Atypical papular mucinosis with thyroid cancer: comparison of isotretinoin and erbium:YAG laser treatment.

Papular mucinosis (PM), or lichen myxoedematosus, is a rare skin disorder characterized by mucin deposition in the dermis, resulting in papules and nodules. It can present as scleromyxoedema, often with systemic complications, or localized PM, which typically follows a benign course. Atypical cases may present with unique features. We present an atypical case of PM in a 23-year-old woman with concurrent Hashimoto thyroiditis and papillary thyroid carcinoma. The patient presented with numerous progressive papules on her chest and abdomen, alongside systemic symptoms, including fatigue and weight loss. Diagnosis was confirmed through skin biopsy revealing mucin deposition. Initial treatment with isotretinoin yielded minimal improvement. However, significant improvement was observed following ablative erbium:YAG laser therapy, resulting in a marked reduction of lesions with no recurrence. This case highlights the classification of PM and demonstrates the potential effectiveness of laser therapy as a treatment option for this challenging condition.