Apocrine hidrocystoma of the orbit mimicking basal cell carcinoma: a case report

¹Department B of Ophthalmology, Hedi Rais Institute of Ophthalmology, Tunis, Tunisia, ²Faculty of Medicine of Tunis, Tunis El Manar University, Tunis, Tunisia

^&Corresponding author
Racem Choura, Department B of Ophthalmology, Hedi Rais Institute of Ophthalmology, Tunis, Tunisia

Introduction    

Apocrine hidrocystomas are benign cystic lesions derived from the sweat glands. They are typically located on the face, particularly in the eyelid margins. Apocrine hidrocystomas are rarely seen in the orbit. Only very few cases in adults have been published in literature [1-4]. We present a case of a 40-year-old female, with no prior medical history or ocular trauma, referred for an orbital tumor.

Patient and observation     

Patient information: a 40-year-old female patient, presented in October 2019, with a bluish tumor of the inner canthus of the left eye. No history of ocular trauma was reported.

Clinical findings: on inspection, the lesion was bluish-gray, 10 mm in diameter, with a warty and pearly appearance, located in the internal canthus facing the lacrimal sac. It was firm and painless on palpation (Figure 1). The patient´s eye movements were unrestricted. There was no associated skin disorder, no neurological deficit or changes in visual acuity or optic nerve function.

Timeline of current episode: August 2009: the lesion appeared, and a scan has concluded to a cystic origin. A simple marsupialization of the cyst was performed. January 2016: First recurrence, a puncture was made. October 2019: Second recurrence. Due to the failure of previous treatments, the patient was referred to us.

Diagnostic assessment: the diagnosis of a basal cell carcinoma was suspected, and an excisional biopsy was indicated.

Therapeutic interventions: the excision of a skin spindle next to the tumor showed that the lesion is not cutaneous, but rather subcutaneous. We made a progressive dissection releasing the tumor from the surrounding tissue, then an enucleation and hemostasis (Figure 2). Finally, the skin has been sutured. The excised lesion was sent for histopathologic examination.

Follow-up and outcome of interventions: macroscopically, the mass was 10x7x0.5 mm in size, it contains a cyst, filled with fluid, of 8 mm long axis without any endo or exokystic vegetations. Histologically, the tumor presented a multilocular cyst with several juxtaposed cystic cavities. They are lined by a vascular and fibrous tissue wall composed by a double epithelial cellular layer. An outer layer composed of cubic flattened cells, and an internal thicker layer composed of secreting cylindrical cells, having an eosinophilic cytoplasm with a characteristic decapitation secretory apical prominence. The results of the pathologic analysis reported that the mass was consistent with apocrine hidrocystoma with no histological signs of malignancy (Figure 3).

Patient perspective: “I was scared. I thought I had cancer. Pathology results were a great relief for me.”

Informed consent: the patient gave written informed consent for surgical procedure and scientific participation.

Discussion     

The orbital location of apocrine hidrocystoma is extremely rare, as indicated by the few cases described in the literature, mainly after trauma [1-4]. Hidrocystomas are classified according to the type of secretion: eccrine or apocrine [1,5,6]. Both types can be found on the face, but the apocrine type is less likely to be in the periorbital area [1,7]. Hidrocystomas in the periorbital region are often located in the eyelid and inner canthus [6]. Aprocrine hidrocystomas tend to be darker, larger and solitary. Multiple forms are rare and may be an important marker for some rare inherited diseases [8,9]. Although benign, hidrocystomas may cause functional impact (closing of the palpebral slit and compression of the lacrimal duct), esthetic burden and psychological distress in patients [9]. The benign differential diagnosis of solitary apocrine hidrocystoma includes eccrine hidrocystoma, epidermoid or pilar cysts. The malignant tumor that may have a similar clinical presentation are mainly melanoma and basal cell carcinoma [8]. Our patient had a raised, pearly, firm, blue-grayish and slow-growing lesion that could be mistaken for a basal cell carcinoma. The pigmented appearance may be due to the presence in the cystic fluid of lipofuscin pigments [8]. The diagnostic confirmation is histological, but it may be suspected clinically. In our case, we performed a surgical excision, which is the only approach that allows the practitioner to carry out both the final diagnosis and the treatment of these tumors. A few years earlier, our patient had a needle puncture; however, local recurrence is frequently observed with this treatment. In the literature, no cases of spontaneously involuting apocrine hidrocystomas have been reported [8].

Conclusion     

Orbital apocrine hidrocystoma may mimic a basal cell carcinoma and, although rare, should be considered in the differential diagnosis of cystic mass of the orbit in any age group.

Competing interests     

The authors declare no competing interests.

Authors' contributions     

Slim Werda wrote the manuscript. Racem Choura revised the manuscript. Ahmed Chebil was involved in the clinical and therapeutic management of the patient. Leila El Matri is responsible for the overall scientific management. Racem Choura and El Ouafi Alexandre Bouazzaoui finalized the manuscript. All the authors read and approved the final version of manuscript to be submitted for publication.

Figures     

Figure 1: preoperative photography of the tumor: bluish-gray, with a warty and pearly appearance, located in the internal canthus of the left eye facing the lacrimal sac

Figure 2: preoperative photography: skin incision, dissection of the subcutaneous tissu, dissection of the tumor mass, and mass removal

Figure 3: histological confirming: multilocular cyst with several juxtaposed cystic cavities

References