Mycosis fungoides presenting as annular erythema

Annular skin tumors and lymphoproliferative diseases

Determining the shape of a skin lesion may provide a diagnostic clue in dermatology practice, more commonly for inflammatory diseases but also for skin tumors. The annular formation may develop by diverse mechanisms in skin tumors. Annular lesions may occur from the onset of the tumor as sparing the central area or depression and/or ulceration in the center of the tumor or outward expansion of the primary lesion. Clustering of multiple papulonodular lesions sparing the central area or relatively independent processes acting on the central and peripheral components of the tumor may also result in an annular appearance. We have explored a wide variety of benign and malignant skin tumors and lymphoproliferative diseases forming an annular shape.

Annular skin tumors and lymphoproliferative diseases

Determining the shape of the skin lesion may provide a diagnostic clue in dermatology practice, more commonly for inflammatory diseases but also for skin tumors. The annular formation may develop by diverse mechanisms in skin tumors. Annular lesions may occur from the onset of the tumor as sparing the central area or depression and/or ulceration in the center of the tumor or outward expansion of the primary lesion. Clustering of multiple papulonodular lesions sparing the central area or relatively independent processes acting on the central and peripheral components of the tumor may also result in an annular appearance. We have explored a wide variety of benign and malignant skin tumors and lymphoproliferative diseases forming an annular shape.

Is it mycosis fungoides? A comprehensive guide to reaching the diagnosis and avoiding common pitfalls

Mycosis Fungoides (MF) is known as 'the great mimicker' due to its capacity to emulate several dermatoses, both in the clinic and on histology. This often leads to the diagnosis being missed or delayed, which consequently leads to poorer prognosis. For a timely diagnosis, it is crucial that the physician is aware of the various clinical and histological presentations of MF, as well as the proper diagnostic protocols. In the current review, we concisely encapsulate all the variants of MF as well has the conditions it mimics clinically and histologically. Through this, we aim to provide clinicians with a holistic picture of MF and help them determine when to suspect this disease and steps to take in order to nail the diagnosis.

Mycosis fungoides: A mimicker of benign dermatoses

Mycosis fungoides, the most common primary cutaneous lymphoma, may present with a broad spectrum of clinical features. As both clinical and dermatopathological findings in mycosis fungoides occasionally closely imitate other dermatoses, correct diagnosis may be a challenge both for clinicians as well as dermatopathologists. As a consequence, diagnosis of cutaneous lymphoma may be initially missed and, therefore, prompt and adequate therapeutic measures delayed. Hence, the purpose of our article was to give an overview of hitherto published “mimickers” of mycosis fungoides with a review of its diverse clinical features to alert the clinicians about the wide spectrum of this dissimulating disease. By integrating our own encountered atypical cases of mycosis fungoides we provide a comprehensive illustrated histological and moleculargenetic workup thereof and thereby critically revise the different available diagnostic tools of daily routine. Finally, we derive a practical algorithm to obtain the correct diagnosis even in such ambiguous cases of mycosis fungoides.

Mycosis fungoides mimicking an annular erythema

Diagnosis of mycosis fungoides (MF) can be difficult due to its highly variable presentation and the sometimes nonspecific nature of the histological and molecular findings. MF classically presents as patches, plaques and tumours as originally described by Alibert and Bazin, but many other clinical presentations may occur, often mimicking other inflammatory conditions. We report a case of MF presenting as typical centrifugal annular erythema.

Mycosis fungoides: a dermatological masquerader

Mycosis fungoides (MF), a low-grade lymphoproliferative disorder, is the most common type of cutaneous T-cell lymphoma. Typically, neoplastic T cells localize to the skin and produce patches, plaques, tumours or erythroderma. Diagnosis of MF can be difficult due to highly variable presentations and the sometimes nonspecific nature of histological findings. Molecular biology has improved the diagnostic accuracy. Nevertheless, clinical experience is of substantial importance as MF can resemble a wide variety of skin diseases. We performed a literature review and found that MF can mimic >50 different clinical entities. We present a structured framework of clinical variations of classical, unusual and distinct forms of MF. Distinct subforms such as ichthyotic MF, adnexotropic (including syringotropic and folliculotropic) MF, MF with follicular mucinosis, granulomatous MF with granulomatous slack skin and papuloerythroderma of Ofuji are delineated in more detail.

Mycosis fongoïde à type d’érythème annulaire centrifuge

INTRODUCTION

Mycosis fungoides is a lymphoma, the classical clinical form of which involves erythematosquamous lesions. However, it can present various atypical aspects: hyper pigmentation or hypo pigmentation, suggestive of pyoderma gangrenosum or ichtyosis. We report a case of mycosis fungoides, unusual in its presentation in the form of centrifugal annular erythema.

OBSERVATION

A 78 year-old man had developed a parapsoriasis in plaques for more than 20 years. In May 2002 he consulted because of the recent infiltration of one of the plaques, without concomitant pruritus. The clinical examination revealed 3 lesions of the popliteal groove of the right groin and the left cheek suggestive of centrifugal annular erythema. Histology, revealing Pautrier microabscesses, was compatible with the diagnosis of mycosis fungoides. Evolution was marked by the spontaneous regression of the plaque on the face and remission of the other two plaques after local treatment with chloromethin and topical corticosteroids. Nevertheless, new plaques appeared despite continued treatment, combined with PUVA therapy sessions.

DISCUSSION

When searching the literature, we only found one other case of mycosis fungoides, the clinical aspect of which was a centrifugal annular erythema, but in which the histological examination confirmed the diagnosis of mycosis fungoides. Our case report is also unusual in the clinical regression of the lesion on the face, without treatment; this has only been reported in two cases. Mycosis fungoides can appear in various clinical forms. The centrifugal annular erythema form is rare, but this diagnosis should be evoked.