Case Report
A 46-year-old Japanese woman was referred to us with a 2-year history of multiple areas of erythema measuring 1-10 cm in diameter (Fig. 1a, b). The patient had been treated using topical steroids and narrow-band ultraviolet B irradiation for 2 years in another clinic. Peripheral blood tests showed a normal hemogram and a normal range of soluble interleukin-2 receptor; the patient was seronegative for anti-human T-cell leukemia virus type-1 antibody. Histopathological examination revealed that small-sized atypical lymphocyte-like hyperchromatic cells with haloes had infiltrated into the epidermis and upper dermis in a scattered manner (Fig. 1c). Tumor cells were primarily positive for CD4 but negative for CD30. The patient was diagnosed with patch-stage MF. Symptoms were well controlled by topical steroids and narrow-band ultraviolet B irradiation therapy.
Two years later, the patient noticed two rapidly growing tumors located on the MF patch-lesion in the left chest; the tumors had formed necrotic ulcers measuring 2-4 cm in diameter (Fig. 2a). Peripheral blood tests showed a normal hemogram and normal range of soluble interleukin-2 receptor. Imaging examinations revealed no invasion into the viscera. Histopathological examination showed nodular infiltration in the dermis and subcutis with necrotic changes of the epidermis (Fig. 2b). Anaplastic large cells (≥4 times the size of a small lymphocyte) had formed nodular nests in the dermis and subcutis (Fig. 2c). Small-sized atypical lymphocyte-like cells also had formed nodular nests, primarily in the subcutis (Fig. 2d). Most tumor cells were positive for CD3, CD4, and MIB-1 (Ki-67). Anti-CD30 antibodies were reactive to the anaplastic large cells (Fig. 2e, f), which comprised ≤75% of the tumor cells, but not to the small-sized atypical lymphocyte-like cells (Fig. 2g). The anaplastic large cells were reactive to antibodies against C-X-C motif chemokine receptor 3 (CXCR3) (Fig. 2h), but not to antibodies against C-C chemokine receptor type 3 (CCR3) (Fig. 2i). Based on these data, a diagnosis of MF-LCT in the patch-stage was made. Three months after their original appearance, the tumors spontaneously regressed, leaving scars (Fig. 2j). In the year since, no recurrence has been observed.