Occasional Cells Research Articles

Rare Case of Cutaneous Rosai Dorfman Disease Involving the Nail

Abstract Introduction/Objective Rosia-Dorfman Disease (RDD) is a rare benign non-Langerhans cell histiocytic disorder of unknown etiology with heterogeneous clinical features. RDD was first described by Destombes in 1965 under the term “adenitis with lipid excess.” However, it is named after Rosai and Dorfman, who characterized the further histopathological features of the disease in 1969. The characteristic presentation of RDD is lymphadenopathy, and extra nodal sites include bone, upper respiratory tract, central nervous system, retroperitoneum, and skin. The management of RDD depends on the site of involvement and the presence or absence of the symptoms. Multifocal and refractory diseases require systemic treatment. Surgical resection can be considered in symptomatic and resect- able diseases. Methods/Case Report A 16-year-old Asian female with no significant past medical history presented with a painful verrucous lesion on the left 5th finger for one year with bleeding and purulent discharge. Excision was performed, and histologically, there was extensive infiltration of large histocytes in the dermis with occasional lymphocytes and plasma cells. The histiocytes were engulfing the intact inflammatory cells, exhibiting the emperipolesis phenomenon. Immunohistochemically, S100 and CD68 were positive in the large histiocytes, and leukocyte common antigen (LCA) was positive in the background lymphocytes. Based on histology and immunohistochemistry, RDD diagnosis was rendered. Results (if a Case Study enter NA) N/A Conclusion RDD is a rare condition that poses challenges in diagnosis and management. The key diagnostic factors are histological features and immunohistochemistry to exclude other pathological disorders. Treatment should be tailored according to the needs of each patient and as required to optimize the outcome. We recommend an appropriate diagnosis of this entity in a timely manner to prevent any further long-term complications.

Characterisation of the tumour microenvironment in primary and recurrent glioblastomas.

Glioblastoma patients have a dismal prognosis, due to inevitable tumour recurrence and respond poorly to immunotherapy. Tumour-associated microglia/macrophages (TAMs) dominate the glioblastoma tumour microenvironment and have been implicated in tumour progression and immune evasion. Early recurrent glioblastomas contain focal reactive regions with occasional fibrosis, chronic inflammation, TAMs and tumour cells. Surgical specimens from these tumours are rare and provide crucial insights into glioblastoma recurrence biology. This study aimed to characterise TAM- and lymphocyte phenotypes in primary vs early- and late-recurrent glioblastomas. Patient-matched primary and recurrent glioblastomas were compared between patients with early recurrences (n = 11, recurrence ≤6months) and late recurrences (n = 12, recurrence after 12-19 months). Double-immunofluorescence stains combining Iba1 with HLA-DR, CD14, CD68, CD74, CD86, CD163, CD204 and CD206 along with stains for CD20, CD3, CD8 and FOXP3 were quantified with software-based classifiers. Reactive regions in early recurrent tumours contained more TAMs (31.4% vs 21.7%, P = 0.01), which showed increased expression of CD86 (59.4% vs 38.4%, P = 0.04), CD204 (48.5% vs 28.4%, P = 0.03), CD206 (25.5% vs 14.4%, P = 0.04) and increased staining intensity for CD163 (86.4 vs 57.7 arbitrary units, P = 0.02), compared to late recurring tumours. Reactive regions contained more B-lymphocytes compared to patient-matched primary tumours (0.71% vs 0.40%, P = 0.04). Fractions of total, cytotoxic and regulatory T-lymphocytes did not differ. Early recurrent glioblastomas showed enrichment for TAMs, expressing both pro- and anti-inflammatory markers and B-lymphocytes. This may indicate a time-dependent response to immunotherapy explained by time-dependent alterations in the immune-microenvironment in recurrent glioblastomas.

Granulomatous cheilitis: a rare case report

Granulomatous cheilitis is a rare granulomatous disorder characterized by a recurrent firm swelling of one or both lips. This is called the cheilitis granulomatosa of Miescher (CGM) when it occurs in isolation. It is called Melkersson-Rosenthal syndrome (MRS) if the classical triad of recurrent or persistent orofacial edema, plicated or fissured tongue (lingua plicata), and relapsing peripheral facial nerve paralysis is present. A 40-year-old female patient came to the Dermatology Department with persistent painless swelling of both lips and perioral area for the last one year. On histopathological examination there was a nodular tuberculoid granulomatous inflammation in patchy pattern present throughout the submucosa. The granuloma consists of lymphocytes, histiocytes and occasional plasma cells. AFB stain and PAS stain were negative. Diagnosis of granulomatous cheilitis was made and patient was put on tab clofazimine and intralesional corticosteroids. The case is being reported due to its rarity and the role of dermatopathologist to make a diagnosis.

Plexiform fibrohistiocytic tumor: A series of 10 case studies.

We sought to investigate the clinicopathologic features and differential diagnosis of plexiform fibrohistiocytic tumor (PFHT) and its pathogenesis. Ten cases of PFHT were collected from Xi Jing Hospital, Fourth Military Medical University, from September 2008 to December 2022 for clinical data as well as microscopic and immunohistochemical observation. CCND1 gene amplification and break were assayed by fluorescence in situ hybridization (FISH). We report 10 cases of PFHT according to histologic classification. Seven cases were of histiocytoid type, and 3 had mucous degeneration in the nodules. One case was of fibroblastic type, which was mainly composed of fibroblast-like cells. Two cases were of mixed type. Immunohistochemically, the osteoclast-like multinucleated giant cells, histiocyte-like cells, and occasional spindle cells in the adjacent fascicles were reactive for CD68 (10/10), CD163 (5/8), CD10 (8/8), cyclin D1 (8/8), CDK4 (5/8), β-catenin (4/6), MITF (2/6), and PGP9.5 (4/5). Vimentin (9/9) was strongly positive in tumor cells and peripheral fibroblast-like cells. The positive index of Ki-67 was 5% to 40%, with an average of 20%. The FISH analysis showed neither amplification nor break of the CCND1 gene. All cases underwent surgical resection, and patients were followed up for 9 months to 11 years. Only 2 cases recurred. Plexiform fibrohistiocytic tumor is a low-grade malignant soft tissue neoplasm. The diagnosis mainly depends on histopathologic and immunohistochemical markers. Cyclin D1 and CD10 expression has diagnostic value for the diagnosis and differential diagnosis of PFHT combined with its plexiform morphology. The overexpression of cyclin D1 suggests an involvement of cell cycle regulatory genes in the pathogenesis of PFHT.

Extensive intraocular melanoma with secondary glaucoma in a 15-month-old Thoroughbred filly.

A 15-month-old, grey, Thoroughbred filly presented for investigation of a 6-week history of corneal oedema and blepharospasm on the right eye (OD). The filly was otherwise healthy. Following ophthalmic examination, glaucoma on the OD was diagnosed. A space occupying mass within the anterior chamber was documented on transpalpebral ultrasonographic examination. This mass obliterated most of the anterior intraocular structures on the peripheral nasal side (corneal endothelium and drainage angle), leading to secondary glaucoma. After systemic and topical treatment addressing secondary glaucoma, the corneal oedema reduced. The mass was visualised as an irregularly rounded brown structure associated with the iris on the peripheral nasal side of the anterior chamber. Given the filly's signalment, location and appearance of the mass, a tentative diagnosis of intraocular melanoma was made and enucleation was performed. Histopathological evaluation of the globe revealed solid sheets of heavily pigmented melanocytic cells, disrupting the normal ciliary body architecture and extending into the iris and subretinal. The cells were pleomorphic, polyhedral to round with occasional spindle-shaped cells, and contained moderate to large amounts of granular black-brown pigment (melanin). The iridal component expanded into the anterior chamber, with cells directly opposed to Descemet's membrane, with loss of the endothelium and expanding and occluding the filtration angle in this area. The lesion infiltrated locally into the edge of the sclera, but did not extend through the sclera, though occasional perivascular clusters of melanophages were observed within the scleral stroma adjacent to the optic nerve. Diagnosis of a uveal melanocytic neoplasm was confirmed, with characteristics similar to only one reported case . This is a unique case of a rapidly growing, invasive, uveal melanoma in a young horse. Intraocular melanoma should be considered as a differential diagnoses for glaucoma in grey horses, regardless of the age and absence of melanocytic skin lesions.

Plasma Cell Infiltrate in Liver Allograft Biopsy: Clinical and Histological Implications

Introduction: The relevance of plasma cells in the allograft liver is of utmost importance and objective assessment of these infiltrates and correlation with other ancillary findings needs to be evaluated. Materials and Methods: Three hundred and sixty-eight graft liver biopsies received in the department from 2012 to 2022 and 115 allograft liver biopsies with histopathological diagnosis of rejection were selected. Based on plasma cells percentage in the portal tracts, the biopsies were divided into three groups: Group 1 showing not more than an occasional plasma cell, Group 2 showing <10% plasma cells, and Group 3 showing >10% plasma cells. Rejection activity index (RAI), portal/lobular inflammation, interface activity, subendothelial inflammation (portal and central vein), duct damage/loss, presence of cholestasis, apoptosis, perivenulitis, necrosis, rosette along with serial liver function tests (LFTs), and patient status at 1 year of follow-up were recorded and compared between the groups. Results: Plasma cell infiltrates were observed in 52.6% of the specimens, with the mean percentage of plasma cells in the infiltrates being 4.9. Increased plasma cell infiltrates were associated with higher RAI scores, marked duct damage, marked portal and central vein endotheliitis, marked portal inflammation, and presence of interface activity. Higher levels of transaminitis were recorded at the time of biopsy, but no significant association was observed in the fall of serial LFTs over a 2-week period with the presence of plasma cells. Conclusion: Identifying plasma cell infiltrates in liver allografts can serve as a clue toward increased severity of rejection in liver allograft biopsies. Further studies with emphasis on correlation with the clinical outcome and response to treatment are needed to validate its utility as an objective tool.

Disseminated histiocytic sarcoma in a degu (Octodon degus).

A 7-year-and-8-month-old, male degu (Octodon degus) with anorexia, depression, and labored breathing was found to have a thoracic effusion and enlargement of the right testis on radiographic examination. Despite treatment, the animal died. At necropsy, hepatomegaly, splenomegaly, and multifocal nodules on the intestinal serosa and mesentery were observed. Histologically, the foci were densely cellular invasive neoplasms composed of sheets of round to polygonal cells, with occasional multinucleated giant cells. Immunohistochemically, the neoplastic cells were immunopositive for ionized calcium-binding adapter molecule 1, human leukocyte antigen-DR, and CD204. These findings were consistent with disseminated histiocytic sarcoma.

Enhancing bioactivity and mechanical performances of hydroxyapatite-calcium sulfate bone cements for bone repair: in vivo histological evaluation in rabbit femurs.

This study deals with synthesizing hydroxyapatite-calcium sulfate bone cements or HAP-xCaS for bone repair. The effect of CaS on the setting time, injectability, washout resistance, phase evolution, water absorption, and physical, microstructural, and mechanical properties, as well as in vitro apatite-forming ability test and pH behavior of the HAP were investigated. Implantation of bone cement in rabbit femur and in vivo histological analysis were also analyzed. Initial and final setting times decrease with increasing CaS, which would be helpful for clinical procedures. All compositions have mixed phases of HAP, CaS, brushite, and gypsum. The prepared bone cement exhibited a dense structure and increased linear shrinkage with increasing CaS content. Adding more CaS inhibited grain growth and improved the mechanical properties, including compressive strength (σ c), bending strength (σ f), and Young's modulus (E). SEM micrographs displayed that the x = 0.7 or HAP-0.7CaS bone cement produced the highest ability to induce in vitro apatite formation, indicating its biocompatibility. In vivo histological analysis for the HAP-0.7CaS bone cement demonstrated that more new bone formed around defects and bone cement particles. Osteoblasts were found peripherally at the bone trabeculae, and occasional osteoblast-like cells were observed at the granules after 4-8 weeks of implantation. The obtained results indicated that the HAP-0.7CaS bone cement has the potential to exhibit good bioactivity, injectability, and good mechanical properties for bone repair applications.

Testicular granular cell tumor of two rabbits: case reports

Granular cell tumor was described in the testis of two rabbits. Testis from each rabbit was surgically removed and submitted for histopathological diagnosis. Both testes were about 2.0 cm in diameter, firm, and tan. Microscopically, testicular mass consisted of compact sheets of round to polygonal and occasional spindle-shaped cells. The neoplastic cells contain a large amount of eosinophilic granular material in the cytoplasm. The cytoplasmic eosinophilic granules were positive for periodic acid Schiff stain. Immunohistochemically, the neoplastic cells were immunoreactive to Melan-A and vimentin. Based on these results, the testicular mass was diagnosed as a granular cell tumor.

Angioimmunoblastic T-Cell Lymphoma with Concurrent EBV Viremia: A Challenging Case

Abstract Introduction/Objective Angioimmunoblastic T-cell lymphoma (AITL) represents only 1-2% of all non-Hodgkin lymphomas but is one of the most common non-cutaneous T-cell lymphomas. Although typically associated with latent Epstein Barr Virus (EBV) infection, recent studies have demonstrated the presence and prognostic impact of EBV viremia at the time of diagnosis. Here, we present a case of AITL in which the diagnosis was complicated by EBV viremia. Methods/Case Report A 41-year-old male presented to our hospital with generalized abdominal pain, diffuse lymphadenopathy, hepatomegaly, ascites, and diffuse body wall edema. A recent retroperitoneal lymph node biopsy reportedly demonstrated features suggesting an infectious process, and EBV PCR revealed a viral load of 141,050 copies/mL. A left axillary lymph node was excised, which demonstrated vascular proliferation and diffuse architectural effacement by a polymorphous infiltrate including variably sized lymphocytes with moderate to abundant clear cytoplasm, and occasional admixed neutrophils, plasma cells, and eosinophils. Immunohistochemical staining demonstrated an atypical CD4-positive, CD7-negative T-cell population in a vaguely nodular distribution, expressing Bcl-6, PD-1, ICOS, and CXCL13 without definite CD10 expression. CD21 immunostaining demonstrated markedly expanded follicular dendritic cell meshworks in a distribution similar to the atypical T-cell population. No B-cell or cytotoxic T-cell proliferation was seen, and in situ hybridization for EBV-encoded RNA (EBER ISH) demonstrated only scattered EBV- positive cells. Taken together, these findings supported a diagnosis of AITL over an atypical reaction to EBV infection. Next-generation sequencing demonstrated mutations in TET2, IDH2, and RHOA, further confirming the diagnosis. Results (if a Case Study enter NA) NA Conclusion AITL manifests with a diverse range of clinical symptoms and pathological features and may mimic infection. Additionally, acute EBV infection is well-known to mimic various lymphomas and has rarely been reported to mimic AITL. We present this case to raise awareness of the concurrent presentation of AITL with EBV viremia and to highlight features that may be helpful in distinguishing between the two.

Large orbital masses due to longstanding hydrogel retinal explants.

To describe the features of orbital masses occurring as a late complication of hydrogel retinal explants. Retrospective review of patients presenting with orbital masses at decades after retinal surgery. Two patients with huge orbital masses are described, their presenting 25 and 28 years after retinal detachment repair with expansile hydrogel explants. In one case, the preoperative diagnosis was pleomorphic adenoma, and the other-with extreme distortion of the globe-was considered to be lymphoma or chronic inflammation arising around prior retinal explants. At orbitotomy, the masses were found to be grossly expanded hydrogel explants that were removed piecemeal from their fibrous capsules. Histopathology showed very mild inflammation with occasional multinucleate giant cells and patchy capsular calcification, and an eosinophilic amorphous material staining strongly with Alcian-blue. Surgery was uncomplicated and both orbits healed with marked functional improvement. Expansile hydrogel retinal explants were largely used in the 1980s and can present, often decades after the retinal surgery, with impaired orbital functions due to large parabulbar masses. The hydrophilic material appears to expand very slowly over decades, leading to gross distortion of neighbouring structures and a tumour-like mass.

FRI168 LH-hCG Receptor Is Expressed In All Three Zones Of Normal Adrenal Glands But Not In Aldosterone-Producing Micronodules

Abstract Disclosure: S.A. Reda: None. A. Kirschenbaum: None. S. Yao: None. L. Milgram: None. J. Rege: None. A.C. Levine: None. Embryologically, the adrenals and gonads develop from the urogenital ridge with differential migration and differentiation. Post-natally, pituitary adrenocorticotropic hormone (ACTH) stimulates adrenal cortical cell growth and steroidogenesis, whereas pituitary luteinizing hormone (LH) regulates gonadal cell growth and steroidogenesis. However, there are multiple reports of gonadal tumorigenesis driven by high ACTH (in congenital adrenal hyperplasia) and adrenal cortical tumorigenesis driven by high LH/human chorionic gonadotropin (hCG) levels (adrenal tumors in pregnant and postmenopausal females). We studied the immunohistochemical expression of LH/hCG receptor (LH/hCG-R) in normal adrenal glands from 12 kidney donors (four male and eight female, two of which were <50 years of age and six were >50 years of age). Some of these specimens also contained aldosterone producing micronodules (APMs). Staining was performed for Synaptophysin, aldosterone synthase (CYP11B2), LH/hCG-R, WNT/β-Catenin, and DLK-1. In normal adrenal tissue, we first used synaptophysin stain to identify the nerves in the adrenal cortex as well as the adrenal medulla (M). CYP11B2 staining demonstrated immunoreactivity in a linear pattern throughout the Zona Glomerulosa (ZG) in five of the 12 samples. Faint expression of LH/hCG-R was detected in all twelve samples throughout the three layers of the adrenal cortex: the ZG, Zona Fasciculata (ZF) and Zona Reticularis (ZR). However, there were occasional cells in both the ZR and ZF that stained intensely for LH/hCG-R expression. LH/hCG-R immunoreactivity was also noted in the progenitor-rich subcapsular (SC) region. WNT β-Catenin, a transcription factor involved in the proliferation of adrenal cortical cells, stained most heavily in the SC/ZG region, possibly representing adrenal cortical progenitor cells. DLK-1, an adrenal cortical progenitor cell marker, was also expressed in the subcapsular zone. In adrenal tissues containing APMs, CYP11B2 immunostaining revealed areas of CYP11B2 positive cells that dip into the ZF, with no preserved linear staining for CYP11B2 in the ZG. LH/hCG-R stained most densely in the SC and ZG regions, with little to no immunoreactivity in the APMs. WNT β-Catenin likewise stained the SC and ZG regions with no expression in the APMs. Our findings suggests that LH/hCG-R is expressed sporadically in normal adrenal cortical tissue, but densely at times in all three zones of the adrenal cortex and the subcapsular area where the putative adult progenitor cells reside. The LH/hCG-R does not appear to be expressed throughout the entirety of APMs. Presentation: Friday, June 16, 2023

P27 A case of unilateral scleritis and biopsy proven retinal vasculitis in an elderly woman with rheumatoid arthritis and previous retinal detachment surgery with silicone oil band

P27 A case of unilateral scleritis and biopsy proven retinal vasculitis in an elderly woman with rheumatoid arthritis and previous retinal detachment surgery with silicone oil band

Uterine Neurotrophic Tyrosine Receptor Kinase Rearranged Spindle Cell Neoplasms: Three Cases of an Emerging Entity.

Uterine sarcomas are rare; most are either smooth muscle or endometrial stromal in origin. Recent molecular advances have identified several, genetically defined entities with specific morphologic, clinicopathological associations, and therapeutic options. We report 3 cases of uterine neurotrophic tyrosine receptor kinase ( NTRK )-rearranged spindle cell neoplasms," currently classified as "emerging entities" in the WHO Classification of Female Genital Tract Tumors, 2020, Fifth Edition. The affected patients were 32, 34, and 42 years of age. Two patients presented with vaginal bleeding; the third presented with a cervical mass found incidentally during laparoscopy for an ectopic gestation. All 3 tumors were polypoid masses that distorted the cervix. Microscopically, they comprised cellular, fascicular, and storiform, plump spindle cells, with occasional rounded cells, and frequent mitoses (4-48/10 high power fields) in a myxoid stroma. All 3 cases showed entrapment of benign cervical glands. Inflammatory cell infiltrates, including plasma cells, were noted in all 3 tumors. One case had tumor cell necrosis, osteoid-like material, and osteoclast-like giant cells and showed lymphovascular invasion. Immunohistochemically, our cases showed patchy S100 (2/3) and CD34 (3/3) positivity. CD10 was positive in 2/3 cases. 3/3 cases showed pan-tropomyosin receptor kinase positivity (cytoplasmic). The NTRK -translocations demonstrated were: NTRK1::TMP3, NTRK1::TPR, and NTRK3::SPECC1L . Two of the patients had extensive disease and underwent chemotherapy. Larotrectinib was approved for one patient who demonstrated a striking reduction in tumor volume upon initiation of this treatment.

Pentastatin, a matrikine of the Collagen IVa5, is a novel endogenous mediator of pulmonary endothelial dysfunction.

Deposition of basement membrane components, such as collagen IVα5, is associated with altered endothelial cell function in pulmonary hypertension. Collagen IVα5 harbors a functionally active fragment within its C-terminal non-collageneous (NC1) domain, called pentastatin, whose role in pulmonary endothelial cell behavior remains unknown. Here, we demonstrate that pentastatin serves as a mediator of pulmonary endothelial cell dysfunction, contributing to pulmonary hypertension. In vitro, treatment with pentastatin induced transcription of immediate early genes and pro-inflammatory cytokines and led to a functional loss of endothelial barrier integrity in pulmonary arterial endothelial cells. Mechanistically, pentastatin leads to β1-integrin subunit clustering and Rho/ROCK activation. Blockage of the β1-integrin subunit or the Rho/ROCK pathway partially attenuated the pentastatin-induced endothelial barrier disruption. While pentastatin reduced the viability of endothelial cells, smooth muscle cell proliferation was induced. These effects on the pulmonary vascular cells were recapitulated ex vivo in the isolated-perfused lung model, where treatment with pentastatin induced swelling of the endothelium accompanied by occasional endothelial cell apoptosis. This was reflected by increased vascular permeability and elevated pulmonary arterial pressure induced by pentastatin. This study identifies pentastatin as a mediator of endothelial cell dysfunction, which thus might contribute to the pathogenesis of pulmonary vascular disorders such as pulmonary hypertension.

Molecular assessment of specimens previously assigned to Cirrulicarpus (Kallymeniaceae, Rhodophyta) in Brazil, with the description of Meredithia dichotoma sp. nov.

ABSTRACT Molecular sequence analyses of specimens previously identified as Cirrulicarpus sp. in the southeastern Brazil (Espírito Santo coast), indicated that they are more closely related to the genus Meredithia than to the genus Cirrulicarpus. The new species Meredithia dichotoma is herein proposed to accommodate this uncommon and endemic taxon, morphologically characterized by an erect, narrow, strap-shaped thallus, up to 16 cm long, mostly dichotomously branched, with regular constrictions, densely to moderately filamentous medulla, with occasional ganglionic cells, and an expanded medullary region in the basal transverse sections, resembling a midrib in surface view. The species is also supported by the sequence divergence from its congeners: ≥4.3% and 2.2% in the COI-5P and rbcL markers, respectively. Meredithia dichotoma differs from other 11 species of the genus by its dimensions and general habit, never forming expanded blades. This is a new genus record for Brazil and the first species of Meredithia known to occur in the western South Atlantic, increasing the known diversity in the red algal family Kallymeniaceae.

Lysinuric protein intolerance presenting as pancytopenia and splenomegaly mimicking acute leukaemia: a case report

BackgroundLysinuric protein intolerance is a rare inherited metabolic disease due to autosomal recessive mutations of the SLC7A7 gene. The affected patients commonly present with protein-rich food intolerance, failure to thrive, hepatosplenomegaly, muscle hypotonia and lung involvement due to impaired intestinal absorption and excessive urinary excretion of dibasic amino acids. Presentation with splenomegaly and cytopenia without other features has not been reported. Here we report a Sri Lankan girl with lysinuric protein intolerance presenting with pancytopenia and splenomegaly mimicking acute leukaemia.Case presentationTwo years and six months old Sri Lankan girl presented with persistent pancytopenia following a viral illness. She was asymptomatic without vomiting, diarrhoea, abdominal pain or irritability. Physical examination revealed pallor and isolated firm splenomegaly of 2 cm. Growth parameters and other system examinations were normal. Full blood count revealed anaemia, leukopenia and thrombocytopenia. The blood picture showed a mixture of hypochromic microcytic and normochromic normocytic red cells with occasional pencil cells and macrocytes. Bone marrow examination was normal except for occasional megaloblasts; however, serum vitamin B12 and red blood cell folate were normal. The metabolic screen showed a high anion gap compensated metabolic acidosis, high lactate and ketosis. Genetic mutation analysis using whole exome sequencing revealed compound heterozygous variants of the SLC7A7 gene, confirming the diagnosis of lysinuric protein intolerance.ConclusionWe report a child with lysinuric protein intolerance presenting with pancytopenia and splenomegaly without other disease features. This case report adds to the heterogenic presentations of lysinuric protein intolerance, which is considered a multifaceted disease.

Unilateral Multiple Evanescent White Dot Syndrome-Like Reaction Following the CyberKnife Stereotactic Radiotherapy for Choroidal Malignant Melanoma.

A 58-year-old otherwise healthy man received a diagnosis of choroidal malignant melanoma (CMM) in June 2021 and underwent a single session of (21 Gy) CyberKnife stereotactic radiotherapy (SRT). Eleven months later, we noticed 3+ anterior chamber cells with occasional vitreous cells in the left eye. Though the tumor looked regressed, there were mild optic disc leakage, early hypofluorescent and late hyperfluorescent punctate lesions scattered 360 degrees, and late staining of the mass on fluorescein angiogram. The findings were compatible with a unilateral multiple evanescent white dot syndrome (MEWDS)-like reaction that was most likely related to CyberKnife SRT-induced tumor necrosis, and a dexamethasone implant was administered intravitreally into the left eye together with topical steroids. A second intravitreal injection of dexamethasone was given three months later due to remittance of the angiographic features. As there are only a few reports on CyberKnife SRT for the treatment of CMM, we wanted to share our interesting observation of a post-treatment MEWDS-like reaction likely related to tumor necrosis syndrome with the ophthalmic community.

Perivascular epithelioid cell tumor of pancreas on the background of chronic liver disease: a case report and review of literature

Perivascular epithelioid cell tumours, known as PEComas, of the pancreas are an extremely rare group of neoplasms. This heterogenous entity includes angiomyo­lipo­ma (AML), clear cell sugar tumour (CCST), lymphangioleio­myoma (LAM), and another group of lesions originating from the soft tissues and organs with similar histological and immunophenotype characteristics. To date, only 23 cases have been reported throughout the world with different clinical presentations. We report a 52-year-old lady who presented with a symptomatic mass in the body of the pancreas on the background of hepatitis B virus (HBV)-related chronic liver disease (CLD). She presented with abdominal pain of 2 months' duration. On initial computed tomography (CT) imaging, it revealed a homogenously enhancing lesion in the body of the pancreas. It was T2 isointense on magnetic resonance imaging (MRI), and there was no uptake present in the 68Ga DOTONAC scan. Endoscopic ultrasound with fine needle aspiration (FNA) showed paucicellular material with occasional dysplastic cells. On account of suspicion of a non-functional neuroendocrine tumour, she underwent a distal pancreatosplenectomy. Intra-operatively, the lesion was encapsulated and hard in consistency, and the rest of the pancreas was soft with an undilated MPD. She had a smooth postoperative recovery. Final histopathology revealed benign PEComa of the distal body and tail of the pancreas with HMB 45 and SMA positivity on IHC. Currently, she has been on regular follow up for the last 12 months. PEComas usually present as a histological surprise and are a diagnosis of exclusion. However, knowledge of this exceptionally rare tumour makes diagnosis at the pre-operative level more certain. Resection must be considered, as it leads to a good prognosis and survival.

Auricular and laryngeal chondritis in nursery and finishing pigs.

This work aimed to characterize the clinic-pathological presentation of an outbreak of auricular and laryngeal chondritis in pigs. Visits were made to pig farms, where the clinical history was obtained, and clinical and postmortem examinations were performed. In those farms, 3% to 4% of pigs presented otohematomas, which started in the nursery and extended to the finishing phase. Moreover, some finishing pigs presented with respiratory distress, initially characterized as inspiratory dyspnea, associated by an uncommon respiratory stridor and culminating in death. Grossly, nursery piglets had enlarged ears, and on the cut surface, the cartilage was fragmented and associated with blood clots. In the finishing phase, in addition to auricular lesions, the epiglottis and arytenoid cartilages were thickened and distorted, which partially occluded the lumen. Microscopically, the laryngeal and auricular cartilages were fragmented, displayed a loss of matrix basophilia, and were surrounded by lymphohistiocytic inflammatory infiltrate, with occasional multinucleated giant cells and fibrosis. The lesions exclusively affected elastic cartilages. The disease in finishing pigs led to increased mortality and was a differential diagnosis to respiratory challenges. It was not possible to determine the factor that triggered this condition; however, a nutritional association is suspected. To the authors' knowledge, this is the first report of primary auricular and laryngeal chondritis in pigs.