Thursday, June 11, 2009

MALT lymphoma

JP presents on MALT lymphoma.

68 yo with chronic nasal congestion. Sinus and chest CT revealed a R orbital mass (incidental finding). Biopsy obtained revealing an atypical lymphoid infiltrate, CD20+, monoclonal B-cell population. PET ct was positive in the R orbit alone. IEA MALT lymphoma of the orbit.

On exam conjuctival erythema noted with injected sclera, no other abnormalities.

Marginal Zone Lymphoma includes MALTs, Nodal marginal B-cell lymphoma (monocytoid lymphoma), Primary splenic marginal zone lymphoma.

3rd most common NHL (after DLBCL and FL). 7-8% of B-cell lymphomas. Most commonly occur in the stomach, and account for 50% of gastric lymphomas (the other half are DLBCLs).

Named due to subsite of origin within a lymph node/aggregate. Germinal center in the middle, mantle zone surrounding that, then the marginal zone surrounding that. Marginal zone residents are more mature lymphocytes.

Orbital subsite include the lacrimal gland, conjunctiva, retrobulbar region. Occaisionally the is bilateral presentations. (Technically this is a stage IV presentation, but biologically this would behave much more like a stage II).

Sjogren's syndrome associated with salivary gland MALT.

Infectious associations.
H. pylori has a large association with gastric MALT (92% of gastric MALTs show this).
C. psittaci associated with ocular adnexal MALT (80% of ocular adnexal MALTs from Italian work, though this is controversial in the US data).
C. jejuni and small intestine MALTs.
B. bordoferria and skin MALTs.

MALT B-cells are CD20+, CD21+, CD35+, IgM+

Gastric MALTs are initially treated with PPI, clarithromycin, amoxicillin, with a 50-80% response rate.

t11:18 (26-40% penetrance) trisomy 3, trisomy 18, all predict for antibiotic resistance. Occaisionally one also sees t14:18 (usually seen in follicular lyphoma).

Wundisch JCO 2005: 120 H pylori + with IAE gastric MALT, treated with H pylori eradication. 96/120 achieved CR with antiobiotic therapy, 24/120 went on to secondary treatment. With median f/u 6.3 years, continuous complete response in 77, histologic residual disease in 16 (all went into a CR with observation alone), 3 relapsed. contributions. 5 yr CCR rates were 71%. 5 yr OS was 90% in all patients, only 2 died of lymphoma (both transformed). 27% of CR patients showed an ongoing B-cell monoclonality.

Checter JCO 1998. MSKCC n=51 treated to 30Gy median dose, CR 96%, FFTF 4yr 89%, OS 4 yr, 83%, CSS 4 yr 100%.
Vrieling, Rad Onc 2008. Netherlands n=115 40 Gy median CR 96%, CaSS 10yr 94%.

Italian phase II. Ferreri JNCI 2006. 27 OAL (12 relapsed), 3 week course of doxycycline 100mg bid x 3 weeks. 41% positive for C. psittaci. FFS 3yr 66%. CR was 22%. Authors conclusion were that antiobiotics were promising, though certainly this is nowhere near the responses in gastric MALT to triple therapy.

Tsang IJROBP 2001. PMH. 70pts with MALT. Doses were 25-30Gy range. CR to RT was 96%. 5yr OS 96%. 5yr DFS 76% (only 69% in sites other than stomach and thyroid). LC with RT was 60/62 (crude). Failures tend to be in other regions were MALT occurs. Tsang JCO 2003 - (different patients?) with 5.1 yr median f/u, same results.

Bolek IJROBP 1999. UF. 38pt with 8.3 yr median f/u. All orbital lymphomas. Many had 20Gy or less, median dose 25Gy. In field local control 100%. In low grade tumors DFS at 5yrs was around 60%, worse for high grade tumors.

Pfeffer IJROBP 2004. 23 pts treated, 12 with partial orbital volumes, 11 with full orbit. No reccurences in the whole orbit. 4 recurrences (33%) in patients treated with partial orbital treatments. Therefore treat the region not the GTV alone with margin.

Treated with a wedge pair to the entire R orbit to 24Gy in 2Gy/fraction.

Potential Late Effects - Cataracts with this dose are extremely common. Dry eye may be common, but severity should be limited with <30Gy. Keratoconjunctivitis, corneal ulceration, retinitis, etc would be rare.

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