Reticulated acanthoma with sebaceous differentiation: another sebaceous neoplasm associated with Muir-Torre syndrome?

Seborrheic Keratosis With Sebaceous Differentiation, a Series of 8 Cases and Critical Review of the Literature

ABSTRACT

Seborrheic keratosis with sebaceous differentiation (SKSD) can sometimes raise uncertainty, confuse with other even malignant entities, and lead to overestimation of this harmless variant. Retrospective analysis of the cases diagnosed as SKSD and a search of the pertaining literature were conducted. Eight cases of SKSD were found. Histologically, these lesions show a flat to plate-like outgrowth of basaloid cells with solitary or clustered sebocytes at the bottom of the rete ridges and variable sebaceous ducts with luminal cuticula. The lesions differed in the outgrowth subpattern: flat/macular, acanthotic, or reticulated. No association was found with Muir-Torre syndrome, and no malignant transformation was seen in these lesions. Literature search revealed confusingly designated lesions that simply represented SKSD. SKSD can show several growth patterns as classic SK. This entity is either underreported or even underrecognized. This entity is benign; however, according to the literature, exclusion of an associating Muir-Torre syndrome should be warranted. The published literature about this lesion is confusing and inconsistent. We suggest the avoidance of confusing terminology and particularly the terminus epithelioma for such lesions.

Sebaceous lesions of the skin

Sebaceous differentiation is commonly seen in cutaneous neoplasms, both in the context of lesions showing predominantly sebaceous differentiation (e.g., sebaceous adenoma, sebaceoma and sebaceous carcinoma), or as more focal sebaceous components in neoplasms with other primary lines of differentiation. Sebaceous changes can also be a component of benign cystic lesions or epidermal tumours, and sebaceous hyperplasia is commonly encountered. This review is intended to provide an overview of the cutaneous lesions with sebaceous differentiation, with a particular emphasis on facilitating histological diagnosis of neoplasms. In addition, the role of immunohistochemical studies is outlined, as well as the evaluation of potential cases of Muir-Torre syndrome.

Superficial epithelioma with sebaceous differentiation: a case report with literature review

Superficial epithelioma with sebaceous differentiation is the original name for a rare benign tumor that lacks consensus in the literature, both in nomenclature and in diagnostic criteria. We report the case of a 68-year-old male with a white papule on the left lower eyelid, fully excised. On histology, the lesion was a superficial, lobulated, plate-like epithelial proliferation, with small mature clusters of sebocytes and ductal structures. Mismatch repair proteins MLH-1, MSH-2, MSH-6, and PMS-2 were retained in the immunohistochemistry study. We reviewed the literature and added our case, which we believe contributes to better characterization of superficial epithelioma with sebaceous differentiation. It usually presents as a solitary papule or nodule on the face of middle-aged males. Histologically, besides the hallmark of a superficial plate-like epithelial proliferation, some variations are occasionally reported: the presence of randomly scattered keratin-filled cysts, squamous eddies, minimal peripheral palisading, marked verruciform architecture, and a reticulated pattern with elongated strands of keratinocytes. The mitotic activity can be high, but no cytological atypia or necrosis is seen. If properly removed, there is no evidence of local recurrence or distant spread. The association with Muir-Torre syndrome remains unclear.

Reticulated acanthoma with sebaceous differentiation mimicking melanoma

Reticulated acanthoma with sebaceous differentiation (RASD) is a rare, benign cutaneous tumor with peculiar histopathologic characteristics [1]. RASD had been described under various synonyms such as superficial epithelioma with sebaceous differentiation, sebocrine adenoma, poroma with sebaceous differentiation, and seborrheic keratosis with sebaceous differentiation [2]. Clinical differential diagnosis of RASD includes cutaneous superficial epithelial neoplasia such as Bowen’s disease, superficial basal cell carcinoma (BCC) and intraepidermal eccrine poroma [1]. We report the first case of RASD mimicking both clinically and dermoscopically a melanoma.