Large, linear pigmentation anomaly: an unusual dyspigmentation case

Area of Science:

• Dermatology
• Genetics
• Oncology

Background:

• Segmental pigmentation anomalies encompass segmental pigmentation disorder (SPD) complex and café-au-lait macules (CALMs).
• SPD is rare, while CALMs are common and can indicate underlying genetic conditions, especially with multiple lesions or other abnormalities.
• Segmental CALMs warrant consideration of segmental neurofibromatosis (type V) in differential diagnoses.

Observation:

• A 48-year-old woman with a history of malignant melanoma presented with a large, congenital, linear hyperpigmented patch on her shoulder and arm.
• The differential diagnosis included café-au-lait macule (CALM) versus hypermelanosis, a subtype of SPD.
• A family history of similar lesions and personal/family history of melanoma and cancers prompted genetic testing.

Findings:

• Hereditary cancer panel testing revealed a genetic variant of uncertain significance.
• The patient's presentation highlights a rare dyspigmentation disorder.

Implications:

• This case raises questions about a potential association between rare dyspigmentation disorders like SPD and melanoma.
• Further research is warranted to understand the genetic underpinnings and clinical significance of such associations.
• Highlights the importance of considering rare genetic skin conditions in patients with a history of cancer.