Question:
A patient has an irregular black pigmented lesion on the heel/sole suspicious for acral melanoma. The most appropriate confirmatory investigation is:
A patient has an irregular black pigmented lesion on the heel/sole suspicious for acral melanoma. The most appropriate confirmatory investigation is:
Show Hint
Pigmented lesion suspicious of melanoma - only tissue (biopsy) confirms it.
Updated On: Jun 25, 2026
- Excisional / full-thickness biopsy with histopathology
- KOH mount / Gram stain
- Tzanck smear
- Wood's lamp examination
Show Solution
Verified By Collegedunia
The Correct Option is A
Solution and Explanation
Step 1: A new or changing black pigmented lesion on the heel/sole in an adult must be treated as possible acral lentiginous melanoma until proven otherwise - the most common melanoma subtype in dark-skinned and Asian populations.
Step 2: Definitive diagnosis of any suspected melanoma requires histopathology. The gold standard is an excisional (full-thickness) biopsy that allows measurement of Breslow thickness, which guides staging and management. (A full-thickness incisional/punch biopsy of the thickest area is acceptable when the lesion is large.)
Step 3: Why the others are wrong - KOH/Gram stain detects fungi/bacteria and is useless for a pigmented neoplasm. Tzanck smear looks for multinucleated giant cells in vesicular viral lesions (herpes/varicella) or pemphigus, not melanoma. Wood's lamp highlights pigment depth and some infections but cannot diagnose malignancy.
Key fact: Suspected acral melanoma to biopsy with histopathology for diagnosis and Breslow thickness.
Step 2: Definitive diagnosis of any suspected melanoma requires histopathology. The gold standard is an excisional (full-thickness) biopsy that allows measurement of Breslow thickness, which guides staging and management. (A full-thickness incisional/punch biopsy of the thickest area is acceptable when the lesion is large.)
Step 3: Why the others are wrong - KOH/Gram stain detects fungi/bacteria and is useless for a pigmented neoplasm. Tzanck smear looks for multinucleated giant cells in vesicular viral lesions (herpes/varicella) or pemphigus, not melanoma. Wood's lamp highlights pigment depth and some infections but cannot diagnose malignancy.
Key fact: Suspected acral melanoma to biopsy with histopathology for diagnosis and Breslow thickness.
Was this answer helpful?
0
0
Top INI CET Dermatology Questions
- An infant presents with intensely itchy erythematous papules and vesicles distributed over the palms, soles and umbilical region, with similar lesions in family members. The most likely diagnosis is:
- Match the clinical sign with the correct dermatological condition and select the correctly matched pair(s):
(i) Positive Nikolsky sign - Pemphigus vulgaris
(ii) Negative/absent Nikolsky sign - Bullous pemphigoid
(iii) Pseudo-Nikolsky sign - Stevens-Johnson syndrome / Toxic epidermal necrolysis
(iv) Cerebriform tongue - Pemphigus vegetans - A patient presents with a black pigmented lesion on the heel/sole (as shown). Which is the investigation of choice to establish the diagnosis?
- A patient presents with painful grouped vesicles over the penile/genital region associated with fever and malaise. What is the most likely causative organism?
- A 2-day-old neonate presents with blistering/erosive skin lesions over the face and abdomen. There is no fever and no mucosal involvement. The mother has a history of an autoimmune blistering disorder. What is the most likely diagnosis?
View More Questions
Top INI CET Questions
- Which of the following is the most common cause of acute pancreatitis?
- Which of the following conditions is most commonly associated with hypoparathyroidism?
- The drug of choice for treating acute gout flare is:
- Which of the following bacteria is the most common cause of community-acquired pneumonia?
- Which of the following is the hallmark of Type 1 Diabetes mellitus?
View More Questions