A case of nodal marginal zone lymphoma with hypersensitivity to mosquito bites as initial symptom

Eosinophilic Dermatosis of Hematologic Malignancy: Emerging Evidence for the Role of Insect Bites-A Retrospective Clinico-Pathological Study of 35 Cases

Background/Objectives: Eosinophilic dermatosis of hematologic malignancy (EDHM) is a rare cutaneous disorder associated with various hematologic malignancies, most commonly chronic lymphocytic leukemia. Detailed clinicopathologic studies of EDHM are lacking and the pathogenesis remains enigmatic. Initially thought to be a hypersensitivity reaction to insect stings, subsequent reports have challenged this understanding. The prognostic implications of EDHM remain unclear. Methods: A retrospective clinicopathologic study was performed on patients diagnosed with EDHM. Hematologic and dermatologic data were reviewed. Histologic specimens were re-evaluated and lesions were classified into acute/subacute, fully developed, and chronic/regressing. Results: The study included 35 patients. In 80% of these patients, EDHM was diagnosed after the hematologic disorder. Approximately 45% of the cohort experienced hematologic disease progression or relapse, while 65% required therapeutic intervention during the course of their hematologic disease. In total, 15/19 CLL patients had non-mutated IgHV, a marker of a more aggressive hematologic disease course. Dermatologic lesion morphology was heterogeneous, with most lesions occurring on exposed areas, and a significant 94% of patients demonstrated lesion seasonality. Histopathologic findings were consistent with features typically associated with insect bites. In addition, examination of lesions at different chronological stages revealed substantial similarities with Wells syndrome. Conclusions: Our findings support the potential role of insect bites in triggering EDHM in the context of adaptive immune dysfunction. EDHM may be associated with a more aggressive disease course or may be a marker of disease progression. The observed co-occurrence of features typical of Wells syndrome in EDHM patients suggests that these conditions are part of a spectrum of disorders that vary in clinical expression.

Eosinophilic dermatosis of hematologic malignancy in patients with chronic lymphocytic leukemia/non-Hodgkin's B lymphoma: a single center prospective clinico-pathological study

Background

The pathogenesis of eosinophilic dermatosis of hematologic malignancy (EDHM) is poorly understood. Previously thought to be a hypersensitivity reaction to insect bites, immune dysregulation and cytokine imbalance are now thought to be responsible. Its prognostic significance is unclear.

Objective

To describe the clinical, pathological and immunological findings in a series of oncohematological patients with EDHM.

Methods

An observational prospective cohort study of oncohematological patients receiving a diagnosis of EDHM between April 2017 and December 2018.

Results

A total of 15 patients with EDHM (10 females and 5 males) were identified among 422 oncohematological patients. Disease presentation varied from firm erythematous papules to more polymorphic presentations. The lesions were most prevalent on the exposed sites, 8/15 patients recalled an insect bite. Lesion seasonality was reported in 13/15 patients. IgE levels were elevated in six patients, circulating IL-4 and IL-5 were within a normal range. Twelve out of 15 patients developed skin manifestations after chemotherapy. The infiltrate could be eosinophil-rich or lymphocytic-rich. Interestingly, the histopathologic findings were in accordance with arthropod bites.

Conclusion

A role for insect bites in EDHM is supported by our findings. EDHM may be related to aggressive hematologic disease.

Primary cutaneous anaplastic large-cell lymphoma with DUSP22-IRF4 rearrangement following insect bites

Primary cutaneous anaplastic large‐cell lymphoma (pC‐ALCL) is distinguished from systemic anaplastic large‐cell lymphoma (S‐ALCL) with cutaneous involvement. Although pC‐ALCL is a unique entity with different genetics, clinical characteristics, and prognosis, its causes are unknown. Herein, we report the case of a Chinese woman with a 4‐month history of a gradually enlarged ulcerative mass in her right forearm following an unidentified insect bite. Biopsy revealed an extensive infiltrate with patches of large anaplastic lymphoid cells. These cells were immunohistochemically positive for CD45, CD30, and TIA‐1 and negative for CD2, CD3, CD4, CD5, CD20, CD7, CD8, and ALK‐1. DUSP22‐IRF4 rearrangement was detected; on the other hand, TP63 rearrangement was not observed by fluorescence in situ hybridization (FISH). No Epstein‐Barr virus‐encoded small RNAs (EBERs) were detected by ISH. Rearrangement of monoclonal TCR gene was found using BIOMED‐2 polymerase chain reaction. No abnormality was found on the subsequent positron emission tomography‐computed tomography (PET‐CT) scan. After five cycles of cyclophosphamide + doxorubicin + vincristine + prednisolone (CHOP) chemotherapy, the patient achieved complete remission. This is the first report of a unique pC‐ALCL with DUSP22‐IRF4 rearrangement following an insect bite other than S‐ALCL involving the skin.

Hypersensitivity to mosquito bites: A versatile Epstein-Barr virus disease with allergy, inflammation, and malignancy

Hypersensitivity to mosquito bites (HMB) is a rare disease characterized by transient intense skin reaction and systemic inflammation. Clinical presentation of HMB resembles other mosquito allergic responses, and it can also be difficult to clinically distinguish HMB from other severe allergic reactions. However, a distinctive pathophysiology underlies HMB. HMB belongs to a category of Epstein-Barr virus (EBV)-associated natural killer (NK) cell lymphoproliferative disorders (LPD). Hence, HMB may progress to systemic diseases, such as hemophagocytic lymphohistiocytosis, chronic active EBV disease, and EBV-associated malignancies. A triad of elevated serum IgE, NK lymphocytosis, and detection of EBV DNA in peripheral blood is commonly observed, and identification of EBV-infected NK cells usually facilitates the diagnosis. However, the effective treatment is limited, and its precise etiology remains unknown. Local CD4+ T cell proliferation triggered by mosquito bites appears to help induce EBV reactivation and EBV-infected NK-cell proliferation. These immunological interactions may explain the transient HMB signs and symptoms and the disease progression toward malignant LPD. Further research to elucidate the mechanism of HMB is warranted for better diagnosis and treatment of HMB and other forms of EBV-associated LPD.

Mosquitoes, Infectious Diseases, and Cancer: A Connection to Study?

Mosquitoes (Diptera: Culicidae) are vectors of pathogens and parasites of great medical and veterinary relevance. The possible association between mosquitoes, infectious diseases, and cancer has been investigated. Despite its potential importance, there is a severe lack of research data on the topic. Herein, current knowledge, tenuous links, and related challenges on the topic were examined, grouping information under four major hypotheses. The first hypothesis is that the infection of mosquito-vectored parasites, with special reference to Plasmodium spp., may lead to cancer. The International Agency for Research on Cancer stated that being infected by Plasmodium falciparum malaria in holoendemic areas is probably carcinogenic to humans (group 2A), considering that P. falciparum infection is able to reactivate the Epstein–Barr virus, leading to endemic Burkitt lymphoma. Also, malaria was recently associated with a cancer incidence increase in the United States. The second hypothesis is that cancer may be spread directly through mosquito bites: Aedes mosquitoes transfer viable tumor cells among vertebrate hosts, even if no plausible mechanisms for these cells to develop cancer into the new host are known. As the third hypothesis, mosquito bites may lead to hypersensitivity, resulting in cancer. Hypersensitivity stimulated by mosquito bites links allergy, oncogenesis, and the Epstein–Barr virus, causing Burkitt lymphoma. One may argue that pathogens transmitted by mosquitoes, such as viruses, may be carcinogenic. However, no detailed research evidences are available to substantiate this last hypothesis. However, despite the intriguing hypotheses outlined above, there is a severe lack of data showing cancer development in organisms exposed to mosquitoes transmitting parasites or pathogens. According to One Health criteria, this benchmark is aimed to outline major questions on this public health issue, stressing the need of multidisciplinary research and discussion.