Cystic sebaceous carcinoma: is it a constant pathognomic marker for Muir-Torre syndrome?

Journal of Drugs in Dermatology, May, 2007 by Hani A. Al-Shobaili, Khalid M. AlGhamdi, Walid A. Al-Ghamdi

Abstract

Sebaceous carcinoma (SC) is a rare and aggressive cutaneous neoplasm. It may arise in ocular or extraocular sites. Approximately 25% of all reported cases of SC are extraocular. Cystic presentation of sebaceous neoplasm is rare. So far, cystic sebaceous neoplasia (CSN) has been reported only in association with Muir-Torre syndrome (MTS). Furthermore, CSN has recently been characterized as a marker lesion of MTS. We report a case of CSN of the nose that was not associated with MTS. Mohs micrographic surgery was performed with no recurrence for 2 years. Patients with MTS need long-term follow-up to detect possible future presentation of MTS.

Introduction

Sebaceous carcinoma (SC) is a rare tumor arising from holocrine adnexal components of the skin. (1) It may arise in ocular or extraocular sites. (2) Approximately 25% of all reported cases of SC are extraocular. (3) Cystic presentation of sebaceous neoplasm is rare. Recently, cystic sebaceous neoplasia (CSN) has been characterized as a marker lesion of Muir-Torre syndrome (MTS). (4,5) So far, CSN has been seen only in patients with MTS. (4,5) One study confirmed the presence of SC in 30% of patients with MTS. (6)

Case Report

A 55-year-old woman presented with a 3-year history of a progressively enlarging asymptomatic skin lesion on her nose. The lesion was partially excised one year earlier in a different hospital. Unfortunately, there was no histopathologic confirmation and the lesion started to regrow. There was no history of other lesions on the body, radiation exposure, systemic symptoms, or other family members being affected with the same problem.

Cutaneous examination revealed a well defined round 1.5 x 1.5 cm firm skin-colored nodule over the dorsum of the nose (Figure 1). A histopathologic examination was suggestive of a ruptured follicular cyst.

Six months later, she presented with a progressively enlarging fluid containing cyst over the dorsum of the nose with a watery discharge (Figure 2). An excisional biopsy showed a lobulated infiltrate of malignant cells with foamy cytoplasm and atypia separated by fibrovascular stroma. These histopathologic findings were compatible with SC (Figures 3a-b). A retrospective study of the initial biopsy was also consistent with SC.

Mohs micrographic surgery was done with 3 levels for the base to achieve free margins status. The size of the final defect was 3 x 2 cm. A complete blood count with differential liver function tests, urea, and electrolytes was normal. Urine cytology, colonoscopy, and a computed tomography of the abdomen, chest, and pelvis were normal.

[FIGURE 1 OMITTED]

No recurrence of the lesion was seen during the 2-year close follow-up period.

Discussion

SC is a rare (7) and aggressive cutaneous neoplasm. (8) The general frequency of this tumor varies from 0.2% to 4.6% of all malignant cutaneous neoplasia. (9,10) There is a greater frequency for SC in the Asian population in comparison to other skin cancers. (11) SC may arise in ocular or extraocular sites. (2) SC occurs more commonly on the head (75%) with selective affinity for the eyelids or, less frequently, on the scalp, or other areas of the face. (12) It can, however, arise anywhere including the skin of the trunk (15%) or the limbs (10%). (13,14)

Approximately 25% of all reported cases of SC are extraocular. (3) In extraocular SC the sex distribution is equal, while females tend to be affected more by ocular SC. (7,11) There are few isolated case reports of nasal sebaceous cancers. Bailet et al found only 400 cases of SC worldwide, whereby 91 of these were extraocular and only 19 (5%) were in the region of the nose, without specification of the actual site. (7)

The etiology of SC is unknown. However, SC has been reported in patients with a history of ionization exposure (15) and it is possibly linked to human papillomavirus (HPV) infection. (11) Few SCs are associated with MTS. (16) MTS is an autosomal dominant condition with variable penetrance. (11) Clinically, a diagnosis of MTS is made by the presence of at least one sebaceous gland tumor (adenoma, epithelioma, carcinoma, cystic sebaceous tumor, or keratoacanthoma with sebaceous differentiation) associated with at least one primary visceral malignancy. (17) Alternatively, diagnosis of MTS can be made if the patient has multiple keratoacanthomas with multiple internal malignancies and a family history of MTS. (17) The skin lesions are most commonly sebaceous adenomas, but sebaceous epitheliomas and carcinomas also occur in MTS. (18) Of the 205 cases of MTS reported by Akhtar et al, sebaceous tumors appeared before the internal malignancy in 22%, concurrently in 6%, and after the internal malignancy in 56%. (19) The total number of sebaceous gland carcinomas in MTS reported is 44; and 17 out of 44 were neoplasms of the meibomian glands. (19) Evaluation for this syndrome should include a rectal examination, a colonoscopy, and a urine cytology. (11) In this case, all investigations were normal; thus MTS was excluded up to this stage.