Primary cutaneous T-cell lymphoma: a review of the most common entities with focus on recent updates

Skin-directed radiotherapy for primary cutaneous T-cell lymphomas

PURPOSE

To evaluate the efficacy and toxicities of skin-directed radiotherapy (RT) in primary cutaneous T-cell lymphoma (CTCL).

MATERIALS AND METHODS

We retrospectively analyzed 57 CTCL lesions treated with skin-directed RT between January 2000 and December 2022. Lesions were categorized into three distinct groups: early-stage disease treated with local RT, advanced-stage disease treated with local RT, and advanced-stage disease treated with total skin electron beam therapy (TSEBT). Treatment outcomes, including response rates, recurrence patterns, and local progression probability, were assessed for each group.

RESULTS

Mycosis fungoides (MF) constituted 90.9% of the advanced-stage pathologies, while CD4+ primary cutaneous small/medium T-cell lymphoproliferative disorder was common in the early stage lesions (55%). Median RT doses were 30.6 Gy, 27 Gy, and 32 Gy for the local RT with early stage, the local RT with advanced stage, and TSEBT with advanced stage, respectively. The complete response rates were high across the groups: 95.5%, 70.8%, and 90.9%, respectively. Seven local recurrences (29.2%) occurred in the local RT group with advanced stage, while seven patients (63.6%) in the TSEBT group experienced local failure. All recurrences were observed in lesions and patients with MF. Acute toxicities were mainly grade 1 or 2, with no grade 3 or higher events. No significant association between RT dose and local progression rates in MF lesions was found.

CONCLUSION

Skin-directed RT in CTCL is effective for local control and well-tolerated with less toxicity.

Regulation of newly identified lysine lactylation in cancer

Metabolic reprogramming is a typical hallmark of cancer. Enhanced glycolysis in tumor cells leads to the accumulation of lactate, which is traditionally considered metabolic waste. With the development of high-resolution liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS), the lactate-derived, lysine lactylation(Kla), has been identified. Kla can alter the spatial configuration of chromatin and regulate the expression of corresponding genes. Metabolic reprogramming and epigenetic remodeling have been extensively linked. Accumulating studies have subsequently expanded the framework on the key roles of this protein translational modification (PTM) in tumors and have provided a new concept of cancer-specific regulation by Kla.

Folliculotropic mycosis fungoides associated with follicular mucinosis: A case report and mini review

Key Clinical Message

F-MF is a rare non-classic variant of MF. In the case of hair loss, this should be a diagnostic consideration. The essence of the diagnosis of F-MF is a careful medical history, physical examination, and a combination of immunohistological and molecular analyses (Cureus. 2022; 14:e21231, Ann Saudi Med. 2012; 32:283, Oman Med J. 2012; 27:134, Int J Dermatol. 2016; 55:1396, Saudi Med J. 2018; 39:994 and Case Rep Oncol. 2018; 11:436).

Abstract

Mycosis fungoides (MF) is a primary cutaneous T-cell lymphoma with multiple subtypes. Follicular MF (F-MF) is a non-classic variant of MF. Histological features entail folliculotropism and damage of the epithelium lining of the hair follicles with or without mucin deposition. A 52-year-old male patient complained of recurrent skin lesions on the scalp over 8 months. The lesions appeared suddenly, enlarged over time, and became itchy. A skin punch biopsy was performed. Histological features included mucin deposits in the epithelium of the hair follicles and dense, predominantly perifollicular atypical lymphocytes infiltrating the follicular epithelium. The lymphoid cells were composed of CD3-positive T cells (CD4/CD8-positive T cells) with a shift in favor of the former. The case was diagnosed as F-MF on an immunohistological basis. The diagnosis of F-MF is often difficult for dermatologists and dermatopathologists alike. Not only clinicopathological correlations but also immunohistochemical and molecular analysis are required.