Giant clear cell hidradenoma of the knee

Abstract

Hidradenomas, also referred to as nodular hidradenomas or clear cell hidradenomas (CCH), are benign cutaneous eccrine tumors usually 2-3 cm in dimension. Hidradenomas are relatively common; however, giant forms are rare. We report a case of an 8.0 x 6.0 x 3.0 cm clear cell hidradenoma of the left knee in a 43-year-old man. The tumor was mobile, located above the patellar tendon and was without bony involvement on imaging studies. Grossly, the resected tumor was unencapsulated and tan, with a solid and cystic cut surface showing papillary excrescences on the cyst wall. Microscopically, the tumor cells showed an infiltrative growth pattern at the periphery, however, the tumor cytology was bland and no necrosis or mitoses were identified. The overlying dermis contained hemosiderin pigment deposition and infiltration with eosinophils. Immunohistochemically, tumor cells were positive for cytokeratin, CAM5.2, p53, carcino-embryonic antigen (CEA) and epithelial membrane antigen (EMA), and negative for CD10 and Ki-67. The cytological features of hidradenomas can present diagnostic challenges, as other 'clear cell' tumors such as metastatic renal cell carcinoma should be considered. Immunohistochemical studies and differential diagnoses are discussed.

Clear Cell Hidradenoma: Characteristic Imaging Features on Ultrasonography, Computed Tomography, and Magnetic Resonance Imaging

“…Clear cell hidradenoma is classified as a cutaneous tumor originating from skin appendages. However, all of the clear cell hidradenomas in our study were primarily located in the subcutaneous fat layer with or without involvement of the dermal layer and were similar to those in previously published reports . This finding could be attributed to the relatively strong and elastic nature of the dermal layer compared with that of the subcutaneous fat layer, as was another sweat gland tumor reported by Jin et al Furthermore, there was no extension of the lesion to the epidermis or muscular structures in any case.…”

“…These small but palpable superficial lesions rarely require radiologic evaluation and are most often diagnosed and treated by excision. There are few reports on the findings of clear cell hidradenoma on ultrasonography (US), computed tomography (CT), and magnetic resonance imaging (MRI) . The purpose of this retrospective study was to analyze and describe the imaging features of clear cell hidradenoma seen on US, CT, and MRI.…”

A giant benign clear cell hidradenoma on the anterior trunk

“…5,6 There is a single case report in the literature, in which the patient had a benign CCH in unusual size. 7 Most of the tumors reported in the literature are small round red or skin colored nodules or sometimes subcutaneous lesions are misdiagnosed as epidermoid cysts. 8 Ulcer formation is also rare.…”

Giant Hidradenoma of Limbs: A Report of Two Pediatric Cases

“…The stroma is sclerotic or richly vascularized with ectasic vessels. The immunohistochemical study shows positivity to cytokeratin, and the P53 protein as well as CD10 and KI67 negativity for clear cell hidradenomas and makes it possible to distinguish between the two forms [8]. The prognosis of hidradenoma is often good but malignant transformation into hidradenosarcoma is possible, this risk is increased after the age of 50 years.…”

“…Overall survival is 15 to 45 months and the progression without recurrence at 5 years is evaluated at 30% [16,17]. The determination of the carcinoembryonic antigen (ACE) is used to detect local recurrent sub-clinical [8].…”