Malignant Nodular Hidradenoma of the Fingertip: A Case Report

Malignant nodular hidradenoma (MNH) is an infrequent, highly malignant tumor derived from eccrine sweat glands. MNH usually occurs on the scalp, trunk, and proximal extremities, and rarely on the hand. A 55-year-old male patient visited clinics with a gradually enlarging painless mass at fingertip. It begins a year ago. Recently, it has grown rapidly and starts ulceration, and bleeding over the past 3 weeks. According to the biopsy report, it has focal necrosis, atypia, atypical mitoses, and nuclear pleomorphism suggested that the mass was MNH. After histological diagnosis, tiny bone erosion was observed in the re-read radiographic finding. For the oncologic evaluation, the patient was transferred to the cancer center. Radical amputation was performed to the residual tumor that might remain based on re-reading of radiographs. MNH of the finger is especially difficult to the diagnosis given its rarity and variable histology. When ulcerative skin lesion and radiographic bone erosion are observed, one should suspect malignancy and makes out a proper therapeutic plan after histologic biopsy.

Rarely seen accelerated progression of hidradenitis suppurativa

Malignant nodular hidradenoma, also known as Malignant Hidradenocarcinoma (MHA), is a rare tumor of sweat glands that accounts for less than 0.001% of all tumors [1-3,14]. Although it typically arises de-novo, MHA rarely progresses from hidradenitis suppurativa (HS), a disorder of apocrine glands characterized by chronic inflammation [5,6,9]. HS is due to recurrent follicular occlusion leading to painful debilitating cutaneous/subcutaneous abscesses requiring drainage [5,6,9]. Common sites include axillary, anogenital and inguinal regions [5,6,9]. The worldwide prevalence of HS is 1%-4% [5,6]. Incidence of all eccrine carcinomas is ~ 6% [14]. Risk-factors include family history, obesity, and smoking [5,6,9]. Severe complications associated with HS are squamous cell carcinoma and adenocarcinoma [2,6]. MHA progression is extremely aggressive with 60% cases having metastatic spread within the first 2 years of diagnosis [14].