reconstruction planning are critical 4, 3
Regular surveillance examinations should be scheduled every 3-6 months for the first 2 years to monitor for local recurrence, regional lymph node involvement, and new primary tumors 5, 3