Non-folliculotropic Milia in a Treated Case of Mycosis Fungoides: A Rare Occurrence.

Sir,

A 68-year-old woman presented with persistent pruritic, erythematous eruptions on the trunk and extremities of 6 years’ duration. The eruptions gradually extended, and several nodules developed 1 month previously. Physical examination showed infiltrative erythematous, pigmented patches and plaques, as well as ulcerative nodules on the trunk, palms, and scalp [Figure 1a]. Laboratory tests revealed elevated levels of LDH (498 U/l) and soluble interleukin-2 receptor (2410 U/ml). Anti-human T-lymphotropic virus-1 antibody was negative. A biopsied specimen from a pigmented patch showed mild epidermal hyperplasia with a few epidermotropic lymphocytes. Fontana-Masson stain showed increased basal pigmentation in the overlying epidermis. Another specimen from the nodule demonstrated prominent epidermotropism with many microabscesses, and massive lymphocytic infiltration with atypical nuclei and mitotic figures in the dermis [Figure 1b]. The majority of these lymphocytes showed CD3+, CD4+, CD8–, and CD30+, though anaplastic lymphoma kinase (ALK)-1 was negative [Figure 1c]. Southern blot analysis of skin nodules and lymph nodes using T-cell receptor β-chain probes demonstrated an identical monoclonal band. Bone marrow examination did not show infiltration of atypical lymphocytes. After treatment with systemic chemotherapy (cyclophosphamide, doxorubicin, vincristine and prednisolone), the cutaneous nodules disappeared and the enlarged superficial lymph nodes became impalpable. In contrast, a number of small, whitish papules on the trunk became evident [Figure 2a]. Histological examination showed a cystic structure lined by a few layers of stratified epithelium, containing lamella keratinous materials [Figure 2b]. The cyst wall was neither surrounded nor infiltrated by atypical lymphoid cells.

Figure 1

(a) Hyperpigmented infiltrative plaques and ulcerative nodules on the trunk. Histology from a nodule showed prominent infiltration of tumor cells in the epidermis and dermis (b), which were positive for CD4 (c) (b: ×200, c: ×100)

Figure 2

(a) A number of small whitish cysts on the trunk. (b) Histology shows milium. (×200)

Most reported cases of mycosis fungoides (MF) associated with milia formation are folliculotropic type,[123] whereas cases other than folliculotropic MF, like the presented case, are extremely rare. Follicular MF exhibits comedo-like lesions, follicular hyperkeratosis, and acquired epidermal cysts,[4] however our case presented with typical milia, but not comedo-like lesions. Previous reports showed cases of milia development in regressing plaques of MF, however, whether milia were provoked by either treatments with topical nitrogen mustard and systemic acitretin, or the underlying disease process rather than the medications, is unknown. Secondary milia may develop due to the occlusion of eccrine ducts, in folliculotropic MF of follicular origins.[1] Unfortunately, we could not carry out a biopsy before chemotherapy, and thus the infiltration of lymphoma cells into the follicles or eccrine glands was unclear. However, milia formation is rarely induced even in non-folliculotropic type MF.