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Editor,—Squamous cell carcinoma is a malignancy that occurs frequently on the skin of the eyelid; however, it is uncommon on the conjunctiva. The conjunctival form of the squamous cell carcinoma constitutes 7–15% of conjunctival and corneal epithelial tumours.12 This malignancy normally behaves in a non-aggressive fashion, and the most rare form of this tumour is the palpebral conjunctival squamous cell carcinoma.3 We report a case of primary conjunctival squamous cell carcinoma of the palpebra treated successfully with surgical excision and cryotherapy.
A 69-year-old woman with a 2 year history of ocular discomfort and lacrimation was referred to us with a clinical diagnosis of papilloma. The tumour was surgically excised in another institution with recurrence of the tumour in the same eyelid location.
Eversion of the left upper eyelid disclosed a papillary tumoral mass over the tarsus in the palpebral conjunctival surface, extending 2.5 mm from the posterior eyelid margin to the superior fornix, measuring 10 × 12 mm (Fig 1). Incisional biopsy revealed squamous cell carcinoma. No regional adenopathy was present.
Treatment consisted of surgical excision of the tumour with a 2 mm safety margin, and cryotherapy was applied to the underlying tissue using the cryoprobe technique. Histopathological examination disclosed a moderately differentiated squamous cell carcinoma arising from the palpebral conjunctiva (Fig 2). Malignant cells formed nests or sheets of epithelial cells. They had scant eosinophilic cytoplasm and intercellular bridge. Mitosis was sparsely observed in the specimens. The basement membrane of the conjunctiva was infiltrated in several areas by the tumoral cells.
Three months after surgical excision of the tumour, a multiple conjunctival and tarsal biopsy was performed on the upper eyelid. The findings were negative for tumour. In the tarsus abnormal epithelial cell growth was observed but no malignant changes were found. In a 12 month follow up there was no recurrence of the tumour.
In situ hybridisation for human papilloma virus types 6, 11, 16, 18, 31, 33, and 51 was negative.
Conjunctival squamous cell carcinoma of the palpebra is very rare. In our review of the literature, it appears that only seven cases have been reported previously.3-6
Recently, human papilloma virus (HPV) antigens and DNA have been detected in conjunctival neoplasia, and their implication in the pathogenesis of squamous cell carcinoma and other epithelial tumours has been suggested.7 We applied in situ hybridisation to detect HPV types 6, 11, 16, 18, 31, 33, and 51 in paraffin embedded tissue. HPV was not present in the specimens. This finding suggests that, in this patient, HPV was not associated with squamous cell carcinoma of the conjunctiva.
Conjunctival squamous cell carcinoma can be treated successfully with excision, radiotherapy, or cryotherapy. In the series of three patients described by Theodore, conjunctival squamous cell carcinoma was treated with intense radiotherapy.4
Thygeson reported on two patients with papillary squamous cell carcinoma of the palpebral conjunctiva. One of these patients received radiation therapy and the other was treated with excision of the tumour.5 Goldberg et al reported on a patient with invasive squamous cell carcinoma of the palpebral conjunctiva, masquerading as chronic conjunctivitis, who was treated with radiotherapy for a total dose of 54 Gy.6 The tumour recurred after 7 weeks of follow up. This patient died from complications of metastatic breast carcinoma.
Our patient had a tumour histopathologically classified as moderately differentiated squamous cell carcinoma. Surgical and cryotherapy were successfully used without recurrence of the tumour or metastasis after a 1 year follow up.
Several reports of squamous cell carcinoma of the conjunctiva masquerading as chronic conjunctivitis have been reported.4-6 Our patient had a history of lacrimation and ocular discomfort which are symptoms of conjunctivitis. This factor probably delayed the correct diagnosis. Squamous cell carcinoma of the conjunctiva must be considered as a differential diagnosis in patients with unilateral chronic conjunctivitis.