What is the diagnosis and ICD-10 (International Classification of Diseases, 10th Revision) code for a patient with an abnormally looking mole that bleeds excessively, potentially indicating a serious skin condition such as melanoma?

Diagnosis and ICD-10 Code for Abnormally Appearing, Bleeding Mole

An abnormally looking mole that bleeds excessively is highly suspicious for melanoma and requires urgent specialist evaluation with complete excisional biopsy—the ICD-10 code depends on the anatomic location (C43.x for confirmed melanoma, D22.x for benign nevus, or D48.5 for uncertain behavior).

Clinical Significance of Bleeding

Bleeding from a pigmented lesion is a critical warning sign that warrants immediate attention 1. According to the British Association of Dermatologists, any new persistent skin lesion that is growing, pigmented, or vascular in appearance—particularly when bleeding—should raise suspicion for melanoma 1. The combination of abnormal appearance and bleeding significantly increases the likelihood of malignant transformation 2.

Diagnostic Terminology

The clinical term for such a lesion depends on its characteristics:

• Atypical mole (dysplastic nevus): Characterized by size >6 mm, color variegation, border irregularity, and pebbled texture, though bleeding is not typical 3, 4
• Melanoma: The most concerning diagnosis when bleeding is present, particularly with ABCDE features (asymmetry, border irregularity, color variability, diameter >6 mm, evolution) 1
• Amelanotic melanoma: A rare subtype (0.4-27.5% of melanomas) that may lack pigmentation and present with bleeding, making diagnosis particularly challenging 5

ICD-10 Coding Structure

The appropriate ICD-10 code depends on anatomic location and diagnostic certainty:

For Confirmed Melanoma (C43.x):

• C43.0: Malignant melanoma of lip
• C43.1: Malignant melanoma of eyelid
• C43.2: Malignant melanoma of ear and external auricular canal
• C43.3: Malignant melanoma of other and unspecified parts of face
• C43.4: Malignant melanoma of scalp and neck
• C43.5: Malignant melanoma of trunk
• C43.6: Malignant melanoma of upper limb
• C43.7: Malignant melanoma of lower limb
• C43.8: Overlapping malignant melanoma of skin
• C43.9: Malignant melanoma of skin, unspecified

For Benign Nevus (D22.x):

Use the same anatomic subdivisions (D22.0 through D22.9) when the lesion is confirmed benign 3

For Uncertain Behavior (D48.5):

Use when the lesion exhibits atypical features but malignancy is not yet confirmed 4

Urgent Management Algorithm

Step 1: Immediate Specialist Referral

Lesions suspicious for melanoma should NOT be removed in primary care 1. The British Association of Dermatologists emphasizes that clinicopathological correlation is vital for diagnostic accuracy, which determines prognosis and adjuvant treatment options 1. Urgent referral to dermatology or a skin cancer multidisciplinary team should occur within 2 weeks 6.

Step 2: Complete Excisional Biopsy

Full-thickness excisional biopsy with 2 mm clinical margin is mandatory 1, 7, 6. This approach includes:

• The entire lesion with surrounding normal skin 1
• A cuff of subcutaneous fat 1
• Elliptical excision with the long axis oriented to facilitate subsequent wide local excision 1

Step 3: Critical Pitfalls to Avoid

Shave biopsies and punch biopsies are absolutely contraindicated 1, 7, 6. These techniques:

• Lead to sampling error and incorrect diagnosis 1
• Make accurate pathological staging impossible 1, 6
• May result in pseudomelanoma appearance if partially removing a benign nevus 1

Incisional biopsy is only acceptable for acral melanoma or lentigo maligna on the face, and only when performed by specialists within a multidisciplinary team 1, 6.

Risk Stratification Features

Clinicians should assess for high-risk characteristics:

• ABCDE criteria: Asymmetry, border irregularity, color variability, diameter >6 mm, evolution over time 1
• "Ugly duckling" sign: Lesions that appear different from other moles on the patient 1
• Bleeding or ulceration: Indicates possible invasion and higher stage disease 1, 2
• Rapid change: Evolution in size, color, or texture over weeks to months 1, 6

High-Risk Populations

Certain patients warrant heightened surveillance 1:

• Fair-skinned individuals over 65 years 1
• Patients with >50 moles or atypical mole phenotype 1, 4
• Personal or family history of melanoma 1, 2
• Giant congenital pigmented nevi 1
• Organ transplant recipients 1

Prognostic Implications

Early detection dramatically impacts survival 2:

• Localized melanoma (stage IA-IIA): 94-98% 10-year survival 2
• Regional disease (stage III): 60-88% 10-year survival 2
• Distant metastatic disease (stage IV): 24-43% 10-year survival 2

The presence of bleeding suggests possible ulceration, which is an adverse prognostic factor requiring consideration for sentinel lymph node biopsy even in thinner lesions 6, 2.