Primary extranodal non-Hodgkin lymphoma (NHL) is a rare manifestation of lymphoid malignancies and typically arises in tissues outside the lymph nodes and can involve various organs and anatomical sites presenting unique challenges in diagnosis and treatment. Multifocal primary extranodal NHL, characterized by simultaneous involvement of multiple extranodal sites, presents a diagnostic and therapeutic challenge due to its uncommon presentation and varied clinical manifestations. Despite advances in diagnostic modalities and treatment strategies for NHL, multifocal involvement poses unique clinical dilemmas requiring a multidisciplinary approach for accurate diagnosis and optimal therapeutic intervention. In this case report, we describe a rare case of multifocal primary extranodal NHL in a 29-year-old female, highlighting the complexities associated with its diagnosis and management. Through this case presentation, we aim to underscore the importance of recognizing and addressing the intricacies of multifocal primary extranodal NHL to enhance clinical outcomes and improve patient care. It also highlights the diagnostic complexity and clinical challenges associated with multifocal primary extranodal NHL. A multidisciplinary approach involving haematologists, oncologists, radiologists, and pathologists is crucial for the accurate diagnosis and optimal management of such cases. Additionally, further research is warranted to better understand the underlying pathogenesis and improve treatment strategies for this rare presentation of NHL.

In a clinical context, oral lymphomas are very uncommon and frequently challenging to identify. Mucosa-associated lymphoid tissue (MALT) lymphomas are a diverse category of lymphomas that were formerly believed to be formed from B-cells located in the marginal zone, which surrounds B-cell follicles and the surrounding lymphoepithelium. Extranodal organs like the stomach, thyroid, and large salivary glands are where they most frequently appear. As a result, they are accurately identified as extranodal marginal zone B-cell lymphomas (ENMZL). This report presents a case of a 53-year-old female with lower lip swelling, which was diagnosed as a case of marginal low-grade B-cell non-Hodgkin\'s lymphoma after clinical, histopathological, and immunological examinations. Non-Hodgkin\'s lymphoma diagnosis can be aided by pathological examination and biopsy performed early in the lesion\'s development. The dentist has a key role to play in the early diagnosis process.

Anaplastic large-cell lymphoma (ALCL) is a subtype of T-cell lymphoma. This disease mainly affects lymph nodes, although extranodal sites may also be involved. Lymphoma in the pancreas is a rare clinical entity whether it manifests as primary or extranodal involvement. We discuss an unusual case of a 29-year-old male patient who presented with epigastric pain and a right neck mass. The patient\'s symptoms, physical examination, and laboratory tests prompted further investigation using imaging modalities such as CT, MRI, and endoscopic ultrasound, which revealed the presence of soft tissue masses in the right supraclavicular region and an ill-defined lesion within the pancreatic head. These findings eventually led to the identification of secondary extranodal pancreatic lymphoma. Fine needle biopsy (FNB) established an ultimate diagnosis of anaplastic lymphoma kinase (ALK)-positive ALCL.

Diffuse large B-cell lymphoma (DLBCL) commonly affects the gastrointestinal (GI) tract, although primary DLBCL rarely occurs in the colon. Primary colorectal lymphoma is a surprisingly rare diagnosis, accounting for a minute percentage of GI lymphomas and colorectal malignancies. We present an interesting case of an immunocompromised young adult female who was diagnosed with DLBCL confined to a cecum polyp after she underwent a colonoscopy for a GI bleed. The lymphoma presented endoscopically as a semi-sessile polyp in the cecum that was successfully removed. The patient was treated with appropriate therapy of rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP).

OBJECTIVE: MEITL is a very rare and highly aggressive peripheral T cell lymphoma with poor prognosis and for which there is no standard treatment. Treatment options for patients patients with relapsed/refractory disease are scarce and the choice of an appropriate rescue still represents an unmet need.
METHODS: Here, we report the case of a 65-year-old woman affected by MEITL, progressing after initial treatment with an anthracycline-based chemotherapy and surgery, who received single-agent PEG-asparaginase salvage therapy at our institution.
RESULTS: PEG-asparaginase single-agent rescue proved to be rapidly effective in controlling the disease and its associated paraneoplastic features. Nevertheless, toxicity was high and the patient died due to a treatment-related complication.
CONCLUSIONS: The case we described brings new evidences on the effectiveness of PEG-asparaginase therapy in MEITL patients. Whether PEG-asparaginase should be included in the treatment course of MEITL patients could be the subject of future studies.

Follicular lymphoma is the second most common type of B-cell non-Hodgkin lymphoma. It is known as one of the indolent lymphomas. Although some cases presenting with abdominal masses with or without symptoms have been reported, generally, primary extranodal follicular lymphoma is uncommon. Moreover, small bowel obstruction (SBO) as an initial presentation is extremely uncommon. We encountered a unique case of mesenteric follicular lymphoma that presented with SBO as the initial clinical presentation. A 61-year-old male presented with a three-day history of abdominal pain and recurrent vomiting. Abdominopelvic computed tomography revealed air-fluid levels in multiple small bowel loops, with a transition point associated with a mass-like mesenteric abnormality. The small bowel was resected, and a wedge resection was performed to relieve the obstruction and make a diagnosis. Histopathology and immunohistochemical staining confirmed the diagnosis of follicular B-cell lymphoma. Mesenteric lymphomas are less likely to present with SBO as the initial clinical presentation due to their extraluminal location. According to the literature review on the types of lymphomas that cause SBO, follicular lymphoma accounted for only 4.9% of lymphoma cases with SBO due to its indolent course.

Extranodal involvement is more prevalent in diffuse large B-cell lymphoma (DLBCL) compared to other non-Hodgkin lymphoma subtypes, with up to 40% of patients with early-stage disease having at least one extranodal site. Virtually any tissue can be involved, but primary skeletal muscle and bone DLBCL is exceedingly rare. Here we report a case of DLBCL of the humerus and proximal limb musculature in a Vietnam War combat veteran with significant Agent Orange exposure and untreated hepatitis C infection. The patient presented with 1,25-dihydroxyvitamin D3-mediated malignant hypercalcemia and massive soft tissue infiltration. He had an excellent treatment response to chemotherapy and involved field radiation therapy. Also, we discuss hepatitis C and Agent Orange in the context of the pathogenesis and management of DLBCL.

Enteropathy-associated T-cell lymphoma (EATL) is a tumor of intraepithelial T-lymphocytes arising in the small intestine. Based on the genetic profile, immunohistochemistry, and histology, EATL is divided into two subtypes. EATL type I occurs in individuals with celiac disease (CD) while EATL type II is a sporadic form that occurs in individuals without CD. Intensive chemotherapy and surgery are the mainstay treatment. However, despite the currently available treatment options, the five-year survival rate is only 9%. EATL presents as abdominal pain, nausea, or slow gastrointestinal bleeding. Severe bleeding leading to hemodynamic instability is rarely known in EATL. Therefore, we present a unique case of EATL who presented with acute and severe gastrointestinal bleeding with no prior history of CD.

Primary diffuse large B-cell lymphoma of the tongue base (BOT) is an extremely rare entity with only a few cases described in the English literature to date. The incidence of BOT non-Hodgkin\'s lymphoma (NHL) increases with age, most commonly after the sixth decade of life with no observed gender differences. Our patient presented with a six-month history of right neck swelling, one-month history of dysphagia, a change in voice, and ultimately acute airway distress, which led to a tracheostomy. We report an extremely rare case of a diffuse large B-cell lymphoma presenting with airway distress. The patient was treated using rituximab-cyclophosphamide-doxorubicin-vincristine-prednisone (R-CHOP) chemotherapy, a five-day steroid course, and one intrathecal methotrexate. The patient recovered completely and is alive at the time of this writing. NHLs occur more commonly in patients like ours with a prior history of congenital immunodeficiency and celiac disease, exposure to radiation, acquired immune deficiency syndrome, rheumatoid arthritis, or Sjögren\'s syndrome. Most reported cases of BOT NHLs may cause dysphagia, pharyngeal foreign body sensation, or progressive dyspnea. This case highlights that although NHL of the tongue is a very rare entity, it should not be overlooked and should always be in the differential diagnosis among various benign and malignant tumors and may cause rapid respiratory deterioration.

Gene expression profiling (GEP) separated diffuse large B-cell lymphoma (DLBCL) in two different entities, i.e. activated B cell-like (ABC) and germinal center B cell-like (GCB) lymphomas with ABC lymphomas demonstrating a less favorable outcome. NF-kB pathway activating mutations in MYD88, CD79A/B and CARD11 are predominantly found in ABC type lymphomas. Targeted therapies affecting NF-kB pathways have shown therapeutic potential in this subtype. Immunohistochemistry algorithms have been developed as a tool for distinguishing these entities in routine clinical diagnostics. To test whether this immunohistochemistry classifier would detect the biological differences between the entities 147 DLBCLs were subtyped into ABC and GCB using the Visco-Young algorithm. Mutation analysis demonstrated mutations in MYD88 or CD79 A/B in 21% (10/47) of non-GCB type but only in 3% (1/31) of GCB lymphomas (p = 0.012) in nodal lymphomas. In primary extra nodal lymphomas, however, 17.5% (4/23) of GCB type and 37.5% (15/40) of non-GCB lymphomas carried mutations in MYD88 and CD79 A/B. While the Visco-Young algorithm was sufficient to detect biological differences (i.e. mutation patterns) in nodal DLBCL it did not distinguish GCB and non-GCB type lymphomas of primary extranodal sites. Here, the morphological sites of the lymphomas seem to be more important for their molecular pattern than their immunohistochemical status.