Syringocystadenocarcinoma Papilliferum In Situ–Like Changes in Extramammary Paget Disease: A Report of 11 Cases

Abstract

The authors report 11 cases of extramammary Paget disease (EMPD), all of which also demonstrated a combination of histological changes highly reminiscent of syringocystadenocarcinoma papilliferum in situ. In addition to the classical features of EMPD, characterized by the intraepidermal spread of individually dispersed neoplastic cells with ample cytoplasm, many of which contained mucin, there were areas of acanthosis with the substitution of spinous layer keratinocytes by neoplastic cells, whereas the native basal cell layer was intact. In addition to acanthosis (and sometimes papillomatosis), the dermal papillae showed a prominent infiltrate of plasma cells, completing the resemblance to syringocystadenocarcinoma papilliferum in situ; this similarity was further enhanced in 2 cases, which showed conspicuous gland formation. One additional case showed multifocal dermal proliferations compatible with eccrine syringofibroadenoma (syringofibroadenomatous hyperplasia). The changes described herein seem to be relatively rare in EMPD, and they can represent a diagnostic pitfall, as evidenced by 2 cases that were originally misinterpreted as syringocystadenocarcinoma papilliferum in situ. Clinically, these microscopic changes sometimes corresponded to nodular lesions, which were specifically noted to have a papillated erosive surface.

Anogenital syringocystadenocarcinoma papilliferum in situ or anaplastic extramammary Paget disease? A unifying concept and review of the literature

“…Histopathologically, the lesions exhibited “cleft like” acantholysis with full‐thickness atypia, mimicking acantholytic squamous cell carcinoma in situ 16 . Two additional cases of PD with similar features were reported in 2009, 17 and since that time similar findings have been reported in cases of EMPD under various descriptions, including acantholytic anaplastic EMPD, EMPD mimicking acantholytic squamous cell carcinoma in situ, and syringocystadenocarcinoma papilliferum in situ (SCACPIS)‐like change 16‐29 . In addition to the findings of these atypical cases of EMPD with full‐thickness bowenoid atypia and acantholysis, our case also notably overlaps with prior descriptions of SCACPIS, including prominent glandular formation and involvement of adnexal structures with papillations and a plasma‐cell‐rich infiltrate.…”

“…SCACPIS is an extremely rare form of cutaneous adenocarcinoma in situ with exceedingly rare reports in the literature 22 . The lesions typically have a warty or exophytic appearance and present in the head and neck region, usually arising from pre‐existing syringocystadenoma (SCP) 18‐23 . Histopathologically, the lesions entirely replace the epidermis and can extend down the adnexa.…”

Current Diagnosis and Treatment Options for Cutaneous Adnexal Neoplasms with Apocrine and Eccrine Differentiation

“…GCDFP-15 may be expressed in the in situ areas and components of invasive adenocarcinoma. Other immunohistochemical markers for epithelial cells include EMA, CK7, and CAM5.2 [ 164 , 165 , 167 ]. In the limited number of cases, an extramammary Paget disease should be excluded since lesions suggesting SCACP in situ may show pagetoid spread [ 168 ].…”

Spectrum of Changes in Anogenital Mammary-like Glands in Primary Extramammary (Anogenital) Paget Disease and Their Possible Role in the Pathogenesis of the Disease

“…All included patients were the subjects of previous publications addressing various other clinicopathologic aspects of AGMLG and EMPD. 7,22,[27][28][29]…”