Pseudolymphomatous folliculitis presenting with multiple nodules

ARTICLE

Auteur(s) : Motonobu Nakamura, Kenji Kabashima, Yoshiki Tokura

Department of Dermatology, University of Occupational and Environmental Health, 1-1 Iseigaoka, Yahatanishi-ku, Kitakyushu 807-8555, Japan

Pseudolymphomatous folliculitis (PLF) was first described in 1986 as a distinct variant of pseudolymphoma, characterized by a dense lymphoid infiltrate accompanied by hyperplastic hair follicles [1]. Clinically, PLF is typified by a solitary dome-shaped or flat-elevated nodule, located on the face, scalp and trunk. We report herein a case of multiple nodules on the face and the neck with histologically diffuse lymphoid cell infiltration around an activated pilosebaceous unit. To our knowledge, this is the first report of PLF presenting with multiple nodules.

A 35-year-old Japanese woman was referred to us for evaluation of a 5-year history of multiple reddish to brownish dome-shaped nodules on the face (figure 1A) and neck (figure 1B). Neither topical corticosteroid ointment nor oral anti-histamine medicine prescribed at another hospital had been effective for the nodules. She felt slight pruritus and no pain on the lesions. There was no history of recent insect bites or drug intake.

After obtaining written informed consent from the patient, we took a skin biopsy specimen from a nodule on the cheek. The specimen showed a dense lymphocytic infiltration from the dermis to subcutaneous tissue, accompanied by a dilated, activated pilosebaceous unit (figure 1C). Hair follicles were distorted, hyperplastic and filled with keratin plugs. The infiltrate was composed of small lymphoid cells, histiocytic cells and pleomorphic stromal cells (figure 1D). There was no fungus element in the dilated follicles as assessed by PAS staining. Some lymphocytes infiltrated into the hair follicles. Mitotic figures of lymphocytes were rarely identified. The overlying epidermis was flattened without any lymphocytic infiltration into the epidermis.

An immunophenotypic study showed a vast majority of lymphoid cells were positive for CD3 and CD4, and small numbers of CD8 positive and CD30 positive cells were present. A considerable number of CD68 positive histiocytic cells and S-100- and CD1a-positive Langerhans cells or indeterminate cells were intermingled with the infiltrate. Although the patient came from the pandemic region of human T-cell leukemia/lymphoma virus 1 (HTLV-1), blood examination revealed that she was negative for anti HTLV-1 antibodies. Based on the clinical and histopathological features of the skin lesions, a diagnosis of PLF was made.

Although treatment with triamcinolone acetonide injection has been reported to be very effective for PLF [2], the patient refused to take a local injection therapy. Since neither topical tacrolimus (0.1%) ointment, narrow band-ultraviolet B (UVB) irradiation nor systemic weekly administration of interferon-γ (1 million unit/week × 4 weeks) was effective for our patient, systemic administration of oral cyclosporine (2.5 mg/kg daily) was initiated. The eruption responded to cyclosporine and subsided in size substantially.

Since the first description of PLF in 1986 [1], cases of PLF have been reported all over the world [2-5]. Kazakov et al. [5] reviewed their 42 cases of PLF and showed that there was an equal sex distribution and the age at diagnosis ranged widely, from 8 to 82 years. All the cases had solitary nodules which were surgically removed without any recurrence in the follow-up. Although the multiple-nodular lesions in our case were difficult to remove surgically, they responded well to oral cyclosporine administration. It is considered that the nodules in our case occurred as a result of lymphomatous inflammatory reactions to hair follicle remnants, which might be on the same spectrum as lupus miliaris disseminatum faciei or inflammatory acne.

Acknowledgements

References

2 Lee HW, Ahn SJ, Lee MW, Choi JH, Moon KC, Koh JK. A case of pseudolymphomatous folliculitis. J Eur Acad Dermatol 2006; 20: 230-2.

3 Kibbi AG, Scrimenti RJ, Koenig RR, Mihm MC. A solitary nodule of the left cheek. Arch Dermatol 1988; 124: 1271-6.

4 Arai E, Okubo H, Tsuchida T, et al. Pseudolymphomatous folliculitis: a clinicopathologic study of 15 cases of cutaneous pseudolymphoma with follicular invasion. Am J Surg Pathol 1999; 23: 1313-9.

5 Kazakov DV, Belousova IE, Kacerovska D, et al. Hyperplasia of hair follicles and other adnexal structures in cutaneous lymphoproliferative disorders. A study of 53 cases, including so-called pseudolymphomatous folliculitis and overt lymphomas. Am J Surg Pathol 2008; 32: 1468-78.