Squamous Cell Carcinoma
The most likely diagnosis is squamous cell carcinoma (SCC), given the 1.5 cm erythematous nodule with central ulceration and crust on a sun-exposed area (cheek), firm consistency on palpation, 5-month progressive growth, intermittent itching, bleeding with trauma, and outdoor exposure history. 1, 2
Clinical Features Supporting SCC Diagnosis
The presentation demonstrates classic high-risk SCC characteristics:
- Nodular morphology with central ulceration and crust on the cheek represents a typical presentation of invasive SCC, particularly the nodular subtype which tends to be more aggressive 2, 3
- Size >1.5 cm places this in the higher-risk category, as tumors >2 cm are associated with increased metastatic potential 2, 4
- Firm consistency on palpation suggests deeper dermal involvement, indicating potential infiltrative growth pattern 1, 2
- Progressive growth over 5 months with bleeding upon trauma aligns with SCC behavior rather than benign lesions 5, 6
- Location on the cheek (temple/ear/lip area) is considered a high-risk anatomic site for SCC 2, 4
- Outdoor exposure history provides the chronic UV radiation exposure that is the primary risk factor for SCC development 6
Why Other Diagnoses Are Less Likely
Actinic keratosis presents as rough, scaly patches rather than a 1.5 cm nodule with central ulceration and would not demonstrate this degree of firmness or progressive growth 5
Pyogenic granuloma typically develops rapidly over days to weeks (not 5 months), appears as a friable, bleeding papule without the firm consistency or raised border described here 3
Seborrheic keratosis presents as a "stuck-on" waxy or verrucous plaque without ulceration, bleeding only with trauma, or the firm infiltrative quality on palpation 3, 5
Basal cell carcinoma (BCC) remains in the differential but is less likely because: while BCC can present as a nodule with central ulceration (nodular BCC), the firm consistency suggesting deeper invasion and the 5-month progressive growth pattern are more characteristic of SCC's more aggressive behavior 1, 2
Immediate Diagnostic Steps Required
Perform complete surgical excision with histopathologic examination rather than punch biopsy, as complete tissue assessment is necessary to evaluate depth of invasion, differentiation grade, perineural invasion, and margin adequacy 1, 2
Obtain lymph node ultrasound of the regional basin (preauricular, parotid, and cervical nodes for cheek lesions) given the high-risk features: size >1.5 cm, firm consistency suggesting depth >6 mm, and high-risk facial location 2, 4
Surgical margins should be 10 mm for this high-risk tumor based on size, location, and clinical features suggesting depth and potential aggressive histology 2
High-Risk Features to Assess on Histopathology
The pathology report must specifically document:
- Tumor thickness (>6 mm indicates high risk) 2, 4
- Depth of invasion (invasion beyond subcutaneous fat significantly worsens prognosis) 2, 4
- Histologic grade of differentiation (poor differentiation increases metastatic risk) 2, 4
- Perineural invasion (major risk factor for recurrence and metastasis) 2, 4
- Desmoplasia and infiltrative growth pattern 4
- Margin status (positive margins require re-excision) 2
Critical Pitfall to Avoid
Do not perform a small punch biopsy for suspected invasive SCC, as this prevents accurate assessment of tumor depth, which is the single most important prognostic factor for staging and determining need for lymph node evaluation 2, 4