Main

Sir,

Primary ductal adenocarcinoma of the lacrimal gland is an uncommon tumour and there are only a few published reports.1,2 We report the third case of primary ductal adenocarcinoma of the lacrimal gland in a patient with neurofibromatosis and discuss the clinical presentation, radiological characteristics, treatment, and histopathological correlation of the tumour.

Case report

A 46-year-old Asian Indian male reported to our institution with complaints of slowly progressive proptosis of the left eye for the past 2 years. Skin examination disclosed numerous subcutaneous soft nodules suggestive of neurofibromas. He also had bilateral axillary freckles and numerous café au lait spots on the skin. A diagnosis of neurofibromatosis was made.

Examination of the right eye was normal and left eye revealed gross proptosis and a firm irregular mass in the orbit (Figure 1), more prominent in the superior orbit. The mass was nontender with no soft or cystic areas on palpation. The mass was not mobile. The bony orbital margins appeared intact. No pulsations or thrill was felt. The patient had been earlier diagnosed as a case of pseudotumour at another ophthalmic hospital for which he had been treated with 1 mg/kg oral prednisolone for 2 weeks and had also undergone a tarsorrhaphy with a view to prevent corneal exposure secondary to gross proptosis and lagophthalmos. Since no symptomatic improvement was noted, the patient decided to seek opinion at our centre. In view of severe globe protrusion and risk of exposure keratitis, it was decided to leave the tarsorrhaphy in place.

Figure 1
figure 1

Left eye showing proptosis with multiple neurofibromatosis on the face.

Full size image

Ultrasound examination of the left orbit revealed a large heterogeneous mass with variable reflectivity in the intraconal and extraconal spaces, especially in the medial and superior orbit. The optic nerve shadow could be seen separately from the lesion anteriorly.

Computerised tomography plain and contrast of the orbit and brain was perfomed. It showed an isodense homogeneously enhancing retrobulbar mass lesion with ill-defined margins in the left orbit. The mass displaced the globe inferolaterally and filled the retrobulbar space, both intraconal and extraconal. The mass was seen causing remodelling of the bony orbit; however, there was no evidence of bony destruction. No intracranial extension was noted. A clinical diagnosis of malignant orbital tumour of neural origin in a patient with neurofibromatosis was made.

After appropriate investigations, the patient was taken for early surgery. Intraoperatively, the tarsorrhaphy was divided and ocular examination revealed a normal globe with clear cornea, round pupil and attached retina. A combined superior and inferior orbitotomy was performed through a supratarsal fold incision superiorly and subciliary incision inferiorly. The firm homogeneous mass was debulked with careful dissection to separate it from levator aponeurosis and extraocular muscles. A vacuum drain was placed and the wound closed in layers.

Histopathological examination revealed a lacrimal gland tumour with large neoplastic ductal structures lined by malignant epithelial cells with large oval hyperchromatic nuclei and prominent nucleoli. The tumour showed both cribriform pattern and central comedonecrosis (Figure 2). Phosphotungstic acid haematoxylin stain (PTAH) was negative in the tumour cells.

Figure 2
figure 2

Photomicrograph showing lacrimal duct adenocarcinoma with well-circumscribed nodules of neoplastic ductal epithelium with comedonecrosis in the central area (haematoxylin and eosin × 200).

Full size image

A diagnosis of primary ductal adenocarcinoma of the lacrimal gland with orbital invasion was made. Systemic work-up for metastasis was negative. He underwent left orbital exenteration by lid-skin-sparing technique followed by postoperative radiotherapy to the socket. The patient is on a periodic evaluation by an oncologist for the past 19 months and has no recurrence.

Comments

Primary adenocarcinoma of the lacrimal gland is much less common than in salivary glands and represents 5–7% of epithelial malignancies in this location.3 Previous reports of lacrimal adenocarcinoma have classified these tumours together as a single entity of adenocarcinoma or adenocarcinoma not otherwise specified.4 However, recently ductal type of lacrimal adenocarcinomas have been reported 1,2 similar to histological subclassification of salivary gland carcinomas.5 Lacrimal ductal carcinomas have a highly aggressive nature similar to salivary ductal carcinomas.1

In the first case, the patient underwent modified en bloc orbitectomy with postoperative radiation therapy, and the patient was alive and well without evidence of tumour recurrence 10 months after surgery.1 In the second case, the tumour recurred in the subdural space after 2 years and it was removed.2 The three cases including our case had rapid growth of the tumour, and had sought medical evaluation within 2 years of onset. Neurofibromatosis represents a major risk factor for the development of malignancy, particularly orbital meningiomas, both primary and secondary, nerve sheath tumours and optic nerve gliomas.6

In conclusion, malignant orbital tumours have to be considered in the differential diagnosis of proptosis in patients with underlying neurofibromatosis. Lacrimal gland carcinomas have to be subtyped, to predict the biological behaviour of the tumour and the prognosis. The invasive nature of the primary ductal adenocarcinoma of the lacrimal gland dictates aggressive therapy. Combination therapy of wide surgical excision, or even orbitectomy followed by radiation therapy is sometimes required.