Lymphomas are the malignant neoplasms of lymphocytes and their precursor cells. Their diagnosis can sometimes be difficult due to their similarity to various other entities. A 10-year-old female reported swelling on the right side of the upper jaw for a month which was associated with mild continuous pain. On examination, a mild diffused swelling was noted on the right middle third of the face region which was firm in consistency and slightly tender. Intraorally, a firm tender swelling was noted on the right side of the hard palate. A proximal caries was noted with 55. A provisional diagnosis of dentoalveolar abscess with 55 was made. A panoramic radiograph showed loss of lamina dura concerning 11, 12, 53, 14, and 55, and loss of floor of the maxillary sinus. Cone-beam computed tomography and computed tomography-paranasal sinus revealed an ill-defined, hypodense osteolytic lesion with irregular borders extending from the 11 to 15 tooth region. Radiographic evaluation was suggestive of an infectious or neoplastic lesion. An incisional biopsy was performed and sent for histopathological and immunohistochemical analysis. A diagnosis of T-cell lymphoblastic lymphoma was made based on the features seen. The patient was sent for chemotherapy and radiotherapy. The reduction in the size of the lesion was noted on follow-up. Lymphoblastic lymphoma is a neoplasm of lymphocytes that is rarely seen in the oral cavity. Early diagnosis and prompt treatment are necessary to prevent further complications.

BACKGROUND: The gastrointestinal tract is a well-known extranodal site of lymphoma. B-cell lymphoma is the most common type, while T-cell lymphoma is uncommon. Primary gastrointestinal lymphoma mainly occurs in the stomach and small intestine, and the colon is less frequently involved, especially in females.
METHODS: A 45-year-old woman was admitted to our hospital for physical examination. Gastroenteroscopy revealed a visible pedunculated polyp in the transverse colon, for which endoscopic submucosal dissection (ESD) was performed. Pathology suggested highly active proliferation of T lymphocytes with atypical hyperplasia.
CONCLUSIONS: A middle-aged female patient was found to have colonic T-cell lymphoma by endoscopy. The lesion was successfully removed by ESD, and the surgical margin was negative. It is essential to raise awareness of colonic T-cell lymphoma and choose the appropriate treatment.

The patient presented to the clinic with painful muscle swelling in the right lower extremity, which improved with immunosuppressive therapy. Initially, the condition was diagnosed as polymyositis but recurred soon after. After imaging and biopsy, the final diagnosis was primary skeletal muscle peripheral T-cell lymphoma, not otherwise specified (PSM-PTCL, NOS). In this report, we discuss the challenges in diagnosing and treating this aggressive malignancy and review the literature on PSM-PTCL, NOS. Key Points • To date, there are few reports of PSM-PTCL, NOS, and our case is the tenth. • It is crucial to consider PSM-PTCL, NOS, when presenting with localized muscle edema and unexplained pain. • Histopathological examination is likely the most effective method for diagnosing this rare disease.

Hemophagocytic lymphohistiocytosis (HLH) is a rare and life-threatening condition that results from excessive immune activation and inflammation. This condition may be triggered by various factors, including infections, malignancies, or autoimmune diseases. Here, we report the case of a 39-year-old male who developed HLH secondary to T-cell lymphoma and had a history of multiple autoimmune disorders. Our patient presented with shortness of breath and weakness which led to an admission for methicillin-resistant Staphylococcus aureus bacteremia. His hospital course deteriorated rapidly due to his worsening condition. He was confirmed to have HLH based on the HLH-2004 criteria with the presence of fever, splenomegaly, hypertriglyceridemia, hypofibrinogenemia, low natural killer cell function, high ferritin, and soluble interleukin 2 receptor levels. Peripheral blood smear and bone marrow biopsy showed atypical lymphocytes consistent with a T-cell lymphoma, but no hemophagocytosis. He was treated with dexamethasone and etoposide. Despite treatment, the patient passed away. This case aims to contribute further to the understanding of secondary HLH in the setting of T-cell lymphoma. It also illuminates how vital early recognition and treatment are in patients with secondary HLH.

Monomorphic epitheliotropic intestinal T-cell lymphoma (MEITL) is a rare and aggressive T-cell neoplasm associated with poor survival. We report a case of MEITL that presented as an ulcerated mass in the jejunum with perforation. Microscopic examination showed that the neoplasm involved the full thickness of the intestinal wall, extended into the mesentery, and was composed of monomorphic, small to medium-size cells. Immunohistochemical analysis showed that the neoplastic cells were positive for T-cell receptor (TCR) delta, CD3, CD7, CD8 (small subset), BCL-2 and TIA-1, and negative for TCR beta, CD4, CD5, CD10, CD20, CD30, CD34, CD56, CD57, CD99, ALK, cyclin D1, granzyme B, MUM1/IRF4, and TdT. The Ki-67 proliferation index was approximately 50 %. In situ hybridization for Epstein-Barr virus-encoded RNA (EBER ISH) was negative. Next-generation sequencing (NGS) analysis showed mutations involving SETD2 and STAT5B. The patient was treated with aggressive chemotherapy and consolidative autologous stem cell transplant and had clinical remission, but relapsed after about one year. Retreatment led to another one-year interval of clinical remission, but at last follow up the patient has relapsed disease involving the ileum and colon. We also discuss the differential diagnosis of MEITL.

Primary or secondary non-Hodgkin lymphomas (NHLs) involving the female gynecologic tract are rare. T-cell subtypes are further rare and portend a worse prognosis. We present a case of a 23-year-old female presenting with a cervical mass accompanied by constitutional symptoms and abnormal vaginal bleeding. Immunohistochemistry studies revealed the presence of disseminated T-cell non-Hodgkin lymphoma that was anaplastic lymphoma kinase (ALK)-positive. The patient demonstrated a complete response to systemic chemotherapy initially and again after the relapse of the disease one year after diagnosis. To our knowledge, this is the first case of an ALK-positive T-cell lymphoma with secondary involvement of the uterus and cervix; all previously published cases of this histologic subtype in the gynecologic tract describe primary disease of the vagina. This case emphasizes the importance of immunohistochemistry studies inclusive of T-cell and B-cell markers when evaluating biopsies from cervical tumors to render the appropriate diagnosis and guide systemic therapy.

T-cell lymphoma is an extremely rare form of malignancy in the female genital tract. Most of the reported cases of lymphoma are B-cell lymphomas. A few cases of primary T-cell lymphomas involving the vagina or the vulva have been reported. We are reporting the first case of anaplastic large cell lymphoma (ALCL) presenting as a uterine cervical mass. The patient is a 24-year-old female who presented to the emergency room with a history of menorrhagia, night sweats and 40-pound weight loss. The diagnosis of ALCL was confirmed through immunohistochemical studies with strong CD30 and ALK expression. Fluorescent hybridization showed a rearrangement of the anaplastic lymphoma kinase (ALK) gene. Since ALCL may have a variable expression of T-cell antigens, the diagnosis may easily be missed when CD45 and/or CD3 is negative, and screening epithelial stains for carcinoma (e.g., p63 and EMA) are positive. CD30 must be performed to raise the consideration of ALCL when reniform nuclei are observed.

BACKGROUND: Primary central nervous system lymphoma (PCNSL) is a non-Hodgkin lymphoma that originates in the central nervous system (CNS) and is exclusively limited to the CNS. Although most PCNSLs are diffuse large B-cell lymphomas, primary CNS T-cell lymphomas (PCNSTLs) are rare. PCNSTLs typically demonstrate some degree of enhancement on contrast-enhanced magnetic resonance imaging (MRI). To the best of our knowledge, non-enhancing PCNSTL has not been reported previously.
METHODS: A 69-year-old male presented to the neurology department with complaints of mild cognitive impairment and gradual onset of left lower leg weakness over a span of two weeks. Initial MRI showed asymmetric T2-hyperintense lesions within the brain. No enhancement was observed on the contrast-enhanced T1 image. The initial diagnosis was neuro-Behçet\'s disease. Despite high-dose steroid therapy, no alterations in the lesions were identified on initial MRI. The patient\'s symptoms deteriorated further. An MRI performed one month after the initial scan revealed an increased lesion extent. Subsequently, brain biopsy confirmed the diagnosis of PCNSTL. The patient underwent definitive combined chemo-radiotherapy. However, the patient developed bacteremia and died of septic shock approximately three months after diagnosis.
CONCLUSIONS: The absence of enhancement in the lesion did not rule out PCNSTL. A biopsy approach is advisable for pathological confirmation.

Monomorphic epitheliotropic T-cell lymphoma (MEITL) of gastrointestinal tract is an aggressive T-cell lymphoma that can rarely involve the brain. We present detailed descriptions of clinical and autopsy neuropathological findings of a rare case of an elderly woman who had surgery and chemotherapy for MEITL of the small intestine. Following her surgery, she progressively exhibited neurologic decline towards the end of her treatment. The patient eventually succumbed to her illness and was found to have MEITL with intracranial involvement on autopsy. Brain autopsy was performed and examination of tissues with hematoxylin-eosin staining under optical microscopy with 100 X magnification. Immunostaining for CD3, CD4, CD5, CD7, CD8, CD56, CD20, beta-amyloid, c-Myc, TCR-beta, TCR-delta, and EBER-ish was conducted on the formalin-fixed paraffin-embedded (FFPE) brain tissues. A neuropathological exam revealed multifocal friable necrotic and hemorrhagic areas in the supratentorial region. Histologically, monotonous small to medium-sized atypical lymphocytes infiltrated the brain parenchyma, prominently around the vessels. The immunophenotype of the atypical lymphocytes was positive for CD-3, CD-7, and CD-56 and negative for CD-5, CD-4, CD-8, CD-20, and c-Myc. EBER-ish was negative. The histology and immunophenotype confirmed the MEITL brain involvement. Neurologic decline and cognitive changes in patients with known MEITL can be the first clue of brain involvement upon which prompt evaluation is warranted.

Neurolymphomatosis occurs due to the infiltration of a nerve by malignant cells. Cranial neurolymphomatosis is a rare disease process associated with non-solid tumors (i.e., lymphoma, leukemia, etc.). Cranial neurolymphomatosis presents with single or multifocal neuropathy. Primary cranial neurolymphomatosis is defined as the initial presenting symptom leading to a new diagnosis of cancer. Secondary cranial neurolymphomatosis is defined as cancer progression with spread to a cranial nerve. While cranial neurolymphomatosis is a recognized cause of cranial nerve neuropathies, a myriad of other malignancies can also lead to similar clinical manifestations. This case series elucidates not only the classical presentations associated with cranial neurolymphomatosis but also introduces other oncologic entities that may compromise cranial nerve functions. A descriptive case series is presented on six patients with malignancy-related cranial neuropathy who came to a tertiary-care center from 2018 to 2022. 5/6 (83.3%) of patients presented with primary cranial neuropathy. Diffuse large B-cell lymphoma was the most prevalent malignancy observed in 3/6 (50.0%) cases. Other malignancies observed include non-Hodgkin lymphoma, monoclonal B-cell lymphocytosis, and peripheral T-cell lymphoma. The most affected cranial nerve was the trigeminal nerve in 4/6 (66.6%) individuals. Multiple cranial neuropathies were seen in 2/6 (33.3%) of patients. The most common neuroradiographic finding was a lesion to Meckel\'s cave. Other cranial nerves affected include the optic, facial, and vestibulocochlear nerves. Diagnostic modalities utilized included magnetic resonance imaging and 18F-fluoro-2-D-glucose positron emission tomography-computerized tomography. Cerebrospinal fluid analysis for flow cytometry may also have diagnostic value in patients with increased disease burden. Treatment was guided according to individual malignancy and 2/6 (33.3%) patients achieved complete remission, 2/6 (33.3%) died within 1 year, and 1/6 (16.6%) were referred to hospice. Cranial neuropathy may be the first symptom of a neoplastic process; thus, prompt recognition and treatment may improve morbidity and mortality.