A male patient presented with a 0.3 cm nodule on the left nasolabial fold. It was excised, and a pathological examination was done. What is the diagnosis? [image]

Correct Answer: B. Basal cell carcinoma

Basal cell carcinoma (BCC) is the most common malignancy of the skin in India, accounting for ~80% of non-melanoma skin cancers. The nasolabial fold is a classic site of predilection due to chronic sun exposure and the embryological origin of this region. On histopathology, BCC presents with characteristic basaloid nests of cells arising from the basal layer of the epidermis, often with a peripheral palisade arrangement and retraction artifact around the nests (creating a "halo" effect). The tumor typically shows a pearly, translucent appearance clinically with rolled edges and central ulceration (rodent ulcer). At 0.3 cm, this is a small, early lesion—exactly the size at which BCC is most commonly detected and excised in outpatient settings across Indian dermatology and plastic surgery practices. The nasolabial fold location, small size, and histological findings of basaloid proliferation with peripheral palisading are pathognomonic for BCC. Unlike SCC, BCC rarely metastasizes and has an excellent prognosis with surgical excision alone, making early diagnosis critical for optimal outcomes.

Why the other options are wrong

A. Squamous cell carcinoma — SCC typically presents as a larger, more infiltrative lesion with keratinization and horn formation; histologically shows keratin pearls and intercellular bridges rather than basaloid nests. While SCC can occur on the face, it is less common than BCC in the nasolabial fold region and usually appears more erythematous and scaly. The small size (0.3 cm) and pearly appearance favor BCC over SCC. C. Melanoma — Melanoma would show atypical melanocytes with increased mitotic activity, nuclear pleomorphism, and melanin production on histology. Clinically, melanoma presents with asymmetry, irregular borders, color variation (ABCDE criteria), and typically larger size at presentation. The nasolabial fold is not a common site for melanoma, and the small, pearly nodule described is inconsistent with melanoma's typical presentation. D. Nevus — A benign nevus would show well-circumscribed nests of mature melanocytes with symmetry and uniform appearance, lacking the basaloid proliferation and peripheral palisading seen in BCC. Nevi are typically stable, non-ulcerating lesions without the pearly, translucent quality or rolled edges characteristic of BCC. The clinical presentation and histology clearly indicate malignancy, not a benign lesion.

High-Yield Facts

Mnemonics

BCC vs SCC: PEARL vs HORN BCC = PEARLy, translucent, rolled edges, ulcerated. SCC = HORNy, keratinized, infiltrative, keratin pearls. Use when differentiating face lesions. BCC Histology: BASALOID PALISADE Basaloid nests, Artifact (retraction), Small cells, Arrangement (peripheral palisade). Recall when reviewing pathology slides.

NBE Trap

NBE may pair small facial nodules with melanoma or SCC to test whether students reflexively associate "skin cancer" with "melanoma" or "larger lesions." The key discriminator is the nasolabial fold location + pearly appearance + small size, which are classic for BCC, not the more aggressive malignancies.

Clinical Pearl

In Indian outpatient plastic surgery clinics, small pearly nodules on the nasolabial fold are excised as routine day-care procedures with excellent cosmetic outcomes. Early recognition and excision prevent progression to larger, more disfiguring lesions—critical in a country with high sun exposure and limited access to advanced reconstructive surgery in many regions.

_Reference: Bailey & Love Ch. 43 (Skin Lesions); Robbins Ch. 25 (Skin Pathology); OP Ghai Ch. 12 (Dermatology)_