Syringocystadenocarcinoma Papilliferum In Situ, a Variant of Cutaneous Adenocarcinoma In Situ: A Case Report With Literature Review

Syringocystadenocarcinoma papilliferum: a systematic review of clinical characteristics, reappraisal of associations, diagnostic pitfalls and management challenges

Syringocystadenocarcinoma papilliferum (SCACP) is a rare and aggressive malignant adnexal tumor originating from apocrine or pluripotent appendageal glands, often associated with a preceding syringocystadenoma papilliferum (SCAP) or nevus sebaceus (NS). This systematic review rigorously examines SCACP through an analysis of 78 cases documented between 1980 and 2024. The study aims to provide a comprehensive review of the clinical manifestations, diagnosis, treatment modalities, and outcomes associated with SCACP, while also reappraising its associations, particularly with NS. SCACP predominantly affects older adults, with an average age of 66.3 years and a slight male predominance, commonly presenting as ulcerated nodules or plaques on the scalp. This review highlights the aggressive nature of SCACP, evidenced by significant rates of metastasis and recurrence. Treatment is primarily surgical, with Mohs micrographic surgery offering potential benefits in terms of margin control and cosmetic outcomes. The association of SCACP with NS is critically evaluated, suggesting a complex etiopathogenesis and underscoring the importance of recognizing this association for timely diagnosis and management. Our review also briefly discusses potential pitfalls faced by clinicians in the diagnosis of SCACP. Our findings emphasize the need for standardized treatment protocols and further research into targeted therapies to improve patient outcomes in SCACP.

Molecular Profiling of Syringocystadenocarcinoma Papilliferum Reveals RAS-Activating Mutations

CONTEXT.—

Syringocystadenocarcinoma papilliferum (SCACP) is a rare adnexal carcinoma and the malignant counterpart of syringocystadenoma papilliferum (SCAP), which is commonly located on the head and neck and may arise in association with a nevus sebaceus. RAS mutations have been identified in both SCAP and nevus sebaceus.

OBJECTIVE.—

To evaluate the clinicopathologic and molecular features of SCACPs, which have not been previously explored.

DESIGN.—

We obtained 11 SCACPs from 6 institutions and reviewed the clinicopathologic features. We also performed molecular profiling using next-generation sequencing.

RESULTS.—

The cohort comprised 6 women and 5 men with ages ranging from 29 to 96 years (mean, 73.6 years). The neoplasms occurred on the head and neck (n = 8; 73%) and extremities (n = 3; 27%). Three tumors possibly arose in a nevus sebaceus. A total of 4 cases showed at least carcinoma in situ (adenocarcinoma, n = 3; squamous cell carcinoma [SCC], n = 1), and 7 cases were invasive (SCC, n = 5; mixed adenocarcinoma + SCC, n = 2). A total of 8 of 11 cases (73%) had hot spot mutations consisting of HRAS (n = 4), KRAS (n = 1), BRAF (n = 1), TP53 (n = 4), ATM (n = 2), FLT3 (n = 1), CDKN2A (n = 1), and PTEN (n = 1). All 4 cases with HRAS mutations occurred on the head and neck, whereas the KRAS mutation occurred on the extremity.

CONCLUSIONS.—

RAS-activating mutations were detected in 50% of the cases, of which most (80%) involved HRAS and occurred on the head and neck, which shows overlapping features with SCAP, supporting that a subset may arise as a result of malignant transformation and likely an early oncogenic event.

Syringocystadenocarcinoma Papilliferum in a Fifteen-Year-Old Girl: A Case Report and Review of the Literature

Syringocystadenocarcinoma papilliferum (SCACP) is a rare malignant neoplasm arising from adnexal tissues and is the malignant complement to the benign neoplasm syringocystadenoma papilliferum (SCAP). SCACP lesions appear as raised nodules or inflammatory plaques and can be associated with SCAP or nevus sebaceous. There have been fewer than 100 described cases of this neoplasm in the literature, and all previously published cases have been described in adults, with the majority occurring in the elderly. We present a case of an adolescent female with a syringocystadenocarcinoma papilliferum arising from a large thigh mass harboring an in-frame alteration in MAP2K1 along with a brief review of the literature.

Nevus Sebaceous of the Scalp With Stepwise Progression Into Invasive Syringocystadenocarcinoma Papilliferum

Syringocystadenocarcinoma papilliferum (SCACP), the malignant counterpart of syringocystadenoma papilliferum (SCAP), is an extremely rare malignant adnexal neoplasm. It is described by the World Health Organization as a malignant transformation of SCAP occurring in middle-aged to elderly individuals with a predilection for the head and neck. SCACP seems to arise from a long-standing syringocystadenoma probably on a background of nevus sebaceous (NS) through a multistep progression. A 75-year-old man was referred to our department with a long-standing NS with a recent newly developing nodule on his scalp. The tumor was excised. On histology, the overall architecture of the tumor still resembled an unusual SCAP within NS but simultaneously showed transition to syringocystadenocarcinoma papilliferum in situ and invasive SCACP as recognizable by the presence of areas of nuclear atypia, increased proliferative activity, and infiltrative growth. In summary, we report an extremely rare case of an invasive SCACP of the scalp that demonstrates histological evidence for all transitive steps in the hypothetical multistep progression from NS to invasive SCACP in one single lesion. The implications of these findings are discussed in the light of the relevant literature.

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

Extramammary Paget disease (EMPD) is a rare cutaneous malignancy that typically involves the genital skin and can be primary or associated with an underlying internal malignancy. The typical histopathological appearance of EMPD consists of single or small aggregates of cells with abundant pale cytoplasm and large pleomorphic nuclei, known as Paget cells, scattered throughout the epidermis. We report a case of anogenital EMPD occurring in a 53-year-old man with unusual histopathologic findings of marked epidermal acanthosis, acantholysis, intraepidermal glandular differentiation, and prominent plasma cell-rich fibrovascular cores. These features were entirely confined to the epidermis and adnexa with no evidence of dermal invasion or underlying systemic disease. We review and summarize the literature for atypical features noted in EMPD and summarize similar findings previously described under a variety of descriptions including anaplastic EMPD, anogenital syringocystadenocarcinoma papilliferum in situ (SCACPIS), SCACPIS-like changes in EMPD, and EMPD mimicking acantholytic squamous cell carcinoma in situ. We propose that these features represent a single entity and be considered under a unifying diagnosis to facilitate recognition of this entity.

Syringocystadenocarcinoma Papilliferum: A Case Report and Review of the Literature

Syringocystadenocarcinoma papilliferum (SCACP) is a rare malignant adnexal neoplasm, which is considered as a malignant counterpart of syringocystadenoma papilliferum (SCAP). Clinically, SCACP appears as a nodule, inflammatory plaque, or tumor. The lesion is usually covered with crusts, which are formed by secretion of the apocrine epithelial cells. Histologically, SCACP resembles SCAP, with cystic papillomatous invaginations connected to the skin surface by funnel-shaped structures lined by infundibular epithelium. The stroma of the tumor consists of a dense inflammatory infiltrate of plasma cells and lymphocytes. SCACP differs from SCAP in terms of the architectural and cytological features of the tumor cells, and is characterized by higher nuclear cytoplasmic ratio, nuclear irregularity, coarse chromatin, and increased mitotic activity. However, the immunohistochemical findings of SCACP vary. Since only 49 cases of SCACP have been reported in the English literature, the clinical and histologic characteristics of SCACP have not been fully established. Further studies on the diagnostic criteria for SCACP are warranted. Here, we report a rare case of SCACP and present a review of other relevant literature.

Syringocystadenocarcinoma papilliferum with orbital invasion: a case report with literature review

We present a case of Syringocystadenocarcinoma papilliferum that originated in the eyelid and extended into the orbit. These tumors are very rare and have the potential to metastasize. A literature review of all the previous cases has been compiled from the Medline, EMBASE, and PubMed databases. We found that the majority of cases present on the head and neck and up to 17% of cases showed metastatic progression. This is the first case to show orbital involvement and highlights the need to remain vigilant with such lesions, as they have a tendency to become aggressive.

Dermoscopy of syringocystadenoma papilliferum

Syringocystadenoma papilliferum is a benign adnexal neoplasm frequently seen in association with other adnexal tumours. We report the dermoscopic features of three cases of syringocystadenoma papilliferum developing in naevus sebaceus. Clinically the lesions were characterised by exophytic papillary structures. Dermoscopically, polymorphous vessels were the prevalent feature.