Folliculotropic mycosis fungoides successfully treated with narrow band UVB

ARTICLE

Auteur(s) : Tomonori Taniguchi, Yasuyuki Amoh, Kensei Katsuoka, Hiroshi Takasu

Department of Dermatology, Kitasato University School of Medicine, 1-15-1 Kitasato, Sagamihara, Kanagawa, 228-8555, Japan

A 56-year-old Japanese female was referred to our hospital with a 2-month history of indurated, erythematous plaques on her trunk and lower extremities. Initially, she had noticed a red plaque on the lateral aspect of her lower leg with other lesions gradually appearing over the period of 1 month (figure 1A).

A skin biopsy taken from a plaque with multiple papules on the right side of her abdomen showed a dense infiltrate of atypical lymphocytes with irregularly shaped nuclei around the hair follicle in the dermis, associated with distortion and destruction of follicular structures (figure 1B). The majority of those lymphocytes were positive for CD3, CD4, CD5 and CD25 but negative for CD8 and CD20. We diagnosed her condition as folliculotropic mycosis fungoides. Results of laboratory examinations, including full blood count, lactate dehydrogenase, and soluble IL-2 receptor were normal. Testing for HTLV-1 was negative. The immunogenotyping performed on the skin specimen showed rearrangement of the T-cell receptor Cβ1 gene chain constant regions. There were no abnormal findings in the whole body CT scan, ⁶⁷Ga citrate scintigram or PET. For treatment, the patient underwent narrow band UVB (NBUVB) phototherapy. Before treatment, we measured the minimal erythema dose (MED); the MED was 1.2 J/cm². The whole surface of the body was irradiated with 70% MED (0.8 J/cm²) on the first session, and the therapeutic dose was increased by 10% on the second session. The papules and nodules on her trunk and lower extremities decreased after eight exposures (total 3.68 J/cm²), after which she continued the irradiation at the same dose once a week. After 24 (total 12.3 J/cm²) exposures, all of the lesions had completely disappeared (figure 1C). On follow-up 3 years after her presentation, there were no new skin lesions.

Folliculotropic mycosis fungoides (FTMF), mycosis fungoides possessing affinity for follicular, is a rare clinical variant of cutaneous T-cell lymphoma, which is similar to conventional mycosis fungoides in its pathogenesis. The disease course is aggressive, and many patients show a poor outcome, particularly between 10 and 15 years after the initial onset of disease.

Psoralen plus UVA (PUVA) and NBUVB are common phototherapy modalities used for patch and plaque MF treatment. But FTMF is difficult to treat because the reservoir of follicular neoplastic cells is thought to be protected from the effects of superficial therapy. As such, PUVA therapy with oral bexarotene or with interferon alfa is regarded as effective therapy for this condition [1].

UVB has been shown to decrease the antigen-presenting capacity of Langerhans cells, increase interleukin-2 and interleukin-6 production by human keratinocytes, as well as increase the level of TNF-α. Therefore, UVB irradiation is thought to be therapeutic by suppressing the function of the neoplastic population of clonal T-cells in the skin and by serving as an up-regulator of the immune system [2]. However, apart from a report by Ryan and colleagues [3], we are unable to find other reports regarding the use of NBUVB for FTMF. FTMF is said to be more resistant to skin-directed therapies, such as topical steroid treatments [4] and NBUVB phototherapy, because the NBUVB rays do not reach the deep adnexal component, leaving deep residual disease [1]. But NBUVB phototherapy was effective in this case. We think that irradiation of thicker lesions may suppress the function of the neoplastic population of clonal T-cells surrounding the hair follicle. Other hand, irradiation may inhibit angiogenesis around stem cells in the hair bulge region [5, 6] and suppress the expansion of the tumor.

So it results in clinical clearing. We suggest that NBUVB phototherapy may be considered as a therapeutic option for patients with FTMF.

Acknowledgements

References

2 Guckian M, Jones CD. Immunomodulation at the initiation of phototherapy and Photochemotherapy. Photodermatol Photoimmunol Photomed 1995; 11: 163-9.

3 Ryan C, Whittaker S, D’Arcy C, O’Regan GM, Rogers S. Juvenile folliculotropic and ichthyosiform mycosis fungoides. Clin Exp Dermatol 2008; 34: e160-e162.

4 Ramsay DL, Lish KM, Yalowitz CB, Soter NA. Ultraviolet-B phototherapy for early-stage cutaneous T-cell lymphoma. Arch Dermatol 1992; 128: 931-3.

5 Amoh Y, Yang M, Li L, et al. Nestin-linked green fluorescent protein transgenic nude mouse for imaging human tumor angiogenesis. Cancer Res 2005; 65: 5352-7.

6 Amoh Y, Li L, Yang M, et al. Nascent blood vessels in the skin arise from nestin-expressing hair-follicle cells. Proc Natl Acad Sci USA 2004; 101: 13291-5.