Mycosis Fungoides and Granulomatous Slack Skin: A Single Entity With Distinct Clinical Phenotypes

ABSTRACT

Granulomatous cutaneous T-cell lymphoma includes mycosis fungoides with significant granulomatous inflammation (GMF) and granulomatous slack skin (GSS), listed in the WHO classification as a subtype of mycosis fungoides (MFs). 1 These overlapping entities have shared clinical and histopathologic features which can present a diagnostic challenge. The dominance of the granulomatous infiltrate and the often sparse lymphocytic infiltrate frequently with minimal cytological atypia are features that distract from the correct diagnosis, even when raised by the clinician. We describe the clinical and histopathologic characteristics of 3 cases of granulomatous cutaneous T-cell lymphoma, illustrate the close clinical and pathologic relationship between GMF and GSS and emphasize the diagnostic difficulties that the granulomatous infiltrate can present. Furthermore, we demonstrate, for the first time, considerable elastolysis in a significant proportion of classical (Alibert-Bazin) MF lesions and therefore postulate that the differences observed between GMF and GSS are one of degree and secondary to their anatomic location rather than reflecting meaningful separate entities.

A Rare and Isolated Presentation of Primary Cutaneous Anaplastic Large Cell Lymphoma on the Breast

Primary cutaneous anaplastic large-cell lymphoma (PC-ALCL) is a subtype of non-Hodgkin lymphoma belonging to the CD30+ spectrum of lymphoproliferative disorders. It constitutes the second most prevalent category within cutaneous T-cell lymphomas (CTCL), encompassing approximately 25% of cases. This disorder is characterized by its exclusive cutaneous involvement and favorable overall prognosis. Patients typically present with reddish-brown nodules, which may evolve into ulcers. Although some cases experience regression, complete resolution is uncommon. While most lesions manifest on the extremities, followed by the head and neck, the breast region may rarely be affected by PC-ALCL. Distinctions between anaplastic lymphoma kinase (ALK)-positive and ALK-negative subtypes have been documented in breast presentations, often associated with breast implants. In this context, we present an isolated PC-ALCL instance in a 26-year-old woman with no history of breast implants.