Unusual Pathology Research Articles

Research-Relevant Conditions and Pathology of Laboratory Mice, Rats, Gerbils, Guinea Pigs, Hamsters, Naked Mole Rats, and Rabbits.

Animals are valuable resources in biomedical research in investigations of biological processes, disease pathogenesis, therapeutic interventions, safety, toxicity, and carcinogenicity. Interpretation of data from animals requires knowledge not only of the processes or diseases (pathophysiology) under study but also recognition of spontaneous conditions and background lesions (pathology) that can influence or confound the study results. Species, strain/stock, sex, age, anatomy, physiology, spontaneous diseases (noninfectious and infectious), and neoplasia impact experimental results and interpretation as well as animal welfare. This review and the references selected aim to provide a pathology resource for researchers, pathologists, and veterinary personnel who strive to achieve research rigor and validity and must understand the spectrum of "normal" and expected conditions to accurately identify research-relevant experimental phenotypes as well as unusual illness, pathology, or other conditions that can compromise studies involving laboratory mice, rats, gerbils, guinea pigs, hamsters, naked mole rats, and rabbits.

A Rare Case of Prostatic Utricle with Crossover Vas Deferens in Children

Background: A prostatic utricle (PU) is an unusual pathology with most patients being asymptomatic. However, approximately 29% of patients may show lower urinary tract symptoms, recurrent urinary tract infections (UTI), postvoid dribbling, urethral discharge, epididymo-orchitis, stones, and secondary incontinence caused by urine trapping in the pouch and urinary retention. The standard treatment is through surgical resection, but it is only offered to patients with symptoms. Case summary: We report a case involving a six-year-old boy with congenital hypothyroidism and penoscrotal hypospadias who had previously undergone onlay urethroplasty for the proximal shaft, chordee release, orchidopexy for bilateral undescended testis, and laparoscopic herniorrhaphy for left inguinal hernia. However, the patient later evolved the repetition of UTI and right epididymo-orchitis. Cyclic voiding cystourethrography confirmed the presence of a cystic lesion communicating with the prostatic urethra from the utricle. The PU was then excised laparoscopically. The utricle was identified posterior to the bladder, and insertions of the vas deferens crossover into the utricle were detected by laparoscopy. The post-procedure course was uneventful. Conclusions: Laparoscopic resection of PUs offers a better exposure field, improved wound appearance, complete resection, and reduces the incidence of complications. During laparoscopy, the PU was clearly distinguished from the bladder or other pelvic organs. An incidental finding of vas deferens crossover has rarely been reported. A combined cystoscopy and laparoscopy for PU resection is executable, safe, and valid in this patient population.

New anomalies and pathologies in the caudal region of the lizard’s axial skeleton

Currently, more than 58 skeletal anomalies and pathologies are known in the recent Squamata reptiles. In this paper, eight pathologies of a complex nature are described in Agamidae and Lacertidae: Paralaudakia caucasia (Eichwald, 1831) and Lacerta agilis Linnaeus, 1758. Description of tail pathologies was carried out based on the analysis of X-ray images and on the results of computer microtomography. In the specimen of P. caucasia (ЗИН 19116.1) complete ablation of the caudal vertebra was revealed, which provoked the detachment of chevron and the proliferation of soft tissues. In some Agamidae, after pseudoautotomy, partial ablation of the caudal vertebra occurs to promote wound healing. Complete ablation of the distal caudal vertebra has not been previously reported in literature. In females of L. agilis, deformation of the right transverse process of the vertebra with “false bifurcation” without the formation of a cartilaginous tube (VOLSU 98.2), scoliosis, hematoma and callus on the cartilaginous tube were noted, as well as the absence of an autotomy plane in the postpygal vertebra (ZIN 31549). An unusual pathology in L. agilis (ZIN 31549) is the absence of an autotomy plane in the postpigal vertebra and of its anterior neural spine. The loss of the plane of autotomy during ontogeny is characteristic of some Iguanidae, but it has not been previously noted in Lacertidae. The described cases of anomalies expand the spectrum of known pathologies in reptiles.

EP.FRI.543 A rare case of acute jejuno-jenual intussusception in a patient with Roux-en-Y bypass secondary to a benign polyp

Abstract Introduction Roux-en-Y Gastric bypass (REYGB) amounts for a third of surgical bariatric interventions. Small bowel obstruction (SBO) is a long-term complication in REYGB and can be caused by intussusception of bowel, in approximately 0.5% of procedures. Intussusception in REYBG is mostly attributed to dysmotility. This report demonstrates a rare case of intussusception in REYGB secondary to a benign polyp. Case description A 45 year old female, three years post REYGB, presented to A&E with acute, extreme upper abdominal pain, with three days absolute constipation. She was tender on examination with normal blood tests. CT scan demonstrated small bowel intussusception. Initial concerns were of intussusception of the jejuno-jejunostomy anastomosis causing SBO. She had an exploratory laparotomy, which confirmed intussusception, however this was 20cm distal to the jejuno-jejunostomy. Bowel was gently reduced, and deemed viable. On thorough run-through, a small segment at the transition point, was considered abnormal on palpation. This region was resected and a 1x1cm intraluminal polyp was identified as the causative lead point. The patient did well postoperatively. Discussion Small bowel intussusception in adults is typically attributed to pathological lead point, such as benign or malignant lesions. Intussusception in REYBG is a rare but well-documented cause of intestinal obstruction, usually attributed to dysmotility, secondary to ectopic pacemaker cells particularly around anastomoses. In this case, the intussusception was caused by an unusual pathology separate from the jejuno-jejunal anastomosis. We recommend thorough examination of all adjacent bowel to exclude lesions, in this case a polyp, which could result in recurrence.

EP.TU.439Falciform ligament torsion – a rare cause of the acute abdomen

Abstract The falciform ligament attaches the liver to the anterior abdominal wall and diaphragm. Acute falciform ligament related pathology is rare. In this case report we present a case of acute fat necrosis related to the falciform ligament. A 53 year old women presented with acute upper abdominal pain localised to the right hypochondrium. He was tender to palpation in the same region with a positive Murphy’s sign. A provisional diagnosis of acute cholecystitis was made. Blood work revealed raised inflammatory markers but normal liver function tests. Abdominal ultrasound revealed no gallbladder pathology nor gallstones. Thus computed tomogram (CT) scan of the abdomen was performed, showing hyper-attenuation rim signal present within the inferior aspect of the falciform ligament consistent with local vascular occlusion. The patient was managed with intravenous antibiotics with liberal analgesia and went on to make a successful recovery. Only 10 cases have been reported in the literature related to falciform ligament necrosis. We present this unusual pathology encountered on our acute surgical take, to alert surgeons to this rare diagnosis and provide a review of the literature and provide detail of how such a pathology manifests on CT scan.

887 Suspected malignancy and unusual pathology in a severe case of Lemierre’s syndrome

Abstract Lemierre’s syndrome, although rare, is a potentially fatal condition, usually associated with the anaerobic bacterium, Fusobacterium necrophorum. This case describes a previously healthy 59-year-old female, who had a three-week history of pharyngitis and dysphagia. She presented to the emergency department with a left neck swelling and fever. A CT scan showed a 3 cm left level IV low-density suspected neck mass or necrotic node. There were multiple pulmonary nodules raising suspicion for metastases. Blood cultures were positive for Streptococcus constellatus and Dialister pneumosintes. The scan was further reviewed by a Head and Neck specialist radiologist and an Oral and Maxillofacial consultant, which highlighted a peritonsillar abscess and filling defect in the left internal jugular vein. A conclusive diagnosis of Lemierre’s syndrome with septic pulmonary emboli was established. She improved clinically with IV antibiotics in conjunction with daily enoxaparin injections. We believe that this is the first reported case of Lemierre’s syndrome associated with Dialister pneumosintes. A high index of suspicion is essential in cases of persistent pharyngitis and sepsis in an otherwise healthy individual, in order to promptly diagnose the condition and initiate treatment.

S1933 A Submucosal Avatar: An Interesting Intervention for an Unusual Pathology of Polypoid Colonic Leiomyoma

S1933 A Submucosal Avatar: An Interesting Intervention for an Unusual Pathology of Polypoid Colonic Leiomyoma

Typical Orbital Cellulitis Presentation in Newborn

Orbital cellulitis represents a frequent cause of inflammation of the orbit, constituting a medical emergency that requires multidisciplinary management. We present a case of a newborn with clinic of volume increase in right bipalpebral region and fever of 24 hours of evolution. Physical examination reveals proptosis of right eye, increase of bipalpebral volume that prevents the opening of the eyeball in its entirety with signs of flushing and purulent eyelid margin secretion. Laboratories report leukocytosis and reactive thrombosis; orbital tomography scan shows right periorbital swelling and edema, diffuse increase of extra and intraconal post-septal fat density, suggestive findings of right orbital cellulitis, covered with vancomycin and cefotaxime; subsequently requires abscess drainage where Staphylococcus aureus methycilin- resistant is isolated. Being an unusual pathology in this age group, the publication of this case is recommended. Key word: Celullitis, orbital abcess, new born

The pediatric stomach - congenital abnormalities.

Diagnostic imaging of the pediatric stomach often provides a challenge for practicing radiologists. Radiologists should be aware of relatively unusual congenital pathology, especially when imaging very young children with gastrointestinal symptoms. We review congenital pathology of the pediatric stomach.

Colorectal neuroendocrine carcinoma with squamous cell differentiation: a rare and unusual tumour

Background: Neuroendocrine carcinoma (NEC) of the colorectum is rare, accounting for 0.4% of all colorectal neoplasms.1 Squamous cell carcinoma (SCC) of the gastrointestinal tract is also a rare entity and accounts for 0.1–0.25% per 1000 cases of colorectal carcinoma.2 World Health Organization (WHO) classification defines mixed adeno-neuro-endocrine carcinoma as a neoplasm with both exocrine and neuroendocrine components, with each component exceeding 30%. Aim: We present a rare case of a patient with colorectal neuroendocrine carcinoma with squamous differentiation. Method: An 86-year-old gentleman presented with right sided abdominal pain. A colonic mass was noted on CT scan with multiple liver lesions. Subsequent right hemicolectomy revealed an obstructive hepatic flexure tumour. Results and conclusions: Histopathological examination of the mass revealed a high grade neuroendocrine carcinoma (NEC) with diffuse sheets and cords of epithelial cells with crowded nuclei, scant cytoplasm and frequent mitotic figures (23 per 10 high-power field). Amongst the NEC component, small areas (less than 30% of the tumour volume) comprising larger epithelial cells with abundant eosinophilic cytoplasm and areas suggestive of keratinisation were noted. The NEC component was positive for synaptophysin and CD56 immunohistochemistry with a Ki67 proliferation index of 80–90% and negative for P40 and CK5/6 immunohistochemistry. In contrast, the areas with large eosinophilic cells were positive for P40 and CK5/6 immunohistochemistry, whilst negative for synaptophysin and CD56 immunohistochemistry. The tumour exhibited aggressive behaviour with lymphovascular, perineural and venous invasion and lymph node metastases. Neuroendocrine carcinomas and squamous cell carcinomas of the colorectum are rare and extremely aggressive neoplasms3 on their own merits. This phenomenon of mixed neuroendocrine carcinoma with squamous cell differentiation is an unusual and rare pathology which lacks evidence-based guidelines for therapy. It is worth documenting as the optimal therapeutic strategy remains the main challenge.

Solitary plasmacytoma of the maxilla: A rare case report of identification and management within an oral surgery department

AbstractPlasmacytoma is a rare malignant tumour originating from the plasma cells. This may present itself in the bone marrow (myelomatous) as a solitary bone plasmacytoma or in the soft tissues, as an extramedullary plasmacytoma. Solitary bone plasmacytomas in the head and neck region are very uncommon and initial symptoms may be non‐specific and vague. However, the risk of progression towards multiple myeloma with these conditions is high, and therefore early diagnosis is essential for positive therapy outcomes. An 81‐year‐old patient presented with a pedunculated soft tissue mass in the upper left maxilla. This demonstrated symptoms in keeping with a pyogenic granuloma; however, the rapid growth and haemorrhagic nature raised concerns. Histological examination of the maxillary soft tissue mass revealed dense plasma cell infiltrate, consistent with a solitary plasmacytoma. Extensive investigations were performed to exclude multifocal involvement. Treatment involved complete surgical excision and radiotherapy. The patient remained stable and progression free at 6‐month review. The objective of this clinical case report is to highlight this unusual oral pathology to avoid incorrect diagnosis.

Molecular Pathology Analysis of SARS-CoV-2 in Syncytiotrophoblast and Hofbauer Cells in Placenta from a Pregnant Woman and Fetus with COVID-19.

A small number of neonates delivered to women with SARS-CoV-2 infection have been found to become infected through intrauterine transplacental transmission. These cases are associated with a group of unusual placental pathology abnormalities that include chronic histiocytic intervillositis, syncytiotrophoblast necrosis, and positivity of the syncytiotrophoblast for SARS-CoV-2 antigen or RNA. Hofbauer cells constitute a heterogeneous group of immunologically active macrophages that have been involved in transplacental infections that include such viral agents as Zika virus and human immunodeficiency virus. The role of Hofbauer cells in placental infection with SARS-CoV-2 and maternal-fetal transmission is unknown. This study uses molecular pathology techniques to evaluate the placenta from a neonate infected with SARS-CoV-2 via the transplacental route to determine whether Hofbauer cells have evidence of infection. We found that the placenta had chronic histiocytic intervillositis and syncytiotrophoblast necrosis, with the syncytiotrophoblast demonstrating intense positive staining for SARS-CoV-2. Immunohistochemistry using the macrophage marker CD163, SARS-CoV-2 nucleocapsid protein, and double staining for SARS-CoV-2 with RNAscope and anti-CD163 antibody, revealed that no demonstrable virus could be identified within Hofbauer cells, despite these cells closely approaching the basement membrane zone of the infected trophoblast. Unlike some other viruses, there was no evidence from this transmitting placenta for infection of Hofbauer cells with SARS-CoV-2.

Lipoma no Septo Interventricular – Relato De Caso

Primary cardiac tumors are a rare but mostly benign pathology found in up to 0.03% of autopsies. Among these benign tumors, with an incidence of 8.5%, lipomas are often located in the interatrial septum. When located in the interventricular septum, they are considered an even more unusual pathology with an unknown real prevalence. In most cases, the diagnosis is made incidentally on cardiovascular imaging and confirmed by histopathological examination. They are more commonly asymptomatic or feature nonspecific symptoms, but these lipomas can progress with arrhythmias, valve dysfunction, heart failure, and death, which highlights the importance of cardiovascular imaging methods in the differential diagnosis and to guide appropriate therapy. This report describes the case of a patient with an incidental echocardiographic finding of a cardiac mass located in the interventricular septum, followed by cardiac magnetic resonance imaging to better characterize the lesion and demonstrate its characteristics compatible with lipoma.

Perforated Appendicitis within the Sac of a Recurrent Incisional Hernia

Perforated hernial appendicitis rarely occurs with an incidence of 0.008%. We present a case of a young obese woman, a known hypertensive, who presented with abdominal pain, fever, and a tender abdominal swelling over a previous lower midline incision scar. She was thought to have a strangulated recurrent incisional hernia and was offered an emergency laparotomy. Intraoperatively, she was found to have a massive multiloculated hernia sac with the caecum, ruptured appendicitis, and abscess within a locus of the sac. Her ascending colon was mobile. The abscess was drained, appendicectomy was done, hernia repair deferred, and wound closure effected. Such atypical presentation poses a diagnostic challenge. We seek to increase awareness of this condition and contribute to the medical literature surrounding this unusual pathology.

Cardiac hydatid disease: An unusual pathology in an st-elevation myocardial infarction patient

Hydatid disease, is an infection caused by the larval stage (metacestode) of the cestode Echinococcus granulosus. In humans it may result in a wide spectrum of clinical manifestations ranging from asymptomatic infection to severe, even fatal disease. Echinococcal cysts are found in the liver in approximately 70 % of cases, and the lungs in approximately 25 % of cases. Cardiac hydatid disease is seen in 0.5–5% of total hydatid disease patients, the present case highlights the unusual presentation of Hydatid cyst in a different clinical scenario.

Finding unusual pathology in usual clinical presentation: Huge implications for therapy

Finding unusual pathology in usual clinical presentation: Huge implications for therapy

Eagle syndrome: a review of the literature

Introduction: Eagle syndrome (ES) is a very unusual pathology caused by the elongation of the styloid process (SP), it can cause various clinical symptoms, the size ranges between approximately 25 to 30 mm, when it exceeds these parameters it is classified as attached as elongated process. Objective: To describe the general aspects, diagnosis and treatment of Eagle Syndrome. Development: Eagle Syndrome is a complex pathology that requires extensive knowledge of its signs and symptoms to establish a correct diagnosis and subsequently an adequate treatment. Conclusion: Contrast-enhanced CT examination can easily diagnose this disease, it is important to consider a differential diagnosis. Surgery is the best alternative when conservative management fails, it reduces morbidity. Recognizing diagnostic tools, applicable images, and alternatives is crucial for successful treatment.

Thinking Outside the Peritoneal Cavity: A Novel Approach to a Rare Disease

Study Objective The objective of this video is to describe a novel surgical approach to hepatic endometriosis invading the retroperitoneum. Design Video case presentation. Setting Tertiary care academic medical center. Patients or Participants 61 year old woman with aggressive recurrent endometriosis who presents with new right upper quadrant pain and a MRI showing a sub-hepatic mass consistent with an endometriosis lesion. Interventions Laparoscopic excision of the endometriosis nodule using a posterior retroperitoneal approach. Measurements and Main Results N/A Conclusion Hepatic endometriosis is a very rare form of extrapelvic endometriosis. Sub-hepatic lesions, including those invading through Morrison's pouch, can be safely accessed via the posterior retroperitoneal approach during laparoscopy. When faced with a complicated patient and unusual pathology, it is crucial to be creative, consider all surgical approaches and seek help outside your surgical expertise.

Exploring the Retropubic Space: Resection of Urethral Leiomyoma

Study Objective demonstrate the technique of developing the retropubic space, review relevant anatomy, and to discuss the differential diagnosis of a periurethral mass. Design Stepwise demonstration of retropubic space dissection and resection of a urethral leiomyoma with narrated video footage. Setting Academic medical center. Patients or Participants 63 year old woman with history of hysterectomy with bilateral salpingo-oophorectomy performed for endometriosis presented with 2 years of chronic pelvic pain. The patient reported feeling constant pressure on her bladder, which was particularly noticeable when voiding. Interventions Robotic-assisted dissection of the retropubic space and resection of periurethral mass. Measurements and Main Results The periurethral mass was resected and pathology revealed benign leiomyoma. The patient had improvement in her urinary-associated pain symptoms. Conclusion Gynecologic surgeons should feel comfortable developing the retropubic space because this dissection is necessary for many procedures such as retropubic suspension, ureteral reimplantation, psoas hitch, and removal of retropubic mesh. Understanding anatomy maximizes safety and success when tackling unusual pathology. demonstrate the technique of developing the retropubic space, review relevant anatomy, and to discuss the differential diagnosis of a periurethral mass. Stepwise demonstration of retropubic space dissection and resection of a urethral leiomyoma with narrated video footage. Academic medical center. 63 year old woman with history of hysterectomy with bilateral salpingo-oophorectomy performed for endometriosis presented with 2 years of chronic pelvic pain. The patient reported feeling constant pressure on her bladder, which was particularly noticeable when voiding. Robotic-assisted dissection of the retropubic space and resection of periurethral mass. The periurethral mass was resected and pathology revealed benign leiomyoma. The patient had improvement in her urinary-associated pain symptoms. Gynecologic surgeons should feel comfortable developing the retropubic space because this dissection is necessary for many procedures such as retropubic suspension, ureteral reimplantation, psoas hitch, and removal of retropubic mesh. Understanding anatomy maximizes safety and success when tackling unusual pathology.

Megadolicocolon de presentación poco usual en un paciente de edad avanzada: a propósito de un caso

El megadolicocolon es una patología inusual, de etiología no bien esclarecida, tal parece ser de origen congénito, se presenta con frecuencia en recién nacidos y lactantes con vólvulos de colon. Su incidencia es variable y se encuentra entre 1,9 y 28,5 %.
 Este reporte de caso es excepcional debido a que se presenta con una evolución y comportamiento agresivo de la enfermedad, pues se trata de un paciente de edad avanzada, con antecedente de sigmoidopexia y cuadro clínico de 7 meses de evolución consistente en estreñimiento crónico y exacerbación difusa de dolor abdominal incapacitante, quién requirió procedimiento quirúrgico de emergencia para su manejo.