Syringocystadenocarcinoma papilliferum with transition to areas of squamous differentiation: a case report and review of the literature

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.

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.

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.

Syringocystadenocarcinoma papilliferum: Clinicopathologic analysis of 10 cases

BACKGROUND

Syringocystadenocarcinoma papilliferum (SCACP) is an exceedingly rare cutaneous adnexal neoplasm. We aimed to investigate the clinicopathologic and immunophenotypic features of SCACP, and to discuss the prognosis of this rare entity.

METHOD

We retrospectively collected clinical, pathological and follow-up data of 10 cases with SCACP.

RESULTS

There were 8 males and 2 females, with ages ranging from 26 to 74 years. The chest was most frequently involved. Histologically, 1 case only showed SCACP in situ, 9 cases presented with variable invasive components of adenocarcinoma and/or squamous cell carcinoma in addition to areas of in situ. Apocrine differentiation with decapitation was evident in 4 cases and mucinous metaplasia was noted in 1 case. P63 was positive in invasive squamous cell carcinoma, while CK7 was variably positive in invasive adenocarcinoma. Regional lymph node metastasis was confirmed by pathological examination in 4 patients. Follow up was available for 9 patients, ranging from 3 to 112 months. Three patients died of the disease within 1 year after recurrences.

CONCLUSIONS

Because of high rates of regional lymph node metastasis and mortality in our patients, clinical behavior of SCACP seems to be more aggressive than that previously reported.

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

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.

A Histological Snapshot of Hypothetical Multistep Progression From Nevus Sebaceus to Invasive Syringocystadenocarcinoma Papilliferum

Syringocystadenocarcinoma papilliferum (SCACP) is an extremely rare adnexal neoplasm, believed to arise in a preexisting nevus sebaceus of Jadassohn (NSJ) through a multistep progression process. This hypothetical process involves an NSJ giving rise to syringocystadenoma papilliferum, which then presumably undergoes malignant transformation in rare circumstances to give rise to SCACP in situ, which finally progresses to an invasive SCACP. Of the 30 SCACP cases reported so far, none have documented the process from a birthmark to the final invasive lesion, with histological evidence of each step, in a single tumor. Here, the authors report just such a case. A 74-year-old man presented with a recently enlarging birthmark on the scalp. Excisional biopsy showed an invasive SCACP, in the background of SCACP in situ, syringocystadenoma papilliferum, and NSJ. Furthermore, this tumor showed a concurrent pigmented trichoblastoma and histological evidence of lymphovascular invasion, events that have not been documented with SCACP. Interestingly, all these component lesions were present on a single histological section of this solitary tumor. Regional lymph node metastasis, a rare occurrence in SCACP, was also present in this remarkable case. The authors discuss the implications of these findings in light of the review of relevant literature.

Syringocystadenocarcinoma Papilliferum in the Perianal Area

Syringocystadenocarcinoma papilliferum (SCACP) is a very rare cutaneous adnexal neoplasm. SCACP presents histologic variability, and it is difficult to establish the diagnosis from a punch biopsy. SCACP has an overall configuration similar to that of syringocystadenoma papilliferum (SCAP). When we diagnose SCACP, the histologic features of SCAP can be contributing and immunohistochemical staining is useful. Our case shows the histologic variability of SCACP and the pitfalls of a punch biopsy for the diagnosis of SCACP.

Syringocystadenocarcinoma papilliferum in situ: report of a case with late recurrence

Syringocystadenocarcinoma papilliferum (SCACP) is an extremely rare cutaneous neoplasm with apocrine differentiation. Only 27 cases have been reported up-to-date, 8 of them described as carcinomas in situ. Two cases with local recurrence and 3 cases with regional lymph node metastases have been documented. The authors present the case of a 32-year-old female with a SCACP in situ on the scalp that recurred 8 years after the excision of the primary tumor. No SCACP with late recurrence have been previously reported. This case highlights the need for a long-term follow-up in patients with this type of carcinoma.

A new case of syringocystadenocarcinoma papilliferum: a rare pathology for a wide-ranging comprehension

We report a new case of p63/cytokeratin 7 (CK7) positive syringocystadenocarcinoma papilliferum (SCACP), on the shoulder of an 88-year-old man, with superficial dermal infiltration and squamoid differentiation. We describe the 24th case of SCACP, the malignant counterpart of syringocystadenoma papilliferum (SCAP). At the present, we do not know whether SCACP arises from eccrine or apocrine glands because of the contrasting opinions in the literature. Only few histochemical and ultrastructural studies have previously advised that SCACP could arise from pluripotent stem cells. Through our case, we wish to suggest the stem cell-like properties of the syringocystadenocarcinoma papilliferum. This rare neoplasm shows two different patterns of stem cell marker expression in the glandular and squamous components, respectively. For the double phenotype of SCACP, we propose it like an intriguing model to study histogenesis and stem cell properties for more wide-ranging epithelial tumors.