Patients with mucosa-associated lymphoid tissue (MALT) lymphoma of the ocular adnexae (MLOA) will be eligible for treatment with doxycycline (part A: clinico-pathological study); patients with other types of ocular lymphoma, inflammatory lesions or those ineligible/unwilling for treatment with doxycycline can participate in the only pathologic study (part B).

Patients with suspected lymphoma of the ocular adnexae will undergo a diagnostic biopsy in the usual way. If lymphoma is confirmed the patient will undergo a full staging evaluation and entry into either part A or B of the study will then be considered as follows:

• clinico-pathological (part A) for patients with MALT lymphoma of the ocular adnexae (MLOA) and eligible for treatment with Doxycycline 100 mg twice daily for 3 weeks ; or
• pathology only (part B) for patients with other types of ocular lymphoma, inflammatory lesions or those ineligible/unwilling for treatment with doxycycline.

Inclusion Criteria:

1. Age 18 years or over
2. Histologically confirmed marginal zone B-cell lymphoma of MALT-type
3. Lymphoma localised to the ocular adnexae (conjunctiva, lacrimal gland, orbit soft tissue, clinical stage IEA) following a CT scan of neck, thorax, abdomen and pelvis, bone marrow aspirate/trephine, full blood count and biochemical profile
4. No previous treatment, excepting RT for localised lymphoma of the contralateral eye
5. At least one measurable lesion
6. No systemic antibiotic therapy in the last three months
7. No other malignancy in the previous 5 years apart from appropriately treated basal cell carcinoma of the skin or carcinoma in situ of the cervix
8. In women with reproductive potential a willingness to use contraception from entry into the study for a period of 3 months
9. Written informed consent

Exclusion Criteria:

1. Pregnant or lactating women
2. Known allergy to tetracycline
3. Patients unwilling to comply with the requirements of follow-up as defined by this protocol
4. Myasthenia gravis (tetracycline can exacerbate muscle weakness)
5. Systemic lupus erythematous (tetracycline can exacerbate the condition)
6. Patients with large or rapidly enlarging tumours requiring immediate radiotherapy