Mycosis fungoides

Diagnosis of MF is made through an elliptical biopsy, particularly in the early stages it can be difficult to distinguish from other chronic skin conditions such as psoriasis or discoid eczema. The initial patch stage of the disease occurs when lymphocytes infiltrate the skin causing the patches or lumps to appear. As this is a disease which progresses very slowly, it may take years before the individual moves into the next phase of the disease (Figure 13.4). Table 13.4 is reproduced from the British Association of Dermatologist guidelines and indicates the survival rates for different stages of the disease (Whittaker et al., 2003). As the disease progresses the skin signs change too, moving from patches to thickened plaques and eventually on to skin tumours. Although the prognosis is generally good and treatment can control symptoms, abnormal cells can eventually infiltrate other organs including blood, lymph nodes, heart, liver, lungs and spleen (New Zealand Dermatological Society Incorporated, 2009). It may not be necessary to involve the multidisciplinary team in the care of someone who has very early MF, but throughout the later stages the input from specialist cancer services is vital.

Figure 13.4 Mycoses fungoides.

Table 13.4 Survival rates for cutaneous T-cell lymphoma.       IA   IB   IIA   IIB   III   IVA   IVB   OS at 5 years (%)   96–100   73–86   49–73   40–65   40–57   15–40   0–15   OS at 10 years (%)   84–100   58–67   45–49   20–39   20–40   5–20   0–5   DSS at 5 years (%)   100   96   68   80       40   0   DSS at 10 years (%)   97–98   83   68   42       20   0   Disease progression at 5 years (%)   4   21   65   32       70   100   Disease progression at 10 years (%)   10   39   65   60       70   100     Source: Whittaker et al. (2003). OS – overall survival DSS – disease specific survival

Treatments
Early stage MF (IA to IIA) can be treated conservatively with emollients and moderate potency topical steroids. However, dependant on the extent of skin signs and the thickness of the plaques, phototherapy (in the form of PUVA) and radiotherapy may need to be introduced. Resistant cases may need the addition of α-interferon to PUVA therapy. Patients with more advanced disease (IIB and above) will need to have systemic therapy which may include chemotherapy, immunotherapy or extracorporeal photophoresis (Whittaker et al., 2003). Novel retinoids are being developed for use in MF with the hope that there will be fewer toxicities associated with these forms of treatment.
As has already been mentioned, prognosis is good in the early stages of MF. However, as the disease progresses to later stages, treatment may become palliative and a key focus of care is to maintain comfort and as much quality of life as possible. If ulcerated lesions are present, these will require nursing intervention and consideration given to pain relief.