Synchronous Occurrence of Mycosis Fungoides, Diffuse Large B Cell Lymphoma and Acute Myeloid Leukemia

"Missed" Diagnosis of Mycosis Fungoides: A Case Report

Mycosis fungoides (MF) is the most common subtype of primary cutaneous T-cell lymphoma characterized by malignant proliferation of T cells with epidermotropism in the skin. MF has an indolent course, presents as erythematous scaly patches or plaques, and may progress to generalized erythroderma, cutaneous tumors, or extracutaneous invasion. MF is often misdiagnosed at early stages due to nonspecific clinical findings. Patients with MF are at high risk for developing secondary malignancies, including hematological malignancies. We hereby report a case of MF misdiagnosed and associated with underlying diffuse large B-cell lymphoma.

Mycosis Fungoides and Associated Malignancies in a Dutch Nationwide Retrospective Cohort Study

The prognosis of patients with mycosis fungoides is variable. As the current literature is scarce and shows mixed results this study investigates the incidence of other primary malignancies in mycosis fungoides patients. A retrospective, nationwide, population- based cohort study was performed with patients with mycosis fungoides between 2000 and 2020 in The Netherlands. All histopathology reports were requested from the Nationwide Network and Registry of Histo- and Cytopathology and screened for other primary malignancies. Lifelong incidence rates were used to compare the incidence of malignancies in mycosis fungoides patients and the general population. In total 1,024 patients were included with a mean follow-up of 10 years (SD 6). A total of 294 cases of other primary malignancies were found with 29% of the mycosis fungoides patients developing at least 1 other primary malignancy. Only cutaneous (odds ratio [OR] 2.54; CI 2.0-3.2) and haematological malignancies (OR 2.62; CI 2.00-3.42) had a statistically significant higher incidence than the Dutch population overall. Mycosis fungoides patients have a significantly increased risk of developing melanomas (OR 2.76; CI 2.11-3.59) and cutaneous squamous cell carcinomas mycosis fungoides (OR 2.34; CI 1.58-3.45). This study shows no association between mycosis fungoides and other solid organ tumours; however, such patients are significantly at risk of developing other haematological and cutaneous malignancies. Clinicians should be aware of this increased risk.

Concurrent Subcutaneous Panniculitis-like T-Cell Lymphoma and B-Cell Acute Lymphoblastic Leukemia in 2 Pediatric Patients

Subcutaneous panniculitis-like T-cell lymphoma is a cutaneous lymphoma characterized by CD8+ T-cell infiltrate in the subcutis that is rare in children. Acute lymphoblastic lymphoma is the most common pediatric malignancy and often presents with fevers and pancytopenia. Herein, we report 2 pediatric patients presenting with subcutaneous panniculitis-like T-cell lymphoma and B-cell acute lymphoblastic lymphoma, distinct hematologic malignancies arising from different lymphoid lineages, with no identifiable germline cancer predisposition.

A Rare Case of Cutaneous T-Cell Lymphoma Accompanied by Acute Monoblastic Leukemia and Diffuse Large B-Cell Lymphoma

A 70-year-old female was referred for brown-to-gray colored papules and nodules on her lower legs. She had been diagnosed with diffuse large B-cell lymphoma (DLBCL) in her stomach, and myelodysplastic syndrome (MDS) by bone marrow biopsy. Three years after complete remission of DLBCL, she experienced DLBCL recurrence in her small bowel and was hospitalized. MDS had been stationary, but during the treatment of DLBCL, her laboratory findings suggested signs of leukemia. Bone marrow biopsy was done, and acute monoblastic leukemia (AMoL) was diagnosed. After 1 cycle of chemotherapy for AMoL, skin lesions developed, and her skin biopsy showed cutaneous T-cell lymphoma (CTCL). Terminal deoxynucleotidyl transferase staining and CD123 staining were negative, and bone marrow re-biopsy conducted after the skin lesion developed still showed monoblastic proliferation. Whether the CTCL represented with an AMoL lineage switch could not be completely proved due to the absence of molecular or clonal marker evaluations, but the possibility of coexistence of three different malignancies was higher. During treatment, a neutropenic fever developed, and the patient died due to sepsis. We herein report a rare case of CTCL accompanied by AmoL and DLBCL.