PERIPHERAL T-CELL LYMPHOMA
Patients with peripheral T-cell lymphoma have diffuse large cell or diffuse
mixed lymphoma that expresses a cell surface phenotype of a postthymic (or
peripheral) T-cell expressing CD4 or CD8, but not both together.
Peripheral T-cell lymphoma encompasses a group of heterogeneous nodal T-cell
lymphomas that will require future delineation. This includes the so-called
Lennert’s lymphoma, a T-cell lymphoma admixed with a preponderance of
lymphoepithelioid cells. Most investigators report worse response and survival
rates for patients with peripheral T-cell lymphomas than for patients with comparably staged B-cell aggressive
lymphomas.[140,141,142] Therapy involves doxorubicin-based combination
chemotherapy, which is also used for B-cell diffuse large cell lymphoma. Most patients present
with multiple adverse prognostic factors (i.e., older age, stage IV, multiple
extranodal sites, and elevated LDH), and these patients have a low (<20%)
failure-free survival and OS at 5 years. High-dose chemotherapy with
hematopoietic stem cell support has been applied to patients with advanced-stage peripheral T-cell lymphoma. Evidence for this approach is
anecdotal.[137,143] Anecdotal responses have also been seen with alemtuzumab, an anti-CD52 monoclonal antibody, or denileukin difitox, a toxin-antibody ligand, after relapse from previous chemotherapy.[144,145] An unusual type of peripheral T-cell lymphoma occurring mostly in
young men, hepatosplenic T-cell lymphoma, appears to be localized to the
hepatic and splenic sinusoids, with cell surface expression of the T-cell
receptor gamma/delta.[146,147,148,149,150] Another variant, subcutaneous panniculitis-like
T-cell lymphoma, is localized to subcutaneous tissue associated with
hemophagocytic syndrome.[151,152,153,154] These patients have cells that express alpha/beta phenotype. Those with gamma-delta phenotype have a more aggressive clinical course and are classified as cutaneous gamma-delta T-cell lymphoma.[155,156,157] These patients may manifest involvement of the epidermis, dermis, subcutaneous region, or mucosa. These entities have extremely poor prognoses
with an extremely aggressive clinical course and are treated with the same
paradigm as for the highest-risk groups with diffuse large B-cell lymphoma.
ENTEROPATHY-TYPE INTESTINAL T-CELL LYMPHOMA
Enteropathy-type intestinal T-cell lymphoma involves the small bowel of
patients with gluten-sensitive enteropathy (celiac sprue).[126,158,159] Since a
gluten-free diet prevents the development of lymphoma, patients diagnosed with
celiac sprue in childhood rarely develop lymphoma. The diagnosis of celiac
disease is usually made by finding villous atrophy in the resected intestine.
Surgery is often required for diagnosis and to avoid perforation during
therapy. Therapy is with doxorubicin-based combination chemotherapy, but
relapse rates appear higher than for comparably staged diffuse large cell
lymphoma.[159,160] Complications of treatment include gastrointestinal bleeding, small
bowel perforation, and enterocolic fistulae; patients often require parenteral
nutrition. Multifocal intestinal perforations and visceral abdominal
involvement are seen at the time of relapse. High-dose therapy with hematopoietic
stem cell rescue has been applied in first remission or at relapse.
Evidence for this approach is anecdotal.