Intracytoplasmic Granules Research Articles

Long-Term Survival in Canine Hepatosplenic T-Cell Lymphoma Treated with Toceranib Phosphate Following Splenectomy: A Case of Atypical Lymphoma

Toceranib phosphate (toceranib) is approved for canine mast cell tumor treatment. However, no long-term response to toceranib in canine HSTCL has been reported. Here, we describe a case of a 10-year-old castrated mixed-breed dog that presented with a 3-month history of weight loss, polydipsia, and polyuria. The clinicopathological and imaging abnormalities included icterus, biliary obstruction, and splenomegaly with multiple diffuse splenic hypoechoic nodules. On day 21, a cholecystectomy was performed to remove the obstruction, followed by a liver biopsy and splenectomy. Cytology of the spleen and liver showed many small lymphocytes with intracytoplasmic granules (sGLs). Splenic and hepatic infiltration of neoplastic CD3/granzyme B-positive small cells and lymphocytic cholecystitis with granzyme B-negative small cells were noted. T-cell receptor gene clonal rearrangements were observed in the liver tissues. The dog was diagnosed with a hepatosplenic T-cell lymphoma (HSTCL) of sGLs concurrent with lymphocytic cholecystitis. The icterus resolved after surgery, but there was progressive elevation of liver enzyme levels. Toceranib was administered from day 39, resulting in decreased liver enzyme levels, and the dog remained in good condition. The dog stayed in remission after toceranib administration and survived for 460 days. Toceranib should be considered an effective treatment option for canine HSTCL.

Malignant trichoepithelioma in the prepuce of a Pitbull breed dog

AbstractA 12‐year‐old, male Pitbull dog was referred for a voluminous mass in the prepuce. Physical examination revealed an oval mass, cauliflower‐shaped with an alopecic and ulcerated surface. Cytological examination revealed large amounts of neutrophil granulocytes and keratinised cells with several atypic features, such as anisokaryosis, anisocytosis, anisonucleosis, nuclear and cytoplasmic vacuolation, and mitoses. Histopathology of the surgically excised sample showed malignant epithelial cells arranged in trabeculae, islands and cords showing differentiation of all three segments of a hair follicle. In addition, there were foci of trichogenic differentiation with intracytoplasmic trichohyalin granules, and the presence of ghost cells in the epithelial islands. The macroscopic and histological features led to the diagnosis of a malignant trichoepithelioma according to the characteristics reported in the literature, except for the unusual localisation in the canine prepuce.

Establishment of a human ovarian clear cell carcinoma cell line mutant in PIK3CB but not PIK3CA

A human ovarian clear cell carcinoma cell line was established from a 46-year-old Japanese woman. That line, designated MTC-22, has proliferated continuously for over 6 months in conventional RPMI 1640 medium supplemented with 10% foetal bovine serum and has been passaged over 50 times. MTC-22 doubling-time is ~ 18 h, which is much shorter than most ovarian clear cell carcinoma lines reported to date. Morphologically, MTC-22 cells exhibit polygonal shapes and proliferate to form a monolayer in a jigsaw puzzle-like arrangement without contact inhibition. Ultrastructurally, cells exhibit numerous intracytoplasmic glycogen granules and well-developed mitochondria. G-band karyotype analysis indicated that cells have a complex karyotype close to tetraploid. We observed that the expression pattern of a series of ovarian carcinoma-related molecules in MTC-22 cells was identical to that seen in the patient’s tumour tissue. Notably, MTC-22 cells, and the patient’s carcinoma tissue, expressed low-sulphated keratan sulphate recognised by R-10G and 294-1B1 monoclonal antibodies, a hallmark of non-mucinous ovarian carcinoma, and particularly of clear cell ovarian carcinoma. Moreover, characteristic point mutations—one in ARID1A, which encodes the AT-rich interaction domain containing protein 1A, and the other in PIK3CB, which encodes the catalytic subunit of phosphoinositide 3-kinase—were seen in the patient’s tumour tissue and retained in MTC-22 cells. Collectively, these findings indicate that MTC-22 cells could serve as a valuable tool for investigating the pathophysiology of ovarian clear cell carcinoma, particularly that harbouring PIK3CB mutations, and for developing and validating new diagnostic and therapeutic approaches to this life-threatening malignancy.

ED-1 PITUITARY TUMORS IN 5TH WHO CLASSIFICATION 2022: WHAT DO YOU MEAN BY PITNET?

Abstract It has been well known that the terminology has been changed from pituitary adenoma(4th WHO) which means benign epithelial tumors to pituitary neuroendocrine tumor(5th WHO 2022). It is apparent that the anterior pituitary cells and derived tumors contain intracytoplasmic neurosecretory granules and belong to neuroendocrine cells, and naturally neuroendocrine tumors. The pancreatic and gastrointestinal neuroendocrine neoplasms(NEN) are composed of well differentiated neuroendocrine tumors(NET) and poorly differentiated neuroendocrine carcinoma(NEC). NETs are potentially malignant(metastatic) tumors and are further graded to G1,G2,G3 by proliferative activities(mitoses or Ki-67 indices) showing correlation with prognosis . PitNET which means pituitary NET is now classified by transcription factors(PIT1,TPIT,SF1) and some tumors show clinical symptoms,(hormone production) invasive growth and rarely metastasize indicating potential malignant behavior. From this broad biological spectrum of PitNET, ICD-O coding /3(primary malignancy) has been proposed(5th WHO CNS, Pediatrics and Endocrine volumes). It has been known that some histological patterns (Sparsely granulated somatotroph PitNET, Crooke cell PitNET and others) are related more aggressive growth of PitNETs, but metastatic behavior is very hard to predict histologically. So in WHO 4th edition, the term pituitary carcinoma was used only after confirming metastasis or remote spread. The metastatic tumors are now called metastatic PitNETs. Five tiered grading by proliferation and invasion has been also proposed(Trouillas). Now we need more updated genomic studies such as single cell RNA sequencing to clarify biologic behavior of the individual PitNET cells to further clarify the their nature. . In my talk, several points of interests regarding PitNETs will be discussed by demonstrating histology and biology of representative cases.

Seminal Vesicle Stromal Lipofuscinosis: A Rare Incidental Finding with Potential for Misdiagnosis.

We report a patient with isolated stromal lipofuscinosis of the seminal vesicle, a rare entity characterized by intracytoplasmic pigmented granules within stromal cells intimately surrounding seminal vesicle epithelium. Only 4 patients with this unusual phenomenon have been previously reported in the literature. Recognizing this incidental and presumably non-pathologic finding is important to prevent misclassification as a more concerning lesion.

Otosclerosis under the magnifying glass.

Otosclerosis is a bone condition affecting the stapes bone within the otic capsule, and its exact cause is still unknown. It is characterized by a lack of proper remodeling of newly formed vascular and woven bone, leading to the development of abnormal osteons and the formation of sclerotic bone. Bilateral otosclerosis is seen in 80% of patients and 60% of otosclerosis patients have a family history of the condition. The etiology of this disease is still unknown, there are lots of theories to explain it. The histopathological (HP) studies of otosclerosis showed that osteoblasts, osteoclasts, vascular proliferation, fibroblasts, and histiocytes were observed in the stapes footplate. The onset of the symptoms occurs by the early third decade of life, usually it doesn't start later. In otosclerosis, the energy exerted by sound at the level of the tympanic membrane is reduced in the inner ear due to the fixation and rigidity of the ossicular chain, leading to hearing loss, especially for low frequencies. The primary clinical symptom of otosclerosis is conductive hearing loss but it is important to note that sensorineural hearing loss and mixed hearing loss can also occur as secondary symptoms of the condition. Another symptom present in patients with otosclerosis is tinnitus. The paper carried out a retrospective study of 70 patients diagnosed with otosclerosis in the Department of Otorhinolaryngology of Emergency City Hospital, Timişoara, Romania, between January 2021 to December 2022. Tissue fragments were processed at Service of Pathology by standard Hematoxylin-Eosin staining. The HP diagnosis was completed using Masson's trichrome staining, Giemsa histochemical staining, and immunohistochemical (IHC) reactions with anti-cluster of differentiation (CD)20, anti-CD3, anti-CD4, anti-CD8, anti-CD34, and anti-CD31 antibodies. The microscopic examination showed a chronic diffuse inflammatory infiltrate that consisted predominantly of mature T-lymphocytes, immunohistochemically positive for CD3, CD4 and CD8. There were also present rare CD20-positive B-lymphocytes. Among the lymphocytes, relatively numerous mast cells were identified, highlighted histochemically by the Giemsa staining. They had numerous purple-violet intracytoplasmic granules. In the connective tissue support, a relatively rich vascular network was identified, consisting of hyperemic capillaries, highlighted immunohistochemically with anti-CD31 and anti-CD34 antibodies. Bone tissues trabeculae showed extensive areas of fibrosis. The collagen fibers were highlighted by Masson's trichrome staining, being stained in green, blue, or bluish green.

Primary Carcinoid Tumor of the Prostatic Urethra: Case Report and Review of the Literature

Abstract Introduction/Objective We report a case of a 72-year-old male with a past medical history of previously treated urothelial cell carcinoma without recurrence in over ten years. Methods/Case Report Surveillance cystoscopy revealed a small lesion involving the prostatic urethra. Microscopic examination of the prostatic urethra lesion revealed a proliferation of pseudoglandular structures within the lamina propria adjacent to an area of urothelial cystitis cystica et glandularis. The pseudoglandular structures contained primarily small bland nuclei with fine chromatin and featured frequent intracytoplasmic neuroendocrine granules. Scattered foci of enlarged hyperchromatic nuclei were present, but no necrosis or increased mitotic activity was identified. Immunohistochemistry revealed the lesional cells were diffusely positive for chromogranin and synaptophysin; while negative for GATA3 and NKX3.1. The histologic features and immunoprofile are characteristic of primary carcinoid tumor of the prostatic urethra, which uniquely shows a predominantly pseudoglandular architecture compared to carcinoid tumors of other sites and are often associated with reactive urothelial proliferations. Results (if a Case Study enter NA) NA. Conclusion Acknowledgement of this rare entity as a diagnostic mimicker is critical to ensure proper treatment and management of the patient.

S1935 A Unique Case of Small Duct Primary Sclerosing Cholangitis Leading to Recurrent Cholestatic Hepatitis

Introduction: Small Duct Primary Sclerosing Cholangitis (sdPSC) is the narrowing of intrahepatic bile ducts which often leads to cholestasis and cirrhosis. We present a patient diagnosed with sdPSC which is an uncommon form of PSC. Case Description/Methods: A 42-year-old male patient, with a history of hypertension and gunshot wound with bowel resection presented for abdominal pain associated with recurrent cholangitis. Previous history also included bouts of abdominal pain, jaundice and hyperbilirubinemia that occurred roughly three times a year. A liver biopsy was taken during admission and revealed mild portal inflammation and cholestasis, bridging fibrosis, and intracytoplasmic iron granules. One month later a colonoscopy showed patchy erythema with biopsies demonstrating mild acute proctitis. Given cholestatic pattern, + ANA 1:320, recurrent admissions with sepsis, and recent colonoscopy showing evidence of proctitis (biopsy proven), the patient was diagnosed with sdPSC with overlap of autoimmune cholangiopathy. The sdPSC was treated with a cadaveric liver transplant, and upon explant, the patient’s liver showed chronic obstructive cholangiopathy. His postoperative course was notable for persistently elevated bilirubin of which half was indirect. Upon ERCP, the liver showed a mild anastomotic stricture and tortuous duct which was treated with a stent. However, the stent was removed because of lack of frank stricture. The patient was started on a prednisone taper with tacrolimus. The patient is currently doing well post-transplant on low dose tacrolimus and mycophenolate. Discussion: Clinical presentation of sdPSC often consists of pruritis, jaundice, and acute cholangitis from cholestasis, and fatigue, liver failure and hepatosplenomegaly from liver cirrhosis. Notably, the patient presented with hepatomegaly, and jaundice. With this presentation, PSC, sdPSC, and benign recurrent intrahepatic cholestasis (BRIC) were all possible diagnoses. Unremarkable MRCP imaging highlighted the unlikeliness of PSC, and liver biopsy showed bridging fibrosis which excluded BRIC. Clinical diagnosis of sdPSC is difficult and a high degree of clinical suspicion is needed. The cause for Small Duct Primary Sclerosing Cholangitis is unknown, but there is an association with irritable bowel disease, presence of HLA-B8 and HLA-DR3 and autoimmune disease like hyper IgM.

Secretory carcinoma of the salivary gland, a rare entity: An international multi‐institutional study

BACKGROUNDSecretory carcinoma (SC) of the salivary gland is a rare entity with limited published literature on cytomorphology. The authors present the largest cohort to date of SC fine‐needle aspiration (FNA) cases.METHODSFNA cases of histologically confirmed SC were retrospectively retrieved from 12 academic institutions in the United States, Italy, Finland, and Brazil. The collated data included patient demographics, imaging findings, cytopathologic diagnoses according to the Milan System for Reporting Salivary Gland Cytopathology, cytomorphologic characteristics, and immunohistochemical/molecular profiles.RESULTSIn total, 40 SCs were identified (male‐to‐female ratio, 14:26) in patients with a mean age of 52 years (age range, 13‐80 years). Ultrasound imagining revealed a hypoechoic, ovoid, poorly defined, or lobulated mass. The most common primary site was the parotid gland (30 of 40 tumors). Regional lymph node metastasis (9 patients) and distant metastasis (4 patients; brain, liver, lungs, and mediastinum) were noted. Two patients died of disease. FNA smears were cellular and demonstrated mainly large, round cells with intracytoplasmic vacuoles or granules and round‐to‐oval nuclei with smooth nuclear contour, minimal irregularities, and prominent nucleoli arranged predominantly in clusters, papillary formations, and single cells. The background was variable and contained inflammatory cells, mucin, or proteinaceous material. The diagnoses were malignant (19 of 38 tumors; 50%), suspicious for malignancy (10 of 38 tumors; 26%), salivary gland neoplasm of uncertain malignant potential (7 of 38 tumors; 18%), and atypia of undetermined significance (2 of 38 tumors; 6%) according to the Milan System for Reporting Salivary Gland Cytopathology. Two malignant cases (2 of 40 tumors; 5%) were metastases. The neoplastic cells were immunoreactive for S100 (23 of 24 tumors), mammaglobin (18 of 18 tumors), GATA‐3 (13 of 13 tumors), AE1/AE3 (7 of 7 tumors), and vimentin (6 of 6 tumors). ETV6‐NTRK3 fusion was detected in 32 of 33 tumors by fluorescence in situ hybridization (n = 32) and next‐generation sequencing (n = 1).CONCLUSIONSFamiliarity with cytomorphologic features and the immunohistochemical/molecular profile of SC can enhance diagnostic accuracy.;

Cutaneous mast cell tumor in a captive Bush dog (Speothos venaticus): pathological and immunophenotypical aspects - case report

ABSTRACT A senile male captive bush dog (Speothos venaticus) presented a small perianal cutaneous nodule. Histologically, there was an ulcerated round cell tumor composed of well differentiated mast cells with abundant intracytoplasmic purple Giemsa-positive granules, with a diffuse eosinophilic infiltrate. Immunohistochemistry revealed that 30% of the neoplastic cells were positive for Kit in the cytoplasm and cell membrane, and all neoplastic cells were negative for MAC and CD3. Less than 10% of the neoplastic cells were positive for Ki67. At necropsy other primary tumors were identified in this animal, including an intestinal adenoma, an adrenal cortex adenoma and a testicular interstitial cell tumor.

Sclerosing Polycystic Adenoma of Salivary Glands: A Novel Neoplasm Characterized by PI3K-AKT Pathway Alterations-New Insights Into a Challenging Entity.

Sclerosing polycystic adenoma (SPA) is a rare salivary gland neoplasm originally thought to represent a non-neoplastic lesion. Recently we have encountered an index case of apocrine intraductal carcinoma of parotid gland of 62-year-old man with invasive salivary duct carcinoma component arising from SPA, a combination of tumor entities that has never been published so far. Here, we further explore the nature of SPA by evaluating 36 cases that were identified from the authors' consultation files. The patients were 25 females and 11 males aged 11 to 79 years (mean, 47.8 y). All tumors originated from the parotid gland. Their size ranged from 11 to 70 mm (mean, 28 mm). Histologically, all cases revealed characteristic features of SPA, such as lobulated well-circumscribed growth, focal hyalinized sclerosis, presence of large acinar cells with abundant brightly eosinophilic intracytoplasmic granules, and ductal components with variable cytomorphologic characteristics, including foamy, vacuolated, apocrine, mucous, clear/ballooned, squamous, columnar and oncocyte-like cells. In all cases, there were foci of intraluminal solid and cribriform intercalated duct-like epithelial proliferations with variable dysplasia which were positive for S100 protein and SOX10, and fully enveloped by an intact layer of myoepithelial cells. In addition, 14/36 cases (39%) had focal intraductal cribriform and micropapillary apocrine-type dysplastic epithelial structures composed of cells positive for androgen receptors and negative for S100/SOX10. The intraductal proliferations of both types showed focal mild to severe dysplasia in 17 cases (17/36; 47%). Two cases showed overt malignant morphology ranging from high-grade intraductal carcinoma to invasive carcinoma with an apocrine ductal phenotype. Next generation sequencing using ArcherDX panel targeting RNA of 36 pan-cancer-related genes and/or a TruSight Oncology 170/500 Kit targeting a selection of DNA from 523 genes and RNA from 55 genes was performed. Tumor tissue was available for molecular analysis in 11 cases, and 9 (9/11; 82%) of them harbored genetic alterations in the PI3K pathway. Targeted sequencing revealed HRAS mutations c.37G>C, p.(Gly13Arg) (2 cases) and c.182A>G, p.(Gln61Arg) (2 cases), and PIK3CA mutations c.3140A>G, p.(His1047Arg) (3 cases), c.1633G>A, p.(Glu545Lys) (1 case), and c.1624G>A, p.(Glu542Lys) (1 case). Moreover, mutations in AKT1 c.49G>A, p.(Glu17Lys) and c.51dup, p.(Tyr18ValfsTer15); c.49_50delinsAG, p.(Glu17Arg) (as a double hit) were found (2 cases). In addition, germinal and somatic mutation of PTEN c.1003C>T, p.(Arg335Ter); c.445C>T, p.(Gln149Ter), respectively, were detected. Gene fusions were absent in all cases. These prevalent molecular alterations converging on one major cancer-related pathway support the notion that SPA is a true neoplasm with a significant potential to develop intraluminal epithelial proliferation with apocrine and/or intercalated duct-like phenotype. The name SPA more correctly reflects the true neoplastic nature of this enigmatic lesion.

Candidatus Thiovulum sp. strain imperiosus: the largest free-living Epsilonproteobacteraeota Thiovulum strain lives in a marine mangrove environment.

A large (47.75 ± 3.56 µm in diameter) Thiovulum bacterial strain forming white veils is described from a marine mangrove ecosystem. High sulfide concentrations (up to 8 mM of H2S) were measured on sunken organic matter (wood/bone debris) under laboratory conditions. This sulfur-oxidizing bacterium colonized the organic matter, forming a white veil. According to conventional scanning electron microscope (SEM) observations, bacterial cells are ovoid and slightly motile by numerous small flagella present on the cell surface. Large intracytoplasmic internal sulfur granules were observed, suggesting a sulfidic-based metabolism. Observations were confirmed by elemental sulfur distribution detected by energy-dispersive X-ray spectroscopy (EDXS) analysis using an environmental scanning electron microscope (ESEM) on non-dehydrated samples. Phylogenetic analysis of the partial sequence of 16S rDNA obtained from purified fractions of this Epsilonproteobacteraeota strain indicates that this bacterium belongs to the Thiovulaceae cluster and could be one of the largest Thiovulum ever described. We propose to name this species Candidatus Thiovulum sp. strain imperiosus.

A rare case of multicentric eosinophilic granulocytic sarcoma as cause of hindlimb weakness and non‐regenerative anaemia in a minipig

AbstractA 6‐year‐old male, neutered minipig developed progressive hindlimb weakness and finally became recumbent. Clinical and laboratory examination revealed restricted hindlimb mobility and weight bearing with unimpaired reflexes and proprioception as well as marked non‐regenerative macrocytic anaemia, neutropenia and lymphocytopenia. Underlying bone marrow disease and haematopoietic neoplasia were assumed after exclusion of spinal disc herniation and infectious causes for anaemia. Despite stabilising therapy, the animal died 7 days later. Postmortem examination revealed multiple beige‐coloured nodules affecting many organs including the bone marrow and consisting of neoplastic round cells with intracytoplasmic eosinophilic granules. Using various histopathological stains and immunohistochemistry, the neoplastic cells were determined to be of eosinophil granulocyte origin. Granulocytic sarcoma is a rare form of myeloid neoplasia with only two published porcine cases. With the increasing popularity of minipigs as companion animals, extensive awareness and information concerning illnesses in these animals should be available to practitioners.

Characterization and plasticity of wharton's jelly mesenchymal stem cells of goat

Mesenchymal stem cells (MSCs), obtained from several anatomical sites, have already been described, characterized and used in therapeutic models for tissue repair. The umbilical cord mesenchymal stem cells, represented by cells from arteries and veins walls, as well as Wharton's jelly are easy to be obtained, highly available, require no invasive procedure, do not present risk to donors and do not present ethical limitation. The aim of this research was to analyze the plasticity of Wharton's jelly mesenchymal stem cells (WJ-MSCs) of goat, evaluating their behavior in vitro and characterizing them immunophenotypically. Thus, tests were performed on colony forming units, viability and cell growth curve, flow cytometry analysis and plasticity potential. Goat umbilical cord matrix cells exhibited fibroblastoid morphology with colony formation and self-renewal ability, always maintaining their undifferentiated state up to the eighth passage (P8). The growth curve kinetics exhibited the LAG, LOG, and DECAY phases, without displaying a PLATEAU phase. The plasticity assay demonstrated positive differentiation for osteogenic, adipogenic and chondrogenic lines, characterized by the synthesis of intracytoplasmic granules or extracellular matrix with the presence of calcium, lipids and proteoglycans. Flow cytometry demonstrated the expression of CD90 and CD105; absence of CD14 expression. It is concluded that the cell population isolated from the Wharton's jelly of goat constitutes a representative sample of mesenchymal stem cells, with great possibilities in the field of regenerative and reproductive medicine.

Pulmonar Granular Cell Tumor in a Horse

Background: The occurrence of neoplasms in horses is relatively low. Granular cell tumor is a seldom diagnosed neoplasm, usually benign, of mesenchymal origin. Controversies exist regarding its origin, which is possibly from Schwann cells or cells with neuroendocrine differentiation. Despite being one of the main primary neoplasms in the lungs of horses, the number of cases is low in comparison to that of secondary lung tumors. Thus, this study proposes to report the anatomopathological aspects in a horse with granular cell tumor of primary pulmonary origin. Case: An 11-year-old female Quarter Horse breed underwent exploratory right lateral thoracotomy after presenting with chronic respiratory changes. During the operation, tumor masses were found in the right and left caudal pulmonary lobes. Due to the severity of clinical respiratory signs and the extent of the lesions, the animal was subjected to euthanasia and anatomopathological examination. Upon necroscopic examination, a tumor mass was found in the middle third of the left caudal lobe, rounded to flattened, measuring 10.0 × 8.0 cm in height and length, white in color, of firm consistency, smooth and regular surface and rising to the lung surface. When sectioned, the mass showed to be composed of multiple firm and dense circular lobes, separated by a thin layer of connective tissue. The tumor invaded the lumen of nearby segmental and subsegmental bronchi, which were partially or totally obstructed by the mass. In the right lung, multiple similar nodules were observed, accompanied by peritumoral hemorrhage. Histopathological analysis of the new formation revealed a dense cluster of cells that expanded over the lung parenchyma. The neoplastic cells were pleomorphic, moderately cohesive, without defined borders, with abundant cytoplasm, densely eosinophilic and finely granular. Intracytoplasmic granules were well evidenced by periodic acid Schiff staining (PAS). The cell nucleus was rounded to oval, excentric, markedly basophilic and with dense chromatin. There was moderate anisocytosis and mild anisokaryosis, with rare mitotic figures. Immunohistochemical analysis revealed positive staining for anti-vimentin and anti-S100 antibodies, confirming the diagnosis of granular cell tumor.Discussion: Granular cell tumors have no predisposition as to breed, sex or age. However, most of the described cases are reported in female horses aged around 13 years. The advanced age of the diagnosed animals may be related to late definitive diagnosis, since the clinical signs are nonspecific and treated palliatively like other respiratory diseases. Macroscopically, this tumor is more common in the multinodular form and, as observed in this case, it has a greater capacity for infiltration. Histologically, the visualization of large, polygonal cells, with a wide cytoplasm containing eosinophilic granules leads to the diagnosis of granular cell tumor. However, PAS staining and immunohistochemical tests were essential for the diagnostic conclusion in this report, confirming the presence of cytoplasmic granules and the mesenchymal and neuroectodermal origin of this neoplasm, respectively. Thus, considering the low occurrence of pulmonary granular cell tumor, the description of this case contributes to the basis of the knowledge of medical-veterinary professionals about this tumor in its clinical and diagnostic aspects.Keywords: Schwann cells, immunohistochemistry, neoplasia, lung.Descritores: células de Schwann, imuno-histoquímica, neoplasia, pulmão.Título: Tumor de células granulares pulmonar em um equino

Is immunohistochemistry always the panacea to morphologic mimics? Two, distinct soft tissue tumors exhibiting alveolar pattern and TFE3 immunoreactivity

Alveolar soft part sarcoma (ASPS) and certain perivascular epithelioid cell neoplasms (PEComas) exhibit overlapping histopathological features, including immunohistochemical expression of TFE3, as well as TFE3 gene rearrangement. PEComas with an epithelioid morphology are known to exhibit variable immunoexpression of muscle markers. At the same time, aberrant immunoreactivity of HMB45 immunostain, which is invariably, used to substantiate a diagnosis of a PEComa, has been reported in various other tumors. Herein, we discuss two rare cases of soft tissue tumors with overlapping morphological and immunohistochemical features. Case1: A 34-year-old male underwent a biopsy for a recurrent, right-sided nasal polyp. Biopsy showed polygonal tumor cells, containing prominent nucleoli, arranged in a "nesting-type"/alveolar growth pattern. Immunohistochemically, tumor cells displayed TFE3 positivity and an aberrant positivity for HMB45. Special stain (PAS-diastase) highlighted intracytoplasmic granules and crystals. Diagnosis of ASPS was offered. Furthermore, the tumor cells displayed TFE3 gene rearrangement. Case 2: A 29-year-old female underwent an aural polypectomy. Microscopic examination revealed a tumor with a "nesting-type"/alveolar arrangement of tumor cells with vacuolated cytoplasm, arranged around thin-walled blood vessels. Immunohistochemically, tumor cells were diffusely positive for HMB45 and TFE3 and focally for SMA. A diagnosis of a PEComa was offered. This report constitutes the first documentation of aberrant HMB45 immunoreactivity in case of ASPS, and one of the first reported cases of a PEComa in the ear. It emphasizes the value of integrating clinicopathological features with immunohistochemical and molecular results in differentiating two rare, but distinct soft tissue tumors with overlapping features. An exact diagnosis of both these tumor entities has therapeutic implications.

Whole-exome sequencing reveals novel vacuolar ATPase genes' variants and variants in genes involved in lysosomal biology and autophagosomal formation in oral granular cell tumors.

Granular cell tumors (GCTs) are rare neuroectodermal soft tissue neoplasms that mainly affect the skin of the upper limbs and trunks and the oral cavity. GCTs are derived from Schwann cells and, ultrastructurally, their intracytoplasmic granules are considered autophagosomes or autophagolysosomes and are consistent with myelin accumulation. In this study, a convenience set of 22 formalin-fixed, paraffin-embedded samples of oral GCTs, all but one sample located at the tongue, was screened for mutations by whole-exome (WES) or targeted sequencing. WES revealed two novel variants in genes of the vacuolar ATPase (V-ATPase) complex: ATP6AP1 frameshift c.746_749del, leading to p.P249Hfs*4, and ATP6V1A non-synonymous c.G868A, leading to p.D290N. Each of these mutations occurred in one case. With regard to the samples that were wild type for these V-ATPase variants, at least two samples presented variants in genes that are part of endosomal/lysosomal/autophagosomal networks including ABCA8, ABCC6, AGAP3, ATG9A, CTSB, DNAJC13, GALC, NPC1, SLC15A3, SLC31A2, and TMEM104. Although the mechanisms involved in oral GCT initiation and progression remain unclear, our results suggest that oral GCTs have V-ATPase variants similarly to GCTs from other tissues/organs, and additionally show variants in lysosomes/endosomes/autophagosomal genes.

Loss of histone H3 trimethylation on lysine 27 and nuclear expression of transducin-like enhancer 1 in primary intracranial sarcoma, DICER1-mutant.

Primary intracranial sarcoma, DICER1-mutant is a recently described central nervous system tumour with specific genomic and DNA-methylation profiles. Although some of its histological features (focal spindle-cell morphology, intracytoplasmic eosinophilic granules, and focal heterologous differentiation) are common across most reported cases, the presence of significant histological variability and the lack of differentiation pose diagnostic challenges. We aim to further define the immunoprofile of this tumor. We reviewed the clinical history and performed immunohistochemistry for glial fibrillary acidic protein, oligodendrocyte transcription factor 2, SOX2, SOX10, S100, histone H3 trimethylated on lysine 27 (H3K27me3), desmin, myogenin, CD99, epithelial membrane antigen (EMA) and transducin-like enhancer of split 1 (TLE1) on six primary intracranial sarcomas, DICER1-mutant, with appropriate controls. Targeted exome sequencing was performed on all cases. The sarcomas showed diffuse (n=4), mosaic (n=1) or minimal (≤5%, n=1) loss of H3K27 trimethylation and nuclear TLE1 expression (n=6). Four had immunohistochemical evidence of myogenic differentiation. SOX2, SOX10, S100 and EMA were negative; CD99 expression ranged from focal cytoplasmic (n=4) to crisp diffuse membranous (n=2). One tumour had focal cartilaginous differentiation. Similar immunohistochemical findings were observed in a pleuropulmonary blastoma (albeit with focal TLE1 expression), a DICER1-related pineoblastoma, and an embryonal tumour with a multilayered rosette-like DICER1-related cerebellar tumour. Targeted exome sequencing confirmed the presence of pathogenic biallelic DICER1 mutations in all tumours included in this study. We conclude that H3K27me3 and TLE1 immunostains, when utilised in combination, can be helpful diagnostic markers for primary intracranial sarcoma, DICER1-mutant.

Metastatic Alveolar Soft Part Sarcoma to the Breast: A Case Report

Abstract Introduction/Objective Metastases to the breast are rare (less than 3% of all breast malignancies). In adults, malignant melanoma is the most common type of metastasis followed by carcinomas from various primary sites. Here, we describe a case of metastatic alveolar soft part sarcoma (ASPS) to the breast. Only a handful similar presentations are reported in the literature. Methods Here we describe the case of a 43-year-old female patient with a recent diagnosis of left base of tongue alveolar soft part sarcoma (in an outside hospital), presenting with a palpable mass in her left breast. Sonographic study of the left breast demonstrated a 1.4 cm oval hypoechoic mass with partially microlobulated margins at 1 o’clock. Results Histopathologic examination of the ultrasound guided core biopsy showed a “pink” neoplasm, composed of plump epithelioid tumor cells with an eosinophilic and granular cytoplasm, round to oval nuclei and conspicuous nucleoli. They are arranged in organoid nests separated by sinusoidal spaces. An immunohistochemical study shows the tumor cells to be negative for keratin AE1/AE3, keratin 7, keratin 5/6, GATA-3, Pax-8, estrogen receptor, HER2, p63, S100 and CD117. FISH test for TFE3 (Xp 11.23) is positive. PAS with diastase staining highlights the intracytoplasmic granules. Theses morphologic, clinical and molecular findings confirm the diagnosis of metastatic ASPS. Conclusion The differential diagnosis of “pink” tumors of the breast include primary tumors like secretory carcinoma and apocrine carcinoma and metastatic lesions of renal, thyroid, skin (melanoma), oral cavity and soft tissue. Although extremely rare, in the right clinical context, metastatic ASPS to the breast can occur and should be included in the differential diagnosis.

Lectin characterization of the gastrointestinal tract of three Nigerian passerine birds

The avian gastrointestinal tract was characterized using lectin cytochemistry Concanavalia agglutinin (Con A) and Arachis hypogea agglutinin, Peanut agglutinin (PNA). The apical cell boundaries of surface epithelial cells of both the proventriculus and ventriculus, the duct and glandular neck cells of the proventriculus, the intestinal brush borders, the surface epithelial cells of the sheep abomasum and the chief cells of the sheep abomasum were stained by Con A and PNA. The intracytoplasmic granules of the duct and glandular neck cells of the proventriculus, those of the chief or principal cells of the ventriculus, those of the goblet cells of the ileum, colon and cloaca and those of the chief and surface epithelial cells of the sheep abomasum were stained by PNA. Gastro-intestinal endocrine cells and the parietal cells of both the avian gut and the sheep abomasum were not stained by either lectins. The cytochemical results indicated that those cells stained by the two lectins have both a-D- mannose or a-D-glucose and b-galactose- (1,3)-N-acetyl-galactosamine residues in their membranes. Those stained by either of the two lectins had either of the two sugars as components of their cell membrane and their granules. Goblet cells were heterologous. The duct and glandular neck cells of the proventriculus, the chief cells of the ventriculus, the goblet cells of the ileum, colon, cloaca, and the chief and surface epithelial cells of the sheep abomasum had similar intracytoplasmic granules.