A 71-year-old man presented with numerous pruritic seborrheic keratoses, with an eruptive onset over the course of 3 months. At presentation, he was also found to have hypopigmented tumors diffusely scattered throughout his body that were found to be mycosis fungoides on histologic examination. A theory regarding the pathophysiology of the development of eruptive seborrheic keratoses in the presence of mycosis fungoides is briefly discussed and 10 previous case reports of the Leser-Trélat sign in the setting of mycosis fungoides are reviewed.

Psoriasis is a complex, chronic immune-mediatedinflammatory disease that most commonly presentsas well-demarcated erythematous plaques withmicaceous scale, affecting roughly 3-4% of the USpopulation [1-4]. Clinically, lesions are often welldemarcatedthick, scaly, erythematous plaques,characteristically located on the extensor surfaces,such as elbows and knees [1]. In most cases, clinicalimpression is sufficient to diagnose psoriasis. However,sometimes psoriasis can mimic other cutaneousdisorders and biopsy may be warranted to discoverthe diagnosis. We report an unusual presentation ofpsoriasis clinically mimicking mycosis fungoides.

Folliculotropic mycosis fungoides (MF) is a distinct subset of cutaneous T cell lymphoma (CTCL). The disease is typically marked by an aggressive course and is often recalcitrant to skin-direct therapy. We report a case of an 83-year-old woman with folliculotropic MF characterized by erythematous, scaly plaques on the forehead along with poliosis and alopecia of the right medial eyebrow.

Hypopigmented mycosis fungoides (HMF) is an uncommon form of cutaneous T-cell lymphoma. It can be seen in children and is usually mistaken for eczema, vitiligo, or progressive macular hypomelanosis, clinically and histopathologically. We present a boy with HMF confirmed by histopathology. The patient had a course with slow clinical progression without Sezary syndrome.

Mycosis fungoides (MF) is the most common type of cutaneous T-cell lymphoma. Mycosis fungoides classically presents in the skin as patches, plaques, tumors, or erythroderma, progressing to involve the lymph nodes and peripheral blood. The many clinical variants, with different histologic patterns, and the subtle early clinical and histologic changes may delay early diagnosis and present a diagnostic challenge for clinicians. The greatest challenge in diagnosis is the pre-mycotic stage, which may closely resemble eczematous or psoriasiform dermatitis clinically and histologically. The persistence of lesions and inadequate response to treatment are the first warning signs. Later stages of MF have a poor prognosis with poor therapeutic response and fatal outcome. We describe a 72-year-old man, who presented with a two-year history of an unusual eruption, which started on the abdomen, around the waistline, and gradually spread to involve his back, trunk, and buttocks. Clinically, the skin eruption presented as tiger-like stripes. The diagnosis was confirmed after histopathologic examination. The patient was treated with NB-UVB phototherapy with marked improvement.

Acanthosis nigricans maligna (ANM) is a paraneoplastic phenomenon most commonly associated with visceral adenocarcinoma, in particular, gastric adenocarcinoma. Clinically, AMN is characterized by rapidly progressive symmetrical skin thickening and hyperpigmentation of the intertriginous areas with peripheral acrochorda. The diagnosis is made by a detailed medical work-up for occult malignancies with particular emphasis on endocrinological diseases. We report a 67-year-old man that presented clinically with acanthosis nigricans, in which a subsequent diagnosis of mycosis fungoides was made.

Milia en plaque (MEP) is an uncommon skin condition identified as retroauricular confluent milium by Boulzer and Fouqet in 1903 [1]. It can be mistaken for other dermatoses like Favre-Racouchot nodular elastosis, steatocystoma multiplex, and nevus comedonicus. Milia en plaque can either be primary or secondary and is typically benign, often triggered by dermatological procedures like cryotherapy, as reported in this journal. In some cases, MEP can arise as a secondary manifestation of other diseases, including folliculotropic mycosis fungoides (FMF). Despite this association, there are few documented cases in the literature. Herein, we present a patient in whom MEP served as the initial clinical presentation of FMF; the treatment involved oral retinoids and phototherapy. Furthermore, we highlight distinctive features of both conditions. It is important to emphasize that early diagnosis and treatment of FMF are vital for the patient's quality of life. The presence of MEP can serve as a valuable indicator for identifying it.

Mycosis fungoides (MF) is the most common type of cutaneous T-cell lymphoma, although it has many clinicopathological variants. Zosteriform MF is an extremely rare variant characterized by dermatomal distribution. To date, only six patients with zosteriform MF have been reported. We report a 57-year-old man with tumor-stage zosteriform MF localized on the left T4, T7-8, and bilateral L4 dermatomes for seven years after the first visit. Local skin-target therapy radiotherapy effectively led to complete remission, which was maintained with a combination of oral etretinate (30mg/day) and narrow-band ultraviolet B phototherapy. No other reports exist of zosteriform MF occurring in multiple dermatomes. We reviewed the literature to add to our understanding of the nature of rare variants of MF and discuss therapeutic options for zosteriform MF.

Mycosis fungoides (MF) is characterized by a clonal proliferation of skin-homing mature T cells with special predilection for involving the epidermis. Folliculotropic and syringotropic MF typically present with erythematous papules, patches, and plaques, with punctate accentuation that is folliculocentric in the former. We report a 67-year-old woman, with an extensive history of allergic contact dermatitis, who was referred to the Mohs surgery clinic with a large pink plaque extending from the nasal bridge to the right upper medial cheek concerning for basal cell carcinoma. An outside punch biopsy showed benign basaloid follicular neoplasm. The patient was found to also have indurated erythematous plaques of the bilateral upper arms and erythematous scaly patches of bilateral arms and legs, abdomen, lateral trunk, buttocks, and groin. Owing to concern for possible cutaneous lymphoma, punch biopsies were performed which revealed the diagnosis of folliculotropic and syringotropic MF. Of note, folliculotropic and syringotropic MF are often, but not uniformly, characterized by a more aggressive disease course. This case highlights the importance of a high index of suspicion and awareness of all clinical and histopathologic pitfalls to avoid misdiagnosis of MF.