Diagnostic Histopathology最新文献

Primary cutaneous B-cell lymphomas (PCBCL) and lymphoid proliferations are a heterogenous group of entities arising primarily in the skin with a broad spectrum of clinical and histological characteristics. In general, the prognosis of these neoplasms is better than their systemic counterparts and this emphasizes the need for an accurate diagnosis for patients. Two main categories are recognized so far in PCBCL based on their clinical behaviour. Indolent PCBCL includes Primary cutaneous marginal zone lymphoma (PCMZL), Primary cutaneous follicle center lymphoma (PCFCL) and Epstein Barr virus-positive mucocutaneous ulcer (EBV + MCU). The more aggressive PCBCL are cutaneous diffuse large B-cell lymphoma, leg type (PCDLBCL, LT) and intravascular large B cell lymphoma. Since the publication of the updated WHO-EORTC classification in 2018, new consensus guidelines and classifications have been published in the field of cutaneous lymphomas incorporating new discoveries in their genetics alterations and immunophenotype. Here, we summarize the main clinical, histological and molecular characteristics of primary cutaneous B-cell lymphomas and reactive B-cell rich lymphoid proliferations, highlighting the most relevant findings published recently in the medical literature.

Rosai-Dorfman disease is an inflammatory non-neoplastic disease characterized by a histiocytic infiltrate in a polymorphous inflammatory background. It is typically presents in lymph nodes; cutaneous manifestation is uncommon. We present a case of cutaneous Rosai-Dorfman disease with classic cytomorphological and immunohistochemical features with a discussion around prognosis, follow-up and molecular testing.

Angioimmunoblastic T-cell lymphoma was reclassified a subtype of nodal T-follicular helper cell lymphoma (nTFHL-AI) in the 5^th Edition of the World Health Organization Classification of Haematolymphoid Tumours. It is now grouped with related entities upon recent discovery of a shared T-follicular helper (TFH) cell origin. Numerous studies attest to the many peculiar presentations that impede recognition of the disease. Surgical biopsy is often required to secure a diagnosis though is rarely the first-line intervention. Delayed or missed diagnosis has a high price. Advanced stage of disease at presentation is common and rates of relapse are high. There is an unmet need for earlier detection and improved outcomes. Here we present a case which showed some quintessential clinicopathologic features of nTFHL-AI, and an approach to discerning these is discussed.

This review discusses a group of distinctive extranodal lymphomas that characteristically arise in anatomic spaces, with emphasis on their pathologic features, and including some historical perspective. The anatomic spaces include normal structures that are normally low-volume potential spaces that may expand due to the presence of fluid, inflammation or cellular infiltrate, such as the pleural cavity, as well as abnormal spaces, including cysts and pseudocysts. These lymphomas include diffuse large B-cell lymphoma associated with chronic inflammation, fibrin-associated large B-cell lymphoma, primary effusion lymphoma, fluid overload-associated large B-cell lymphoma, and breast implant-associated anaplastic large cell lymphoma.

Our understanding of the molecular aberrations in lymphoma, has been revolutionized by large scale sequencing studies, which has identified genetic mutations, transcriptional states and epigenetic dysregulation that define key subtypes with distinct biological properties and outcomes. Herein we provide an introduction to these findings, with a focus on mature B and T cell neoplasms, and discuss their significance in this vast and immensely fast moving field.

Indolent lymphomas of the gastrointestinal (GI) tract represent a challenging diagnostic area. Around one third of extranodal non-Hodgkin lymphomas (NHL) involve the GI tract. This may be primary, including several relatively recently described entities such as duodenal-type follicular lymphoma and intestinal T-cell lymphoma of the GI tract, or secondary involvement by systemic lymphoma. As a significant proportion of lymphomas may initially present in the GI tract, associated with non-specific GI symptoms without strong clinical suspicion for haematological malignancy, it is crucial that general and gastrointestinal pathologists are familiar with these entities. The differential diagnosis for an indolent-appearing lymphoid infiltrate in the GI tract ranges from reactive or benign conditions such as nodular follicular hyperplasia or coeliac disease, to highly aggressive lymphomas such as monomorphic epitheliotropic T-cell lymphoma. The aim of this review is to discuss indolent B-, T- and NK-cell lymphomas of the GI tract including the classification of the more recently described entities, with an emphasis on morphological and immunohistochemical features that may help the pathologist differentiate these from benign or aggressive malignant mimics, having significant implications for management and prognosis.

Penile lymphoma is a rare entity. Patients are often elderly, and present with an ulcerated painless mass on the shaft of the penis, strongly mimicking the more common diagnoses of infection, trauma or squamous cell carcinoma. Examination, radiological investigation and ultimately biopsy of the lesion is essential in making the diagnosis and guiding treatment. Herein, we present a case of diffuse large B cell lymphoma in the penis of an elderly gentleman, and review the salient histopathology regarding this uncommon entity.

Non-cutaneous extranodal mature T- and natural killer (NK)-cell neoplasms represent a broad spectrum of neoplasms involving various extranodal sites, predominantly in the liver, spleen, bone marrow, gastrointestinal tract, and nasal cavity, ranging from indolent to highly aggressive diseases. Extranodal NK/T-cell lymphoma (ENKTL), aggressive NK-cell leukaemia (ANKL), and EBV-positive T-cell and NK-cell lymphoid proliferations and lymphomas of childhood, are strongly associated with Epstein-Barr virus (EBV). Overlapping clinical and histopathological features exist between entities, making differentiation challenging. A multidisciplinary approach is essential in establishing the correct diagnosis. Recent advances in genomics have provided new insights into the pathogenesis, aided in the diagnosis, prognostication, and identification of potential therapeutic targets. This article focuses on the clinicopathologic features of these entities, incorporating recent advances in genetic characterization, and highlighting features that assist in distinguishing these conditions from potential mimickers.