Primary lacrimal sac melanoma: a case report describing the novel use of fine needle aspiration cytology (FNAC) for diagnosis, together with literature review and immunotherapy treatment update.

Primary lacrimal sac melanoma (PLSM) is exceedingly rare and associated with high morbidity and mortality. Unfortunately, PLSM often presents insidiously resulting in delayed detection and poor prognosis. A 69-year-old Black man was suspected of having a lacrimal sac tumour following presentation with a left sided watery eye, bloody tears, and a lacrimal mass. Due to the patient's implantable pacemaker, defibrillator, and high anticoagulation, an ultrasound-guided FNAC was performed instead of incisional biopsy, revealing a PLSM. Diagnosis was confirmed following complete tumour resection with free flap reconstruction and neck dissection. Unfortunately, disease progression ensued despite further neck dissection and three cycles of both pembrolizumab and iplimumab. This is the first description of FNAC to accurately diagnose PLSM and highlights its use as an accurate, rapid, and minimally invasive technique that may allow an earlier screening diagnosis of lacrimal sac tumours. We also discuss the outcome of immunotherapy in recent similar cases.

Clinicopathological characterisation of myeloproliferative neoplasm-unclassifiable (MPN-U): a retrospective analysis from a large UK tertiary referral centre.

Myeloproliferative neoplasm-unclassifiable (MPN-U) presents an MPN-type phenotype that fails to meet diagnostic criteria for other MPN variants. Variability in the clinicopathological phenotypes presents many challenges. Amongst a registry cohort of 1512 patients with MPN, 82 with MPN-U were included, with a median (range) age of 49·7 (13-79) years. Albeit heterogeneous, common presentation features included raised lactate dehydrogenase, thrombocytosis and clustered/pleomorphic megakaryocytes on trephine biopsy. Thrombosis was common (21%), necessitating vigilance. The median event-free survival was 11·25 years (95% confidence interval 9·3-not reached), significantly shortened in cases with lower platelet counts (<500 × 109 /l) and a leucocytosis (≥12 × 109 /l) at presentation. Generation of potential MPN-U prognostic scores is required.

A Problem of Classification: 2 Cases of Epstein-Barr Virus + Primary Cutaneous Plasmacytoma Arising in Immunocompetent Elderly Patients.

ABSTRACT: Primary extramedullary plasmacytoma is rare monoclonal proliferation of plasma cells, which arise in various nonosseous anatomic locations without detectable underlying systemic disease. Historically, cutaneous infiltrates rich in mature neoplastic plasma cells have fallen into one of the following categories, plasmacytoma, lymphoplasmacytic lymphoma, and marginal zone lymphoma, which included immunocytoma. Since 2005, each of these was subsumed under the marginal zone lymphoma umbrella, largely on the basis of acknowledged diagnostic difficulties in some of these cases. We describe 2 cases in which the cutaneous infiltrates consisted of a pure population of light chain-restricted mature plasma cells in the absence of any other evidence for a marginal zone proliferation, or evidence of extracutaneous involvement, including a paraprotein. We propose that primary cutaneous plasmacytoma is the accurate diagnosis and is consistent with wider nomenclature. The unusual observation of widespread Epstein-Barr virus expression in both tumors is also discussed.

The clinical and pathological panoply of systemic mastocytosis.

Mastocytosis is a rare disease with varied presentation, myriad symptomatology and variable prognosis. Most patients present with cutaneous disease and mediator-related symptomatology with a small subset having systemic disease (systemic mastocytosis, SM). A subset of the latter develops synchronous or metachronous haematologic neoplasms (SM-AHN), most commonly chronic myelomonocytic leukaemia (CMML). Advanced systemic mastocytosis (ASM) is seen in a relatively small number of patients and is usually associated with organ dysfunction, and may present with hepatosplenomegaly, lymphadenopathy and ascites with progression to leukaemic transformation (mast cell leukaemia/acute myeloid leukaemia) occurring in a few patients. This paper discusses the clinical and pathologic features of the entire spectrum of SM in adults.

Diagnosis and subtyping of de novo and relapsed mediastinal lymphomas by endobronchial ultrasound needle aspiration.

RATIONALE: The current management of lymphoma requires accurate diagnosis and subtyping of de novo lymphoma and of relapsed or refractory lymphoma in known cases. The role of endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) in the clinical management of lymphomas is unclear. OBJECTIVES: To investigate the use of EBUS-TBNA in the diagnosis of de novo and relapsed mediastinal lymphomas. METHODS: A total of 2,256 consecutive patients who underwent EBUS-TBNA in a tertiary center between February 2008 and April 2013 were prospectively evaluated. The diagnostic accuracy and clinical use of EBUS-TBNA in 100 cases of de novo or suspected relapsed mediastinal lymphoma was investigated by comparing EBUS-TBNA diagnosis with the final diagnosis. MEASUREMENTS AND MAIN RESULTS: De novo mediastinal lymphoma was correctly diagnosed by EBUS-TBNA in 45 (88%) of 51 and relapsed lymphoma in 15 (100%) of 15 lymphoma cases. EBUS-TBNA accurately established a diagnosis other than lymphoma in 32 (97%) of 33 patients with suspected lymphoma relapse. Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of EBUS-TBNA in the diagnosis of mediastinal lymphoma were 89%, 97%, 98%, 83%, and 91%, respectively. Sensitivity of EBUS-TBNA in subtyping lymphomas into high-grade non-Hodgkin lymphoma, low-grade non-Hodgkin lymphoma, and Hodgkin lymphoma was 90%, 100%, and 79%, respectively. EBUS-TBNA diagnosis was adequate for clinical management in 84 (84%) of 100 cases. CONCLUSIONS: Multimodality evaluation of EBUS-TBNA can be successful in the diagnosis of de novo mediastinal lymphomas and is ideally suited in distinguishing lymphoma relapse from alternative pathologies; it is least sensitive in subtyping Hodgkin lymphoma.

Sarcoidosis following COVID infection: A case series.

Here we describe three cases of sarcoidosis which were diagnosed following COVID infection. Treating clinicians should consider post-COVID-19 sarcoidosis in their differential, as it represents a potentially treatable cause of persistent symptomatology.

A comprehensive characterisation of phaeochromocytoma and paraganglioma tumours through histone protein profiling, DNA methylation and transcriptomic analysis genome wide.

BACKGROUND: Phaeochromocytomas and paragangliomas (PPGLs) are rare neuroendocrine tumours. Pathogenic variants have been identified in more than 15 susceptibility genes; associated tumours are grouped into three Clusters, reinforced by their transcriptional profiles. Cluster 1A PPGLs have pathogenic variants affecting enzymes of the tricarboxylic acid cycle, including succinate dehydrogenase. Within inherited PPGLs, these are the most common. PPGL tumours are known to undergo epigenetic reprograming, and here, we report on global histone post-translational modifications and DNA methylation levels, alongside clinical phenotypes. RESULTS: Out of the 25 histone post-translational modifications examined, Cluster 1A PPGLs were distinguished from other tumours by a decrease in hyper-acetylated peptides and an increase in H3K4me2. DNA methylation was compared between tumours from individuals who developed metastatic disease versus those that did not. The majority of differentially methylated sites identified tended to be completely methylated or unmethylated in non-metastatic tumours, with low inter-sample variance. Metastatic tumours by contrast consistently had an intermediate DNA methylation state, including the ephrin receptor EPHA4 and its ligand EFNA3. Gene expression analyses performed to identify genes involved in metastatic tumour behaviour pin-pointed a number of genes previously described as mis-regulated in Cluster 1A tumours, as well as highlighting the tumour suppressor RGS22 and the pituitary tumour-transforming gene PTTG1. CONCLUSIONS: Combined transcriptomic and DNA methylation analyses revealed aberrant pathways, including ones that could be implicated in metastatic phenotypes and, for the first time, we report a decrease in hyper-acetylated histone marks in Cluster 1 PPGLs.

Update on diagnostic approaches and therapeutic strategies in systemic mastocytosis.

Systemic mastocytosis is a rare disease which is being better recognized and managed. While the vast majority of patients have indolent disease with variable symptom burden, a small proportion evolve or present with aggressive disease. This may be due to increases in mast cell burden (leukemic, associated with tumour masses) or more commonly due to the presence of an additional hematologic neoplasm (SM-AHN). These patients with advanced systemic mastocytosis have poor outcome; however, recent advances in diagnosis, molecular genetics and treatment have changed the prognostic landscape for this group of patients. In this review we address the most topical questions related to diagnostics, classification, new disease entities, treatment and multiparameter prognostic scoring systems.

Case report of a man with multiple paragangliomas and pathogenic germline variants in both NF1 and SDHD.

We report a novel case of multiple paragangliomas in a patient who was identified with pathogenic variants in both NF1 and SDHD genes. The proband is a man with known familial NF1 disease, diagnosed clinically in childhood. Multiple head and neck paragangliomas (HNPGL) were found during investigations for acute left sided neurological symptoms, in the region of his known plexiform neurofibroma. He was referred for genetic counselling. He underwent surgery to remove a left carotid body tumor (CBT). A pheochromocytoma and paraganglioma gene panel was tested. Blood and HNPGL tumor DNA were analyzed by whole exome sequencing. In addition to the NF1 truncating variant c.5107delA, p.(Ser1703AlafsTer7), the SDHD truncating pathogenic variant c.3G > A, p.(Met1?) was found. Tumor sequencing showed no LOH of SDHD or NF1, but monoallelic loss of 11p15 and 11q12.2-q12.3 was observed. Co-occurrence of pathogenic variants in multiple cancer susceptibility genes is rare but possible, identified by the increased use of panel testing. This is the first description of a patient presenting with NF1 and SDHD dual pathology, with HNPGL development due to SDHD. This case illustrates the central role of genetic sequencing in PPGLs and the strong genotype-phenotype correlations of different genes.

Allogeneic haematopoietic cell transplantation for myelofibrosis: proposed definitions and management strategies for graft failure, poor graft function and relapse: best practice recommendations of the EBMT Chronic Malignancies Working Party.

Allogeneic haematopoietic cell transplantation (allo-HCT) remains the only curative approach in myelofibrosis (MF). Despite advances over recent decades, relapse and non-relapse mortality rates remain significant. Relapse rates vary between 15 and 25% across retrospective studies and management strategies vary widely, ranging from palliation to adoptive immunotherapy and, in some cases, a second allo-HCT. Moreover, in allo-HCT, there is a higher incidence of poor graft function and graft failure due to splenomegaly and a hostile "pro-inflammatory" marrow niche. The Practice Harmonisation and Guidelines subcommittee of the Chronic Malignancies Working Party (CMWP) of EBMT convened an international panel consisting of transplant haematologists, histopathologists and molecular biologists to propose practical, clinically relevant definitions of graft failure, poor graft function and relapse as well as management strategies following allo-HCT. A systematic approach to molecular monitoring, histopathological assessment and chimerism testing is proposed. These proposed recommendations aim to increase the accuracy and uniformity of reporting and to thereby facilitate the development of more consistent approaches to these challenging issues. In addition, we propose management strategies for these complications.

Data set for reporting carcinoma of the thyroid: recommendations from the International Collaboration on Cancer Reporting.

Thyroid cancer therapy is increasingly tailored to patients' risk of recurrence and death, placing renewed importance on pathologic parameters. The International Collaboration on Cancer Reporting (ICCR), an organization promoting evidence-based, internationally agreed-upon standardized pathology data sets, is the ideal conduit for the development of a pathology reporting protocol aimed at improving the care of patients with thyroid carcinomas. An international expert panel reviewed each element of thyroid pathology reporting. Recommendations were made based on the most recent literature and expert opinion.The data set uses the most recent World Health Organization (WHO) classification for the purpose of a more clinically and prognostically relevant nomenclature. One example is the restriction of the term minimally invasive follicular carcinoma to tumors with capsular invasion only. It reinforces the already established criteria for blood vessel invasion adopted by the most recent WHO classification and Armed Forces Institute of Pathology fascicle. It emphasizes the importance of the extent of blood vessel invasion and extrathyroid extension to better stratify patients for appropriate therapy. It is the first data set that requires pathologists to use the more recently recognized prognostically powerful parameters of mitotic activity and tumor necrosis. It highlights the importance of assessing nodal disease volume in predicting the risk of recurrence.The ICCR thyroid data set provides the tools to generate a report that will guide patient treatment in a more rational manner aiming to prevent the undertreatment of threatening malignancies and spare patients with indolent tumors the morbidity of unnecessary therapy. We recommend its routine use internationally for reporting thyroid carcinoma histology.

Identifying HIV infection in diagnostic histopathology tissue samples--the role of HIV-1 p24 immunohistochemistry in identifying clinically unsuspected HIV infection: a 3-year analysis.

AIMS: Because of the clinical difficulty in identifying the early stages of human immunodeficiency virus (HIV) infection, the histopathologist often has to consider the diagnosis of HIV in tissue samples from patients with no previous suspicion of HIV infection. The aim was to investigate the practicality and utility of routine HIV-1 p24 immunohistochemistry on tissue samples received at a London histopathology laboratory. METHODS AND RESULTS: Over a 3-year period, HIV-1 p24 was evaluated immunohistochemically on 123 cases. Of these, 37 (30%) showed positive expression of p24 in lesional follicular dendritic cells (FDCs). Of these 37 cases, 11 were not clinically suspected to be HIV+ and had no prior serological evidence of HIV infection. These cases represented lymph node biopsies, tonsillar and nasopharyngeal biopsies and a parotid excision. In addition to expression on FDCs, in 22 cases (60%), p24 also highlighted mononuclear cells and macrophages. p24 was also useful in confirming the presence of HIV in lymphoid tissue in non-lymphoid organs such as the lung, anus, salivary gland and brain. Immunonegativity occurred in occasional known HIV+ cases, probably related to treatment or tissue processing. CONCLUSIONS: This study confirms the usefulness of this technique in detecting unsuspected HIV infection in lymphoid and non-lymphoid organs on histopathological material and should be part of routine evaluation of lymph nodes and lymphoid tissue in other organs if morphological or clinical features suggest HIV infection.

Primary Isolated Lymphoplasmacytic Lymphoma (LPL) of the Stomach: A Case Report.

BACKGROUND Lymphoplasmacytic lymphoma (LPL) is a mature B cell lymphoma that mostly involves the bone marrow, spleen, and lymph nodes. Involvement of extramedullary sites is very rare and has not been reported as the primary site before. CASE REPORT A 47-year-old man presented with reflux symptoms. Gastroscopy revealed a 1.5-cm gastroesophageal junction (GEJ) polyp and oesophageal ulcer. A biopsy was performed and histopathology showed active chronic inflammation with focal intestinal metaplasia and reactive epithelial changes. A CT abdomen showed eccentric thickening of the lower oesophagus and GEJ, with periesophageal, gastro-hepatic ligament, and coeliac lymph node (LN) enlargement. A laparoscopic biopsy showed no peritoneal disease. EUS showed a large ulcerated lesion in the GEJ and proximal stomach. Both were biopsied, showing squamous-columnar mucosa with edema and a population of plasma cells, small lymphocytes, and histiocytes. These expressed CD20, PAX5, CD79a, IgM, and were lambda light chain-restricted. Lymphocytes were negative for CD3, IgG, IgA, and IgD. The MIB-1 index was low. LPL was diagnosed. PET showed an increased uptake of the gastric cardia and GEJ. LNs were not metabolically active. Bone marrow was negative. Evaluation of MYD 88 mutational status failed. Serum immunofixation showed no paraprotein. These results led to a diagnosis of primary isolated LPL of the stomach. CONCLUSIONS Primary lymphoplasmacytic lymphoma may present as an isolated gastric tumor. This can be unassociated with a paraprotein in serum and increased lymphocyte/plasma cell populations within the bone marrow. Gastric LPL is rare. Physicians and pathologists need to be aware of this rare presentation.

Synchronous Microscopic Epstein-Barr Virus-Positive Diffuse Large B-Cell Lymphoma of the Adrenal and Lymphoplasmacytic Lymphoma: De Novo Disease or Transformation?

Lymphomas arising in the adrenal are rare, and to our knowledge, 2 cases of Epstein-Barr virus (EBV)-positive diffuse large B-cell lymphomas (DLBCL) in an adrenal pseudocyst have been reported. We report an incidental EBV-positive DLBCL arising in an adrenal pseudocyst in a 58-year-old man with a 7-year history of lymphoplasmacytic lymphoma (LPL). The DLBCL was present in the fibrinous exudate, while the LPL resided in the cyst wall. The patient underwent de-roofing of the same cyst 3 years previously; review of histology revealed foci of LPL in the cyst wall, but not of DLBCL. There have been reports of similar microscopic EBV-positive DLBCLs within enclosed cystic spaces. However, all these cases were incidental extranodal primary DLBCLs. Since residual LPL was present alongside DLBCL, with similar light chain restriction, we propose that this may represent transformation, rather than a de novo primary EBV-driven lymphoma.

CD10 in diffuse uterine leiomyomatosis: a case report along with a few comments on histogenesis.

Diffuse uterine leiomyomatosis (DUL) is a rare entity with an unknown etiopathogenesis. A 24 years old female presented with abdominal discomfort and menorrhagia. Clinical and ultrasonographic examination revealed an enlarged uterus. The hysterectomy specimen showed a symmetrically enlarged uterus with a bosselated external surface. The cut surface showed multiple nodules of varying sizes diffusely involving the myometrium. Microscopically, the nodules were leiomyomas of varying degrees of cellularity. Some of the leiomyomas showed an increased vascularity either in the form of congeries of blood vessels with a lobular arrangement or occasionally as foci of 2-3 vessels. The vessels were surrounded by whorls of spindle cells. On immunohistochemistry the leiomyomas expressed vimentin, smooth muscle actin (SMA), desmin and CD10: the cells whorling around the blood vessels expressed vimentin, SMA and focally desmin and were negative for CD10 and HMB-45. The aim of this paper is to document that CD10 is expressed in diffuse uterine leiomyomatosis and discuss the histogenesis of DUL.

18F-FDG PET Detection of a Medullary Thyroid Carcinoma in a Patient With SMZL.

Incidental thyroid FDG uptake is not rarely encountered on PET studies. In this case, we present an incidental thyroid focus of F-FDG uptake identified in a patient with splenic marginal zone lymphoma during the baseline and the response assessment PET/CT study that proved to be medullary thyroid carcinoma on subsequent histological examination.