[ Home Page ] [ Site Map ]

Extranodal Peripheral T-cell Lymphomas

• Skin (cutaneous)
  • Mycosis Fungoides
  • Lymphomatoid Papulosis and CD30⁺ Cutaneous Lymphoma
• Small intestine

Cutaneous T-cell Lymphoma

Mycosis Fungoides

Clinical Presentation

• Presents as a diffuse erythematous rash that is often difficult to distinguish form eczema in its early stages.
• As the disease progresses the rash becomes more extensive and thickened to form an indurated.
• In late stage disease nodular tumours develop with involvement of lymph node and the peripheral blood.

Laboratory Diagnosis

• Morphological features in early disease may be difficult to distinguish from eczema. In these cases a further biopsy if these is no response to anti-eczema treatment
• Typical lesion show a peri-vascular or diffuse upper dermal infiltrate of small to intermediate sized T-cell. These cells show a greater degree of nuclear irregularity than is seen in normal reactive cells
• Invasion of the epidermis is a key feature. The intra-epidermal T-cells form aggregates with Langerhans cells (Pautrier abscess)
• In later stage disease tumour deposits may contain a high proportion of large lymphoid cells.
• Almost all cases of mycosis fungoides consist of CD4⁺ peripheral T-cells. However, CD7 and other pan-T-cell markers may be absent
• Most cases can be shown to have a clonal T-cell gene re-arrangement by PCR. This may occur in dermatitis reactions and is not exclusive to lymphoma.

Treatment and Outcome

• Mycosis fungoides is a progressive disease that is not cured by current therapy.
• Early stage disease may be treated using PUVA or topical steroids
• Electron beam therapy may be effective in controlling plaque phase disease.
• In late stage disease local radiotherapy and systemic chemotherapy may offer effective palliation.

Lymphomatoid Papulosis and CD30⁺ Cutaneous Lymphoma

Clinical Features

• Lymphomatoid papulosis is characterised by rapidly growing but self healing tumour nodules.
• CD30-positive cutaneous lymphoma has a similar presentation but does not spontaneously regress
• In neither case is there evidence of systemic disease.

Laboratory Diagnosis

• The lesion of Lymphomatoid Papulosis consists of central core that is rich in large highly pleomorphic CD30⁺ T-cells often associated with ulceration and necrosis. At the edges of the lesion there is a peri-vascular infiltrate of small lymphocytes.
• CD30⁺ Cutaneous Lymphoma may be difficult to distinguish from lymphomatoid papulosis on the basis of morphology alone.
• The CD30⁺ T-cells resemble the cells in anaplastic large cell lymphoma. They do not have evidence of the t(2;5) translocation. However, it essential to exclude systemic disease.

CD30 immunoperoxidase stain	Lymphomatoid papulosis skin section

Treatment and Outcome

• Lymphomatoid papulosis is a recurrent condition and is by definition self healing. In most cases no treatment is required
• CD30⁺ cutaneous lymphoma has an excellent prognosis when treated by excision and local radiotherapy.

Small Intestinal T-cell Lymphoma

Clinical Features

• Typically presents with a tumour mass in the distal small intestine often with perforation and peritonitis
• Some patients present with ulceration or bleeding
• In some cases there may be a history of symptomatic coeliac disease

Laboratory Diagnosis

Morphology

• In typical cases the diagnosis is made on a resection specimen, often removed as part of an emergency procedure for acute peritonitis
• There is full thickness replacement of the wall of the intestine by large highly pleomorphic lymphoid cells.
• The adjacent mucosa often shows villous atrophy. There are large number of intra-epithelial lymphocytes that may show cytological atypia
• Some patients present with intestinal ulceration. In these cases morphological identification of tumour cells may be difficult and there has been uncertainty as to how many of these patients have T-cell lymphoma. However, in at least a proportion of these cases immunogenetic and immunophenotypic studies are strongly suggestive of peripheral T-cell lymphoma
• A small group of patients have extensive intramucosal disease with a mass lesion.

Intestinal T-cell lymphoma	Intestinal T-cell lymphoma: CD7-immunoperoxidase staining.

Immunophenotype

• The tumour cells have an abnormal peripheral T-cell phenotype. In some cases there is absence of CD4 and CD8 expression. In others the tumour cells express CD56 and CD8 and contain cytotoxic granules.

Treatment and Prognosis

• Most patients are treated with surgery and combination chemotherapy although the outcome in most cases is very poor.

[ Home Page ] [ Site Map ]