Basal Cell Carcinoma (BCC)

• Most common cutaneous cancer
• Transplant patients with 10-fold higher risk
• Multiple variants with specific features
  • Superficial BCC: may present as a pink thin plaque with pearly border, ± scale, ± pigment, commonly seen on trunk or limb; histology shows many superficial buds of basaloid cells limited to superficial dermis, peripheral palisading of nuclei
  • Nodular BCC: most common; translucent papule or nodule with overlying telangiectasias. ± ulceration, ± pigment (small areas of brown pigment), over time borders often become rolled and pearly with central ulceration (‘rodent ulcer’); histology shows large islands of basaloid keratinocytes with peripheral palisading within dermis, fibromyxoid stroma, stromal retraction around tumor islands, ± necrosis within large tumor islands forming cystic areas
  • Morpheaform BCC: indurated firm plaque with ill-defined borders resembling a scar, aggressive growth pattern; histology with strands of basaloid keratinocytes within fibrotic stroma
  • Metatypical (basosquamous) BCC: features of both BCC and SCC
  • Micronodular: histology with small tumor islands (smaller than nodular BCC) within fibrous stroma
  • Adenoid BCC: histology shows pseudoglandular pattern with mucin within basaloid aggregates
  • Cystic BCC: gray-blue cystic papule or nodule with clear fluid in center; histology shows pools of mucin seen histologically within center of tumor
  • Fibroepithelioma of Pinkus: rare variant appearing as pink plaque or smooth nodule on lower back; histology with thin anastomosing cords of basaloid cells in fibrous stroma arising from epidermis
• Rarely metastasizes (lymph nodes and lung)
• Treatment: topical imiquimod (for superficial BCCs), surgical excision with margins, Mohs micrographic surgery, curettage and electrodessication, radiotherapy

Figure 5.8 A: Keratoacanthoma (Courtesy of Dr. Paul Getz) B: Keratoacanthoma C: Keratoacanthoma

Figure 5.9 A: Morpheaform BCC B: Nodular BCC C: Ulcerated BCC