Medical management update: Non-Hodgkin lymphoma

snoRNAs in hematopoiesis and blood malignancies: A comprehensive review

Small nucleolar RNAs (snoRNAs) are noncoding RNA molecules of highly variable size, usually ranging from 60 to 150 nucleotides. They are classified into H/ACA box snoRNAs, C/D box snoRNAs, and scaRNAs. Their functional profile includes biogenesis of ribosomes, processing of rRNAs, 2'-O-methylation and pseudouridylation of RNAs, alternative splicing and processing of mRNAs and the generation of small RNA molecules like miRNA. The snoRNAs have been observed to have an important role in hematopoiesis and malignant hematopoietic conditions including leukemia, lymphoma, and multiple myeloma. Blood malignancies arise in immune system cells or the bone marrow due to chromosome abnormalities. It has been estimated that annually over 1.25 million cases of blood cancer occur worldwide. The snoRNAs often show a differential expression profile in blood malignancies. Recent reports associate the abnormal expression of snoRNAs with the inhibition of apoptosis, uncontrolled cell proliferation, angiogenesis, and metastasis. This implies that targeting snoRNAs could be a potential way to treat hematologic malignancies. In this review, we describe the various functions of snoRNAs, their role in hematopoiesis, and the consequences of their dysregulation in blood malignancies. We also evaluate the potential of the dysregulated snoRNAs as biomarkers and therapeutic targets for blood malignancies.

Delayed diagnosis of oral lymphoma: a case series

Lymphomas are the second most common neoplasm in the head and neck. The clinical and radiographic presentation of non-Hodgkin lymphoma in the oral cavity is non-specific and can be hard to differentiate from other common infectious or inflammatory conditions. We report four cases of lymphoma of the head and neck, which presented as odontogenic infection, osteomyelitis, or cutaneous infection, and subsequently led to a delay in provision of appropriate treatment. Correlation between clinical, radiographic and histological findings is essential in reaching an accurate diagnosis. It is important for clinicians to consider malignant lesions, such as lymphoma, in the differential diagnosis of pain, swelling, tooth mobility or radiographic radiolucencies. Clinicians should maintain a high level of suspicion for malignancy when inflammatory lesions fail to respond to normal modes of treatment.

EBV Association with Lymphomas and Carcinomas in the Oral Compartment

Epstein-Barr virus (EBV) is an oncogenic human herpesvirus infecting approximately 90% of the world's population. The oral cavity serves a central role in the life cycle, transmission, and pathogenesis of EBV. Transmitted to a new host via saliva, EBV circulates between cellular compartments within oral lymphoid tissues. Epithelial cells primarily support productive viral replication, while B lymphocytes support viral latency and reactivation. EBV infections are typically asymptomatic and benign; however, the latent virus is associated with multiple lymphomas and carcinomas arising in the oral cavity. EBV association with cancer is complex as histologically similar cancers often test negative for the virus. However, the presence of EBV is associated with distinct features in certain cancers. The intrinsic ability of EBV to immortalize B-lymphocytes, via manipulation of survival and growth signaling, further implicates the virus as an oncogenic cofactor. A distinct mutational profile and burden have been observed in EBV-positive compared to EBV-negative tumors, suggesting that viral infection can drive alternative pathways that converge on oncogenesis. Taken together, EBV is also an important prognostic biomarker that can direct alternative therapeutic approaches. Here, we discuss the prevalence of EBV in oral malignancies and the EBV-dependent mechanisms associated with tumorigenesis.

Oral Malignant Non-Hodgkin Lymphoma: A Retrospective Single-Center Study

This study aimed to retrospectively evaluate the incidence of oral non-Hodgkin lymphoma (NHL) in patients referred to the Academic Hospital of the Magna Graecia University of Catanzaro from 2002 to 2020. A retrospective single-center study was performed. Patients with a histologically confirmed diagnosis of oral NHL were included. Demographic data and clinical parameters were digitally recorded, focusing on the NHL-specific localization and symptomatology. The study sample was evaluated by analyzing descriptive statistics with absolute and relative frequencies. A total of 26 patients with intraoral NHL were identified with a progressive increase in NHL occurrence during the observation period. Clinical manifestations included swelling/mass (80.7%), eventually associated with pain and ulcerations. The most common localizations were in soft tissues: buccal mucosa (38.4%), tongue (19.2%), gingiva (11.5%), cheek (11.5%). Oral NHL is rare. Clinical manifestations were unspecific, so a misdiagnosis could occur. The extranodal B-cell form of oral NHL, particularly diffuse large B-cell lymphoma, was the most common frequent oral NHL in this southern Italian population, with a progressively increased occurrence in almost 20 years.

Oral manifestations of extranodal lymphomas - a review of the literature with emphasis on clinical implications for the practicing dentist

OBJECTIVE

Lymphoma is a heterogenous group of malignant tumours with proliferation of lymphoid cells or their precursors. Lymphomas in the head and neck region are usually found in Waldeyer's ring. Intraoral lymphomas are rare and the clinical presentation and roentgenological appearance may resemble other and benign conditions, entailing a risk for diagnostic delay. The objective of the present literature review was to identify subjective symptoms, clinical presentations and roentgenological appearances which should raise suspicion of lymphoma.

MATERIALS AND METHODS

The literature review identified 41 case series with head and neck lymphomas (n = 3880) and 384 case reports (n = 567 cases) of intraoral lymphomas. Information of demographics, clinical presentation, subjective symptoms and roentgenological appearance was registered.

RESULTS

The most common clinical presentation was a broad-based swelling or bulging mass with or without simultaneous ulceration, frequently with a relatively rapid growth pattern. Subjective symptoms varied considerably. Intraosseous lymphomas were frequently associated with paresthaesia or numbness. The most common roentgenological finding was a radiolucency with diffuse demarcation.

CONCLUSIONS

The clinical presentation, symptomatology and roentgenological appearance of intraoral lymphomas varied. Diagnostic delay was usually associated with a lymphoma initially misdiagnosed as a lesion of dental aetiology or a reactive lesion. Inadequate healing after tooth extraction or symptoms of numbness or pain without obvious dental origin should merit further clinical and roentgenological examination. Biopsy is indicated when there is the slightest doubt of the true nature of mucosal lesion.

Evidence that PKCα inhibition in Dalton's Lymphoma cells augments cell cycle arrest and mitochondrial-dependent apoptosis

Protein kinase Cα (PKCα), belonging to ser/thr protein kinase, perform various biological functions. Overexpression of PKCα has been observed in multiple human malignancies including lymphoma. However, the molecular pathogenesis and involvement of PKCα in Non-Hodgkin lymphoma (NHL) are not clearly understood. Hence, deciphering the role of PKCα in NHL management may provide a better therapeutic option. In the present study, we used selective pharmacological inhibitors Gö6976 and Ro320432 that potentially inhibit PKCα-mediated signaling in DL cells, resulting in the inhibition of cell growth and mitochondrial-dependent apoptosis. PKCα inhibition by these inhibitors also displays cell cycle arrest at the G1 phase and causes growth retardation of DL cells. Our results extended the mechanism of PKCα in NHL, and provided potential implications for its therapy.

Lymphomas of the head-and-neck region

Background

Lymphomas of the head and neck are always a challenge for an ENT specialist whose goal is to make a quick diagnosis.

Aim

Accordingly, clinical and epidemiological analysis of head-and-neck lymphoma was performed to approximate diagnostic difficulties.

Materials and Methods

The diagnosed patients with head-and-neck lymphoma in our center were assessed in 2012-2019.

Results

The study group included 22 patients with head-and-neck lymphoma including 20 non-Hodgkin's lymphoma (NHL) and 2 Hodgkin's lymphoma (HL). NHL showed symptoms in the lymph nodes of the neck, tonsils, parotid gland, and the orbit. HL showed exclusive manifestation in the lymph nodes of the neck and tonsils.

Conclusions

Uncharacteristic symptoms of lymphoma are always a challenge for the ENT specialist whose task is to quickly determine the diagnosis that forms the basis for further treatment. Interview, physical examination, imaging, and laboratory tests can only be suggestions for the diagnosis or exclusion of lymphoma; always, the decisive test is histopathological examination of the lymph node or a fragment of the affected organ.

Lymphoma in an extraction socket

Non-Hodgkin's lymphoma (NHL) is a lymphoproliferative malignancy that can involve both lymph node and lymphoid organs as well as extranodal organs and tissues. The aim of presenting this case of NHL is to highlight the suspicion of its occurrence in the region of unhealed extraction sockets and the significance of its awareness. NHL can be presented in various forms; therefore, a thorough knowledge regarding this malignancy is essential for arriving at the earliest possible diagnosis and therapy for the patient.

Clinical presentation and characteristics of lymphoma in the head and neck region

Background

The study analyses clinical characteristics of histologically defined head and neck (H&N) lymphoma to raise the awareness of ENT specialists to the leading symptoms.

Method

From 2003 to 2011, all patients with histologically defined H&N lymphoma from our clinic were evaluated.

Results

This study identified 221 patients with H&N lymphoma comprising 193 non-Hodgkin lymphomas (NHL) and 28 Hodgkin lymphomas (HL). Among NHL there were 77 indolent (iNHL), 110 aggressive (aNHL), six highly aggressive NHL and further 28 HL. Patients with highly aggressive NHL and HL were significantly younger (p < 0.0001). Corresponding to the leading symptoms, we found nodal and extranodal involvement. NHL demonstrated manifestation in neck lymph nodes, tonsils, major salivary glands, sinonasal-system and hypopharynx/larynx. HL showed exclusive manifestation in lymph nodes of the neck and the tonsils (p < 0.0001). The mean time from first symptoms to diagnosis ranged from 1.5 ± 0.7 months in highly aggressive lymphoma to 7.5 ± 11.5 months in iNHL.

Conclusions

The variable clinical presentation of lymphoma is a challenge for the ENT specialist. Fast diagnosis is crucial for rapid treatment, especially in highly aggressive NHL like the Burkitt-lymphoma and HL. A standardized medical history, clinical examination and imaging evaluations paired with patient’s signs, symptoms and demographic knowledge might indicate lymphoma. Biopsies in the H&N region should always be immediately performed in suspicious findings.

Waldeyer ring lymphoma: a case series

We encountered a patient with a tongue base lymphoma that we initially diagnosed as a lingual tonsil in view of its benign appearance. We established the correct diagnosis of Waldeyer ring lymphoma by histology. This case led us to conduct a study of all cases of Waldeyer ring lymphoma that had been treated at our center during a 10-year period. We retrospectively examined our case records and found 35 such cases. From this group, we excluded 5 cases because of incomplete data. Thus our final study group was made up of 30 patients-14 males and 16 females, aged 14 to 76 years (mean: 51.6; median 54). The primary presenting signs and symptoms were dysphagia (n = 17 [57%]), a neck mass (n = 7 [23%]), nasal symptoms (n = 5 [17%]), and pain (n = 1 [3%]). Only 4 patients (13%) had B symptoms. A total of 20 patients (67%) presented with tonsillar involvement, 8 (27%) with nasopharyngeal involvement, 1 (3%) with tongue base lymphoma, and 1 with anterior tongue involvement. Most patients (77%) presented at an early stage. Histologically, 25 patients (83%) had high-grade diffuse large B-cell lymphoma, 4 (13%) had T-cell lymphoblastic lymphoma, and 1 (3%) had follicular lymphoma. Twenty-one patients (70%) were treated with chemotherapy, 4 (13%) received adjuvant chemotherapy with either radiotherapy or surgery, 3 (10%) resorted to other forms of treatment (primarily traditional remedies), and 2 (7%) declined treatment altogether. There were 14 patients (47%) alive at the end of the study period.

Oral manifestations of lymphoma: a systematic review

Lymphoma is a malignant disease with two forms: Hodgkin's lymphoma (HL) and non-Hodgkin's lymphoma (NHL). Non-Hodgkin's lymphoma is diagnosed in extranodal sites in 40% of cases, and the head and neck region is the second most affected, with an incidence of 11-33%, while HL has a very low incidence in extranodal sites (1-4%). The aim of this study was to identify the oral manifestations of lymphoma through a systematic literature review, which we conducted using the PubMed, Lilacs, Embase, and Cochrane Library databases. We found 1456 articles, from which we selected 73. Among the intraoral findings, the most frequent were ulcerations, pain, swelling, and tooth mobility, while the extraoral findings included facial asymmetry and cervical, submandibular, and submental lymphadenopathy. Among the few studies reporting imaging findings, the most cited lesions included hypodense lesions with diffuse boundaries, bone resorptions, and tooth displacements. The publications reviewed highlight gaps in the areas of early detection, diagnosis, and proper treatment.

A rare spindle-cell variant of non-Hodgkin's lymphoma of the mandible

A 64-year-old male farmer presented with a rapidly progressive swelling of the left mandible since 6 months. The swelling was firm to hard, diffuse, nontender, obliterating the vestibule with paresthesia of lower lip. The cone beam computed tomography imaging revealed an ill-defined, moth-eaten radiolucency with destruction of the buccal and lingual cortical plates. The rapid growth and aggressive behavior of the lesion coupled with guidance from the patient's previous reports from the incisional biopsy and fine needle aspiration cytology warranted a mandibular resection. Microscopic examination showed an encapsulated lesion situated in the connective tissue containing a mixture of proliferating spindle-shaped cells arranged in fascicles and round cells infiltrating into the connective tissue stroma and bone. The neoplastic cells exhibited atypical features such as pleomorphism, hyperchromatism and increased mitotic figures with noncleaved nuclei. A working diagnosis of a spindle-cell sarcoma was arrived at with various differentials provided such as fibrosarcoma, rhabdomyosarcoma, leiomyosarcoma, malignant peripheral nerve sheath tumor, Langerhans cell histiocytosis and lymphoma and stating the need for immunohistochemistry to subtype the tumor. The neoplastic cells were negative for Van Gieson's stain and Masson's trichrome. Immunohistochemical analysis performed using desmin, smooth muscle actin, S-100 and CD1a in a bid to determine the phenotype of the tumor and rule out the previously stated differentials were all negative for the lesion. Lymphoid markers such as leukocyte common antigen and CD20 (cluster differentiation marker for B-cells) showed positivity in spindle-shaped cells as well as round cells indicating the tumor to be a lymphoproliferative lesion of B-cell type. A final diagnosis of “spindle-cell variant of non-Hodgkin's lymphoma” was rendered based on the immunohistochemical profile.

Oral signs of acute leukemia for early detection

PURPOSE

Systemic disease can manifest oral signs at an early phase, which may be crucial for the diagnosis and timing of treatment. This report describes two patients who presented with gingival enlargement as an early sign of acute leukemia.

METHODS

Two patients presented with oral symptoms including severe gingival enlargement. The progress of their symptoms was associated with underlying systemic disease.

RESULTS

The patients were transferred to the Department of Hematology and diagnosed with acute myelomonocytic leukemia. They received appropriate treatment and survived.

CONCLUSIONS

Gingival enlargement can be caused by underlying systemic diseases. Accurate diagnosis and timely referral are important for preventing a fatal situation. It must be emphasized that some oral signs and symptoms may be closely correlated with systemic diseases.

Malignant lymphoma of the oral cavity and the maxillofacial region: overall survival prognostic factors

Objective: To identify the overall survival and prognostic factors of malignant lymphoma of the oral cavity and the maxillofacial region. Study Design: Clinical records data were obtained in order to determine overall survival at 2 and 5 years, the individual survival percentage of each possible prognostic factor with the actuarial technique, and the survival regarding the possible prognostic factors with the actuarial technique and the Log-rank and Cox’s regression tests. Results: Of 151 subjects, an overall survival was 60% at 2 years, and 45% at 5 years. The multivariate analysis demonstrated statistically significant differences for clinical stage (p=0.002), extranodal involvement (p=0.030), presence of human immunodeficiency virus (p=0.032), and presence of Epstein-Barr virus (p=0.010). Conclusion: The advanced clinical stage and the larger number of involved extranodular sites are related to a lower overall survival, as well as, the presence of previous infections such as the human immunodeficiency and the Epstein-Barr virus.

Key words:Lymphoma, oral cavity, survival.

Primary B-cell MALT lymphoma of the palate: A case report and distinction from benign lymphoid hyperplasia (pseudolymphoma)

Diagnosis of palatal swellings is a challenge. Benign and malignant tumors may be misinterpreted as lesions of inflammatory origin. We present a case of B-cell non-Hodgkin lymphoma on the palate of a 40-year-old male. A number of factors can make the diagnosis of oral lymphoma difficult. Many lymphomas are extranodal, there is usually a prominent superimposed nonspecific inflammatory response and thus they mimic benign lymphoid hyperplasia. It is important for the pathologist to be familiar with features that distinguish benign from malignant lymphoid proliferations.

Marginal zone lymphoma of mucosa-associated lymphoid tissue with prominent plasma cell differentiation affecting the palatine tonsil: histopathological and immunohistochemical analysis

Non-Hodgkin lymphomas (NHLs) of the oral cavity and oropharynx constitute 13% of all primary extranodal NHLs. Marginal zone B-cell lymphoma of the mucosa-associated lymphoid tissue (MALT lymphoma) in the palatine tonsil is rare, corresponding to 6% of the NHLs of the Waldeyer ring. Some cases of MALT lymphoma can present prominent plasma cell differentiation, and less commonly, monoclonal gammopathy. The differential diagnosis of these cases from other NHLs with plasmacytic differentiation or plasma cell neoplasms is very difficult. In this article, we describe a rare case of MALT lymphoma in a 34-year-old man presenting as a swelling of the palatine tonsil. The tumor mass was diagnosed as MALT lymphoma with prominent plasma cell differentiation. Systemic evaluation was noncontributory. This is the first report of MALT lymphoma showing extensive plasmacytic differentiation of the palatine tonsil, and reinforces a possible relationship between extramedullary plasmacytoma and MALT lymphoma.

Mantle cell lymphoma of the oral cavity with multiple foci: a case report and review of the literature

Non-Hodgkin lymphomas (NHLs) are often present outside the lymph nodes. Although primary extranodal NHLs form a substantial part of all NHLs, reports on oral primary extra nodal NHLs are rare. Mantle cell lymphoma (MCL) is a rare B-cell neoplasm that has only recently been defined as a distinct entity. MCL of the oral cavity is an uncommon diagnosis. Most oral MCLs occur in an elderly male population and have a possible predilection for the palate. The microscopic diagnosis can be challenging, given its similar appearance to other small cell lymphomas, requiring a comprehensive immunohistochemical panel for the accurate diagnosis. Like MCL occurring in other sites in the body, the prognosis and outcome of oral MCL appears to be poor.

Trends and distribution of oral and pharyngeal lymphoma in Israel

OBJECTIVES

To describe the distribution and trends of oral and pharyngeal lymphoma cases in Israel.

METHODS

Incidence rates were derived from the Israel National Cancer Registry and included all registered data from 1970 to 2006. Oral lymphoma included the tongue, mouth, salivary glands, tonsils, and pharynx. Morphological description was according to WHO classification of lymphoid neoplasms.

RESULTS

A total of 670 cases were diagnosed, mean age 59.5 years, half were over 65 years old. Tonsils were the most prevalent site of involvement (36.0%), followed by the pharyngeal region and salivary glands. Over the years, the prevalence of lymphoma in salivary glands increased by 49%, whereas in tonsils lymphoma decreased by 28.6%. The overall 5-year survival rate was 57% with best rates among young people.

CONCLUSION

The correlation of survival, type of lymphoma and age, was similar to extra-oral lymphoma. A trend of increased cases in the parotid region, dissimilar to other oral sites, raises a question of possible external factors or an increase in autoimmune diseases. Head and neck clinicians should be aware of different sites, types, and prognoses for the different age groups.

T-cell lymphoma of the oral cavity: a case report

Lymphomas are defined as heterogeneous malignancies of the lymphatic system characterized by a proliferation of lymphoid cells or their precursors. Malignant lymphoma of the oral cavity has been described previously although reports on the occurrence of intraoral extranodal T-cell lymphomas are scarce. Oral lesions may appear as a painless enlargement, erythematous, often with surface ulceration secondary to trauma. This is a report of a rare case in which a specific subtype of T-cell lymphoma appeared in the oral cavity.

Oral lesions and lymphoproliferative disorders

Lymphoproliferative disorders are heterogeneous malignancy characterized by the expansion of a lymphoid clone more or less differentiated. At the level of the oral cavity, the lymphoproliferative disorder can occur in various ways, most commonly as lymphoid lesions with extranodal externalization, but sometimes, oral lesions may represent a localization of a disease spread. With regard to the primary localizations of lymphoproliferative disorders, a careful examination of the head and neck, oral, and oropharyngeal area is necessary in order to identify suspicious lesions, and their early detection results in a better prognosis for the patient. Numerous complications have been described and frequently found at oral level, due to pathology or different therapeutic strategies. These complications require precise diagnosis and measures to oral health care. In all this, oral pathologists, as well as dental practitioners, have a central role in the treatment and long-term monitoring of these patients.

Primary non-Hodgkin's lymphoma of the mandible

Primary non-Hodgkins's lymphoma is a very uncommon lesion, accounting for 0.6% in jaws. As the lesions frequently resemble other disease such as chronic osteomyelitis, odontogenic or any secondary neoplasms, further evaluation and histopathologic examination allow early identification for appropriate treatment. The purpose of this case report is to describe a rare case of non-Hodgkin's lymphoma of the mandible, explore the diagnosis and workup based on immunohistochemistry.