Sebaceoma of the conjunctiva presenting as a chalazion.

Sir,

Chalazion is a chronic inflammatory granuloma of the meibomian gland. The major effects are cosmetic disfigurement with variable discomfort.[1] Microscopy reveals lipogranulomatous reaction caused by liberated globules of fat, surrounded by epithelioid histiocytes and multinucleated giant cells intermixed with neutrophils, lymphocytes, and plasma cells. Chalazion is usually treated by incision and curettage, although spontaneous resolution may take place in a few patients.[2]

In contrast, sebaceous epithelioma is a benign adnexal tumor with sebaceous differentiation.[3] It is also called sebaceoma to indicate its benign nature of the disease.[4] Sebaceous epitheliomas usually appear as yellow papules, nodules, or plaques, most commonly in areas with large numbers of sebaceous glands, such as the face. The eyelids have a large number of sebaceous glands that are modified and form zeis glands and meibomian glands. Sebaceous tumors, including sebaceous adenoma, sebaceous epithelioma, and sebaceous carcinoma, present as cutaneous markers of internal malignancy as in the Muir–Torre syndrome.[5] However, they can be solitary also, with no association with internal malignancy. Herewith, we report of a patient who clinically presented as a chalazion of the upper eyelid, but was found to be sebaceoma on histopathology.

A 50-year-old male presented with a painless swelling on the lateral one-third of his left upper eyelid since the past 3 months. On examination, his best corrected visual acuity in both the eyes was 6/12. The left eye revealed a swelling of 4 × 3 mm on the lateral one-third of the upper eyelid. The swelling was non-tender and firm in consistency with well-defined margins. There was mild induration of the skin with loss of eyelashes and overlying prominent vessels were noted [Figure 1a and b]. No regional lymphadenopathy was found. A provisional diagnosis of chalazion of the left upper eyelid was made and the patient underwent incision and curettage. On incising, a grain-like loculated material was seen, which on being subjected to a histopathological examination revealed sebaceoma.

Figure 1

(a) Swelling of the lid with madarosis and prominent vessels (b) Image of the everted lid showing swelling with mild vascularization along the lid margin

Histopathology revealed an adnexal neoplasm comprising basaloid cells admixed with sebaceous cells. Mitotic activity was inconspicuous and there was no evidence of stromal invasion. Proliferation activity of the tumor as measured by the Ki-67 (Mindbomb Homolog-1) index was <10% [Figure 2a and b]. The tumor was excised and lid reconstruction was performed for risk of malignant transformation of a sebaceoma. Following this, the patient was subjected to a thorough clinical examination, and had no features of the Muir–Torre syndrome or any other visceral neoplasms.

Figure 2

Basaloid cells exhibiting cytoplasmic vacuolation (H and E, ×40) (a) (Inset)-sections showing proliferative activity of <10% more concentrated on the periphery of the image (immunohistochemistry, DiAminoBenzidine stain, ×40) (b) tumor proper comprising predominantly basaloid cells with a focus on mature sebaceous differentiation (H and E, ×10)

Sebaceoma is a term proposed to designate a distinctive rare benign neoplasm of adnexal epithelium with differentiation toward sebaceous cells. Misago et al.,[6] in their study of 30 cases of sebaceous neoplasms, found fourteen sebaceomas, out of which two were eyelid sebaceomas accounting for 14.28% of the cases. Dinneen et al.,[7] in their study of 21 cases of sebaceoma, found only one in the eyelid accounting for 4.7% of the total sebaceomas.

McBride et al.[8] suggest that in normal sebaceous glands, p21WAF1-positive cells are only seen within the differentiating compartment, which is spatially distinct from the cycling peripheral Ki67-positive cells. In sebaceous adenoma and sebaceoma, topological control is maintained, with the distribution of markers being similar to that seen in normal sebaceous glands. The authors conclude that this distribution of markers is similar in sebaceous adenoma and sebaceoma although the proliferative compartment is expanded.

As sebaceomas are more common in syndromes such as the Muir–Torre syndrome, our patient was evaluated for evidence of systemic malignancies. In view of the risk of malignant transformation of sebaceoma and potential for local recurrence[9] local excision of the tumor with lid reconstruction was performed.