Abstract
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.
Introduction
Syringocystadenocarcinoma papilliferum (SCACP) is a rare malignant sudoriferous gland tumor that is related to its more common, benign counterpart, syringocystadenoma papilliferum (SCAP). Since the original description of SCAP in 1917, 1 only 43 cases of SCACP have been described in the literature. To date, only one has appeared in the eyelid. 2 SCACP is thought to develop from SCAP, nevus sebaceous, and linear nevus verrucosus lesions. 3 However, due to the rarity of this tumor, little is known regarding its etiology and origin. 3
In this study, we report the first case of SCACP with orbital involvement. Interestingly, it recurred following exenteration. An informed written consent was obtained from the patient for the publication of medical data and images.
Case report
A 63-year-old man presented with a lesion on the right upper eyelid that had been present for 7 years. The lesion was nodular, measuring 5.0 cm × 7.0 cm, ulcerated, indurated, and erythematous. It involved the lower eyelid (Figure 1). The patient had no light perception with the right eye and had a visual acuity of 20/20 on the left. Due to the presence of the tumor over the right eye, his intraocular pressure could not be measured, and it was found to be 18 mmHg on the left.

Lesion on presentation.
The left orbital examination did not reveal any abnormalities. A full examination of his local lymph nodes and lacrimal duct did not reveal any abnormalities. He explained that he did not have any previous therapy for this lesion. He was otherwise systemically well with no relevant family history. He did not have any history of trauma and informed us that he was a farmer by occupation.
A computed tomography (CT) scan of the orbit revealed right anterior orbital invasion with no bony or lacrimal gland involvement (Figure 2). A subsequent incisional biopsy revealed squamous cell invaginations extending from the epidermis into the dermis. The invaginations and papillary projections were lined with a bilayer epithelium: the luminal layer was composed of columnar cells with decapitation secretion and the outer layer was composed of small cuboidal cells. These cells had significant nuclear pleomorphism, prominent nucleoli, and increased mitotic activity (Figure 3). Immunohistochemical staining demonstrated positivity for epithelial membrane antigen (EMA), Cytokeratin 8/18, and a Cytokeratin cocktail of high and low density (Figure 3). It was negative for GCDFP-15 (protein 15 of the fibrocystic disease of the breast), which excluded a lesion of breast origin and carcinoembryonic antigen (CEA). The diagnosis of SCACP was therefore confirmed. A positron emission tomography (PET) scan did not reveal any metastatic spread.

CT imaging of the lesion at presentation.

Hematoxylin and eosin staining (H&E): (a) the transition between squamous and glandular epithelium (100×). (b) Large areas of superficial epithelium were sphacelated. Glandular invaginations showed a characteristic funnel shape. Papillary structures can be identified inside a dermal cyst (100×). (c) The papillary structures are lined with a stratified atypical epithelium. Micropapillae and secretion by decapitation can be seen (100×). (d) At high power magnification, atypical nuclei are evident. Large atypical nuclear shapes are seen and increased mitotic activity is observed (*).
The patient was treated with exenteration of the right orbit to remove the tumor. After 11 months of follow-up, we noted local recurrence of the original tumor (confirmed with biopsy) in the anophthalmic orbit. There was no associated lymph node enlargement on examination, though the patient refused any further imaging. Radical exenteration with adjuvant radiotherapy has been planned for the patient.
Discussion
SCACP is an extremely rare adnexal neoplasm of the sweat glands and has only been documented 43 times in the literature. It is believed to arise from a malignant transformation of SCAP lesions. 4 Clinically, it may present as an asymptomatic long-standing lesion, which may be flat or nodular, cystic, or ulcerated. We performed a literature review of the Medline, EMBASE, and Cochrane databases to characterize the cases previously listed in the literature (Table 1).
Previous case reports on SCACP.
Ct, chemotherapy; Rt, radiation therapy; N/A, not available; NED, no evidence of disease; DOD, died of disease.
The tumor appears to affect middle-aged or elderly individuals 15 and does not seem to have a gender bias. The most frequent location is the head and neck (53%), with only one case in the eyelid. Other locations where these lesions occur frequently are the back, chest, suprapubic, and perianal regions.
Treatment is based on a complete tumor resection with oncological margins, which is essential for a better prognosis. Mohs surgery has also been successfully used for this purpose. 11 Sentinel lymph node biopsy may be feasible in some cases when there is suspicion of lymph spread, although lymphatic spread has been shown to be rare with this tumor (6 of the 42 documented cases; Table 1). Radiotherapy and chemotherapy have also been used rarely, but the experience with these treatments is scarce due to the rarity of the lesion. 25
SCACP characteristically presents with squamous cell invaginations extending from the epidermis into the dermis. The invaginations and papillary projections are lined by two-layer epithelium: the luminal layer composed of columnar cells with decapitation secretions and the outer layer composed of small cuboidal cells. The immunohistochemical features of SCACP are still under study, but the most frequently reported markers are CEA,15,20,28 followed by EMA,9,28 GDFP-15,20,28,32 and cytokeratin.11,28,32
Due to its appearance, the differential diagnosis includes other skin tumors such as basal cell carcinoma, squamous cell carcinoma, sebaceous carcinoma, metastatic breast or gastrointestinal adenocarcinomas, and other sweat gland neoplasms.2,20
Of the cases that reported head and neck involvement, 16 (72.72%) were in remission following therapy, 2 (9.09%) had local recurrence, 3 (13.63%) had regional lymphatic invasion, and 1 (4.54%) had distant metastases. Of the reports describing involvement of the thorax, abdomen, and pelvis, 17 (85%) went into remission following therapy, none had local recurrence, 1 (5%) had regional lymphatic invasion and 2 (10%) had distant metastases.
This is the first reported case of SCACP with extension into the anterior orbit. While SCACP is an exceedingly rare tumor, we found that of the reported cases, 16% showed signs of metastasis. It is therefore an important diagnosis to consider when reviewing skin lesions around the orbit. It also encourages us to monitor patients with SCAP more closely as our literature review suggests that SCACP may be more aggressive than previously considered.
