Multiple heterotopic sebaceous glands in the oesophagus: A case report and literature review

Introduction

Sebaceous glands originate from ectoderm and are associated with hair follicles. They are found in the facial skin, buccal mucosa, lips, prepuce, labia minora and parotid glands. Ectopic sebaceous glands are found in various tissues of ectodermal origin, such as the palms, soles, nipples, external genitalia and parotid glands. ¹ Thus, sebaceous glands are rarely found in the oesophagus, ² whose origin is endoderm. Ectopic sebaceous glands were first reported as small yellow nodules on the mouth and lips in 1896 and were named Fordyce spots^{. 3} They have been reported in the genitals, eyes and orbits, nipples, palms, soles of feet and parotid glands, ⁴ but ectopic oesophageal sebaceous glands are very rare. The basis of original findings is based on 200 autopsies performed in 1962, where c. 2% of such cases were found.

Case report

Our patient was a 46-year old female who presented with upper abdominal discomfort for one week. There had no history of hereditary familial disease or malignancy. She confessed to a long history of betel nut chewing. Oesophagoscopy showed that from 20–40 cm to the incisor, the middle to lower segment of the oesophagus, there were hundreds of light-yellow plaques, varying in size from 1 to 5 mm, distributed in clusters, and embedded in the inner lining of the oesophagus. Their apices were accompanied by fine grey-white particles with clear boundaries. The larger lesions were lobed or petal-shaped.

There were no endoscopic manifestations of reflux oesophagitis. An initial endoscopic diagnosis was xanthoma of the oesophagus. Excision of a 0.1 cm sized single piece of oesophageal tissue at 28 cm from the incisors was performed and sent for histological examination (Fig. 1). This revealed tissue covered with non-keratinised squamous epithelium, with a slight increase in size of the squamous epithelium layer. The nuclear size and shape were relatively consistent, and there were no obvious heterotypic and pathological mitotic figures. Transparent or slightly eosinophilic cell clusters were visible in the stratified, flat squamous epithelium and submucosa. The cell clusters were distributed in the small lobules, each of which was composed of polygonal cells with small nuclei and an abundant transparent foam-like cytoplasm, reminiscent of mature sebaceous gland cells. No hair follicle structures were observed (Fig. 2).

Figure 1.

Endoscopic appearances of ectopic oesophageal sebaceous glands: 20–40 cm from the incisor, the middle segment of the oesophagus to the lower segment of the oesophagus, there were numerous light-yellow plaques, varying in size from 0.1 to 0.5 cm, distributed in clusters, embedded in the inner lining of the oesophagus. The top was accompanied by grey white fine particles, well delimited. The larger lesions were lobed or petal-shaped ( the larger lesions).

Figure 2.

Haematoxylin–eosin staining of ectopic oesophageal sebaceous glands. The non-keratinised squamous epithelium exhibited slight hyperplasia. Clear or slightly eosinophilic cell masses with nest-like/glandular distribution can be seen in the stratified flat squamous epithelium and the lamina propria of the mucosa. The cell clusters had small nuclei and transparent foam-like cytoplasm.

The circular microvessels that can be seen on magnified endoscopy may be caused by the displacement of blood vessels owing to the presence of the subcutaneous ectopic sebaceous glands in the lamina propria mucosa. ⁶

No histological features of reflux or infectious oesophagitis were observed. After a follow-up of six months, the patient showed no significant abnormalities.

Literature review

We reviewed 11 earlier reports of ectopic oesophageal sebaceous glands^7–17 and summarised their clinical and endoscopic findings in 19 patients. Patients had an average age of 55.9 years, with a span of 33 to 71 years. There were 12 males. Most ectopic glands were located in the middle and lower parts of the oesophagus. The number of lesions varied from single to >100, with a size between 0.5 and 5 mm. One case had scattered lesions throughout the oesophagus.

Endoscopically, the lesions seen were whitish punctate or light yellow plaques, whitish yellow spots, yellow flat nodules, greyish yellow nodules, granular lesions, or light yellow, patchy, locally fused white needle-like protrusions on the surface.

Clinical symptoms included heartburn, dyspepsia, dysphagia, reflux, foreign body sensation, gastric distension, upper abdominal distension, upper abdominal pain and retrosternal choking sensation. Two patients had a history of previous gastroesophageal reflux.

None of the 19 patients underwent follow-up examination.

Discussion

A study of 215,046 patients in Taiwan ² showed incidence and prevalence rates of oesophageal sebaceous glands in 0.00465% and 0.41 per year, respectively. The male to female ratio was 3:1, and the average age was 57.6 years (range 46–71 years). Endoscopic examination revealed pale yellow papules or nodules with an irregular surface, occasionally with small central tubular openings. The size and number of lesions varied from 1 to 20 mm. The number of lesions ranged from one to more than 100. The most common sites were the middle and lower oesophagus.

Although no specific clinical symptoms have been reported, as the pick-up of this condition requires endoscopy, most patients would have had some indication for having this done.^18,19

Two hypotheses have been proposed: first, sebaceous glands may be congenital abnormalities developing heterotopically in the oesophagus; second, these glands may represent metaplastic changes in patients with gastroesophageal reflux disease. ¹⁹ As ectopic sebaceous glands in the oesophagus have never been reported in children but are more common in the elderly, the second theory has greater traction; furthermore, smoking, betel nut chewing and alcohol consumption appear to increase the frequency, all producing oesophageal irritation. ⁶

Other endoscopically observed oesophageal yellow lesions include candidiasis, carcinoids, granulosa cell tumours, xanthomas and leiomyomas. Both xanthoma and candida are most likely to be confused with ectopic sebaceous glands.^19–22 In most cases, endoscopic biopsy can provide a definite diagnosis; but biopsies obtained using endoscopic forceps are sometimes insufficient, as the ectopic sebaceous glands are located in the depth of the lamina propria, which requires endoscopic occlusal biopsy. ⁵ Therefore, a superficial endoscopic biopsy may miss the diagnosis and be a reason for the low detection rate of ectopic sebaceous glands in the oesophagus.

Most scholars however believe that ectopic sebaceous glands are completely benign and require no special treatment.^10,23