Sonographic Characteristics of Apocrine Nodular Hidradenoma of the Skin

Abstract

Nodular hidradenomas are benign sweat gland-derived tumors that can produce clinical and dermatoscopic misdiagnoses. Histologically, these tumors can be classified into eccrine and apocrine subtypes. We present the sonographic characteristics of 6 cases of apocrine nodular hidradenomas, which, to our knowledge, is so far the largest series reported. A detailed sonographic analysis included layers, body location, shape, diameters, echostructure patterns, and vascularity. Two sonographic signs not previously reported in these or other common dermatologic lesions were detected: "snow falling" and "fluid-fluid level." The sonographic characteristics of apocrine nodular hidradenomas can support their earlier and more precise diagnosis.

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.…”

“…In our study, we found that all clear cell hidradenomas showed posterior acoustic enhancement, as described in 3 previous case reports . Posterior acoustic enhancement or increased through‐transmission occurs because of the relatively lower attenuation of the sound beam in the imaged lesion compared with the adjacent soft tissues, which results in a hyperechoic appearance of soft tissues deep within the lesion .…”

“…Two of our patients had tumors that showed multiple septa in the anechoic portion. Although that appearance was reported by Wortsman et al, a detailed explanation had not been described. We speculate that the presence of multiple septa may relate to the chronicity of clear cell hidradenoma and be explained by the hemorrhagic contents of the cystic components.…”

“…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.…”

Malignant sweat gland tumor of breast arising in pre-existing benign tumor: A case report

“…Imaging findings of hiradenoma or carcinoma have been rarely reported. Wortsman et al[12] have reported sonographic findings of cystic mass including solid portion, inner septa, internal moving echo mimicking snow falling, and fluid-fluid level with anechoic and hypoechoic fluid. Cho et al[13] have reported a sonographic finding of an oval, well circumscribed complex echoic mass in the subcutaneous layer.…”