Granular cell tumors are uncommon neoplasms of neural origin that may involve the skin and often present with nonspecific clinical features, making diagnosis challenging. Cutaneous granular cell tumors rarely exhibit overlying hypertrichosis, a finding that may obscure their clinical recognition. In this report, we describe a rare case of a primary cutaneous granular cell tumor with prominent overlying terminal hair growth in an adult patient. A 27-year-old woman presented with a slowly enlarging, firm, pigmented plaque on the upper back associated with pruritus and increased hair growth. Histopathologic examination revealed sheets of large polygonal cells with abundant granular eosinophilic cytoplasm, and immunohistochemical staining was positive for S100, SOX10, CD68, and calretinin, confirming the diagnosis. The lesion was completely excised with no evidence of malignancy. To our knowledge, this represents the second reported instance of a cutaneous granular cell tumor associated with hypertrichosis and the first described in an adult. It underscores the importance of clinicopathologic correlation in evaluating unusual cutaneous lesions and expands the spectrum of recognized presentations of cutaneous granular cell tumors.

Lichenoid drug eruption (LDE) is an uncommon adverse reaction that can be clinically indistinguishable from idiopathic lichen planus (LP). We report a 63-year-old woman who developed a diffuse pruritic papular eruption with oral mucosal involvement two weeks after initiating letrozole for breast cancer. Histopathology revealed lichenoid interface dermatitis with scattered eosinophils extending into the deep subcutaneous tissue, supporting a drug-induced process. Due to the necessity of endocrine therapy, she was managed with high-potency topical corticosteroids and tacrolimus. Upon histologic confirmation, letrozole was replaced with exemestane, leading to a 90% improvement without recurrence. This case emphasizes the importance of clinicopathologic correlation and multidisciplinary coordination to maintain essential oncologic treatment while managing cutaneous toxicity.