INTRODUCTION

Mycosis fungoides is a primary cutaneous T-cell lymphoma characterized by a slow progression through patch, plaque, and tumor stages [1–3]. In its early phases, MF frequently resembles benign inflammatory dermatoses, making diagnosis challenging even for experienced clinicians [4,5].

The subtle and variable clinical presentation, along with histopathologic overlap with chronic dermatitis, commonly leads to misdiagnosis and delayed treatment [4]. International literature reports diagnostic delays ranging from months to several years, often impacting long-term outcomes [2,6,7].

In our setting, patients frequently receive multiple prior treatments for presumed chronic eczema, sometimes for extended periods, before a biopsy is considered. This study presents our institutional experience with patients whose initial diagnosis was eczema but were later confirmed to have MF.

MATERIALS AND METHODS

This retrospective study included all patients diagnosed with MF from 2016 to 2024 at the Department of Dermatology, University Clinical Center of Kosovo. The inclusion criteria were:

1. Histopathologic confirmation of MF [1,4]
2. Initial misdiagnosis as eczema or chronic dermatitis [5].
3. Available follow-up data:

Biopsies were reviewed by dermatopathologists and analyzed by immunohistochemistry (CD3, CD4, CD8, CD30, TCR) [4]. Data extracted included demographic information, clinical characteristics, duration before diagnosis, staging, and patient outcomes.

According to WHO-EORTC classification and staging recommendation [1,8].

Descriptive statistics were performed using standard analytical methods.

RESULTS

Sixteen patients, 14 males and two females, fulfilled the inclusion criteria. Demographic characteristics and clinical features are detailed in Tables 1 and 2 respectively. Most had been treated for months with topical therapies for presumed eczema. Initial symptoms and previous treatments are shown in Tables 3 and 4. Twelve patients required more than one dermatology visit before biopsy was performed. Table 5 summarizes immunohistochemical profiles. One case progressed to the tumor stage and subsequently died from complications.

	Table 1: Demographic characteristics of patients diagnosed with MF initially treated as eczema.
	Table 2: Clinical features and disease stage at diagnosis.
	Table 3: Initial symptoms reported.
	Table 4: Previous treatments before MF diagnosis.
	Table 5: Immunohistochemical profile.

DISCUSSION

Our results show that misdiagnosis of MF as chronic eczema remains a significant clinical challenge [5]. Prolonged use of topical corticosteroids may improve lesions temporarily, masking underlying malignancy and delaying biopsy.

In our cohort, the diagnostic delay averaged more than 12 months, consistent with international literature [2,7]. Repeated biopsies were necessary in some patients due to nonspecific early-stage histopathology [4].

The case with a family history of CLL highlights potential immunogenetic associations previously reported in the literature [3]. The fatal outcome in one patient underscores the importance of timely diagnosis.

These findings emphasize the need for greater clinical suspicion in cases of dermatitis unresponsive to appropriate therapy [8,9,10].

Early-stage MF frequently mimics chronic eczema, leading to delayed diagnosis and potential disease progression [11–13]. Dermatologists should maintain a high index of suspicion for MF in persistent or treatment-resistant dermatitis [14,15]. Early biopsy, appropriate immunohistochemistry, and clinicopathologic correlation are crucial for accurate and timely diagnosis in addition to therapeutic intervention [16].

REFERENCES

1.  Willemze R, Jaffe ES, Burg G, Cerroni L, Berti E, Swerdlow SH, et al. WHO-EORTC classification for cutaneous lymphomas. Blood. 2005;105:3768-85.

2.  Zackheim HS, McCalmont TH, Dean ML. Mycosis fungoides:diagnostic delay and disease progression. Arch Dermatol. 1999;135:451-5.

3.  Kempf W, Kazakov DV, Mitteldorf C. Eczematous mycosis fungoides:clinicopathologic features. J Cutan Pathol. 2018;45:327-35.

4.  Whittaker SJ, Marsden JR, Spittle M, Russell Jones R. Cutaneous T-cell lymphomas:diagnostic and therapeutic update. Br J Dermatol. 2016;174:296-310.

5.  Pulitzer M. Cutaneous T-cell lymphoma:update on diagnosis. Hematol Oncol Clin North Am. 2017;31:253-68.

6.  Olsen E, Vonderheid E, Pimpinelli N, Willemze R, Kim Y, Knobler R, et al. Revisions to the staging of mycosis fungoides and Sézary syndrome. Blood. 2007;110:1713-22.

7.  Willemze R. Familial cutaneous lymphoma:clinical perspectives. J Eur Acad Dermatol Venereol. 2019;33:621-8.

8.  Agar NS, Wedgeworth E, Crichton S, Mitchell TJ, Cox M, Ferreira S, et al. Survival outcomes in mycosis fungoides:an international study. J Clin Oncol. 2010;28:4730-9.

9.  Hodak E, Amitay-Laish I. Diagnostic pitfalls in early mycosis fungoides. Am J Dermatopathol. 2014;36:142-8.

10.  Scarisbrick JJ, Prince HM, Vermeer MH, Quaglino P, Horwitz S, Porcu P, et al. Prognostic factors and survival in MF:a multicenter study. Br J Dermatol. 2015;173:112-20.

11.  El Amraoui M, Hjira N, Ismaili N, Boui M, Senouci K. Neglected mycosis fungoides transformed into cutaneous CD30?T-cell lymphoma. Our Dermatol Online. 2021;12:88-9.

12.  Borowska K, Wasyłyszyn T. Mycosis fungoides as casus pro diagnosi. Our Dermatol Online. 2017;8:229-30.

13.  Borowska K, ZońB, Faryna J. A case report of small-plaque parapsoriasis. Our Dermatol Online. 2022;13:e48.

14.  CisońH, Woźniak Z, Białynicki-Birula R. Disseminated eczema or CTCL:Usefulness of high-frequency ultrasonography in the assessment of skin lesions of cutaneous T-cell lymphoma. Our Dermatol Online. 2024;15:160-3.

15.  Shanshal M. Dermatologic Emergencies CME Part II:Infections and infection-related complications. Our Dermatol Online. 2022;13:483-94.

16.  Bennouna N, Hali F, Chiheb S. UVB Phototherapy for sclerosing skin conditions –series of 10 cases. Our Dermatol Online. 2023;14:e28.