Clear Cell Proliferations of the Skin: A Histopathologic Review

Abstract

Cutaneous clear cell proliferations encompass a heterogenous group of several primary cutaneous neoplasms and metastatic tumors with different histogenesis. Many of these clear cell proliferations may seem strikingly similar under the microscope resulting in challenging diagnosis. In many of these clear cell lesions, the reason for the clear or pale appearance of proliferating cells is unknown, whereas in other ones, this clear cell appearance is due to intracytoplasmic accumulation of glycogen, mucin, or lipid. Artifacts of tissue processing and degenerative phenomenon may also be responsible for the clear cell appearance of proliferating cells. Awareness of the histopathologic findings as well as histochemical and immunohistochemical techniques are crucial to the accurate diagnosis. This review details the histopathologic features of clear cell cutaneous proliferations, classifying them according their type of differentiation and paying special attention to the histopathologic differential diagnosis among them.

Clear-Cell Dermal Duct Tumor: Case Report and Literature Review

“…1–3). Finally, a case of clear-cell dermal duct tumor, included in a recent review published by Zaballos et al 6 and shown in their Figure 15, is the same as case 1 already reported by Rütten et al, 5 shown in their Figure 1.…”

“…Histopathologically, it displayed histologic and immunohistochemical features overlapping to those of cases 4 and 5, reported by Rütten et al 5 , shown in their Figures 2–6; however, unlike these, clear cells were PAS negative, as in other clear cell tumors. 6…”

“…Histopathologically, it displayed histologic and immunohistochemical features overlapping to those of cases 4 and 5, reported by Rütten et al 5 , shown in their Figures 2-6; however, unlike these, clear cells were PAS negative, as in other clear cell tumors. 6 A review of the pertinent literature showed only 13 cases of clear-cell dermal duct tumor, reported as such. 5 Moreover, a clear-cell neoplasm, published by Mehregan et al 7 in 1988, has been reinterpreted as a further example of clear-cell dermal duct tumor.…”

“…Because clear-cell dermal duct tumor is located in the dermis, the histopathologic differential diagnosis may not include clear-cell tumors with an evident intraepidermal component or with a clear continuity with the overlying epidermis or follicular structures, such as clear-cell squamous cell carcinoma, clear-cell porocarcinoma, clear-cell poroma, mammary and extramammary Paget disease, sebaceous adenoma, sebaceous carcinoma, clear-cell basal cell carcinoma, tricholemmoma, tricholemmal carcinoma, and clear-cell trichoblastoma. 6 Conversely, epithelial clear-cell neoplastic lesions located in the dermis can show a close resemblance to clear-cell dermal duct tumors and the differential diagnosis may be more difficult. Clear-cell syringoma shows smaller islands with characteristic “tadpole” extensions; ductal structures, lined by a double layer of cuboidal cells; and more copious sclerotic stroma.…”

Primary Cutaneous Malignant Perivascular Epithelioïd Cell Tumor (PEComa): Case Report With Review of the Literature

“…This includes metastatic clear cell renal carcinoma, sebaceous carcinoma, clear-cell sarcoma, balloon-cell melanoma, balloon-cell nevi, clear cell hidradenoma, clear cell xanthoma, and the list is long. 11 For a precise diagnosis, a wide immunohistochemical analysis with a panel of multiple antibodies is required.…”