Rare Lesion Research Articles

Non-Neoplastic Thoracic Cysts: A Clinicopathologic Study of 136 Cases.

Benign cysts of the thoracic cavity represent a group of rare lesions, the spectrum of which is expanding. Most of these are congenital in nature, secondary to abnormal development during embryogenesis while a smaller subset represents acquired lesions. We retrospectively reviewed the clinicopathologic features of 136 patients with thoracic cysts that were treated in our institution over a span of 20 years. The patients were 85 female and 51 male patients with an average age of 51 years. Eighty-four of the patients were asymptomatic (62%), the remainder mainly presented with chest pain, shortness of breath, or cough. Surgical resection was performed in 123 patients while 12 patients were treated with aspiration only and 1 underwent core biopsy. The cyst size ranged from 0.5 to 14.8cm (mean, 4.4cm); histologically, the lesions included 50 thymic cysts (28 multilocular; 22 unilocular), 37 bronchogenic cysts, 23 pleuropericardial cysts, 12 unclassified cysts, 6 Müllerian cysts, 5 enteric cysts, and 3 parathyroid cysts. Clinical follow-up revealed that 97 patients were alive and well 4 months to 37 years after initial diagnosis; 25 patients were lost to follow-up and 14 patients died of unrelated causes. The current study is one of the largest studies on the subject with emphasis on clinicopathologic characteristics. This series has a higher incidence of thymic cysts compared with prior publications and covers a wider spectrum of different histologic types than previously reported.

A case report of nasal lobular capillary hemangioma

Nasal lobular capillary hemangiomas are rare and benign tumors of the paranasal sinuses. The aim is to study a case of nasal lobular capillary hemangioma. Here, a case of a 29-year-old male patient who presented to ear, nose and throat outpatient department (ENT OPD) with complaints of multiple episodes of epistaxis and left nasal obstruction for the past year. After proper radiological, cytological and hematological assessment, an excision biopsy from the mass of the left nasal cavity was performed which was suggestive of lobular capillary hemangioma. The patient has been operated on via lateral rhinotomy approach and nasal mass was found to be originated from the anterior ethmoidal artery, removed piecemeal and complete excision was done. Nasal lobular capillary hemangioma is quite a rare lesion of unknown etiology especially when it occurs in the nasal cavity. It should always be considered in the differential diagnosis of vascular lesions within the nasal cavity. Complete excision of the mass with a lateral rhinotomy approach gives an excellent outcome.

Lymph Node Metastases from Non-Melanoma Skin Cancer of the Head and Neck.

Non-melanoma skin cancer (NMSC) represents the most common malignancy in the world, comprising exceedingly common lesions such as basal cell carcinoma (BCC) and cutaneous squamous cell carcinoma (cSCC) and rare lesions such as Merkel cell carcinoma. Risk factors are widely recognized and include ultraviolet (UV) light exposure, radiation exposure, immunosuppression, and many others. As a whole, survival and functional outcomes are favorable, but each histopathological subtype of NMSC behaves differently. Treatment regimens for the primary site usually include wide surgical excision and neck dissection in cases of clinically involved metastatic lymph nodes. The elective management of draining nodal basins, however, is a contested topic. Nearly all subtypes, excluding BCC, have a significant risk of lymphatic metastases, and have been studied with regard to sentinel lymph node biopsy (SLNB) and elective neck dissection. To date, no studies have definitively established a true single standard of care, as exists for melanoma, for any of the NMSCs. As a result, the authors have sought to summarize the current literature and identify indications and management options for the management of the cervical lymphatics for each major subtype of NMSC. Further research remains critically necessary in order to develop complete treatment algorithms.

Retroperitoneal Bronchogenic Cyst: Imaging and Pathophysiological Review

Bronchogenic cysts are rare lesions that form during early embryogenesis and are commonly located in the mediastinum. Retroperitoneally located bronchogenic cysts are an exceptionally rare entity. These are most commonly found incidentally on imaging. We will review the unique imaging and histopathological findings of this entity and discuss why prophylactic surgery is considered the treatment of choice. By reviewing retroperitoneal bronchogenic cysts, we aim to educate clinicians regarding the presentation, investigations, imaging characteristics, and treatment of this exceeding rare entity.

Rare Solid Pancreatic Lesions on Cross-Sectional Imaging.

Several solid lesions can be found within the pancreas mainly arising from the exocrine and endocrine pancreatic tissue. Among all pancreatic malignancies, the most common subtype is pancreatic ductal adenocarcinoma (PDAC), to a point that pancreatic cancer and PDAC are used interchangeably. But, in addition to PDAC, and to the other most common and well-known solid lesions, either related to benign conditions, such as pancreatitis, or not so benign, such as pancreatic neuroendocrine neoplasms (pNENs), there are solid pancreatic lesions considered rare due to their low incidence. These lesions may originate from a cell line with a differentiation other than exocrine/endocrine, such as from the nerve sheath as for pancreatic schwannoma or from mesenchymal cells as for solitary fibrous tumour. These rare solid pancreatic lesions may show a behaviour that ranges in a benign to highly aggressive malignant spectrum. This review includes cases of an intrapancreatic accessory spleen, pancreatic tuberculosis, solid serous cystadenoma, solid pseudopapillary tumour, pancreatic schwannoma, purely intraductal neuroendocrine tumour, pancreatic fibrous solitary tumour, acinar cell carcinoma, undifferentiated carcinoma with osteoclastic-like giant cells, adenosquamous carcinoma, colloid carcinoma of the pancreas, primary leiomyosarcoma of the pancreas, primary and secondary pancreatic lymphoma and metastases within the pancreas. Therefore, it is important to determine the correct diagnosis to ensure optimal patient management. Because of their rarity, their existence is less well known and, when depicted, in most cases incidentally, the correct diagnosis remains challenging. However, there are some typical imaging features present on cross-sectional imaging modalities that, taken into account with the clinical and biological context, contribute substantially to achieve the correct diagnosis.

56 Epidermoid cyst mimicking appendiceal mucocoele

Abstract Background Congenital epidermoid cysts found in internal organs are thought to arise from displaced or implanted ectoderm during embryonic development. Their histogenesis differs from that of acquired cysts which are associated with trauma or iatrogenic implantation. Epidermoid cysts related to caecum or appendix are rare. The present case describes the largest caecal epidermoid cyst reported in the English literature so far in a patient with no previous history of surgery or trauma. Case report A man in his late thirties presented with a three-week history of dull right-sided abdominal pain. Physical examination revealed right flank fullness and subsequent CT scan showed a large right-sided cystic mass adjacent to caecum. The appendix could not be visualised separately and the mass was thought to be either an appendiceal mucocoele or an inclusion cyst. Cryptorchidism was excluded. Due to concerns of possible mucocoele that could lead to pseudomyxoma peritonei, laparotomy was performed and the cyst was excised intact with an ileocaecectomy. The specimen weighed 1.8kg and was 120 x 105 x 95mm in size. Histological findings were consistent with an epidermoid cyst inseparable from caecum and appendix, visibly distinct from the appendiceal wall stretching over it. Conclusion Epidermoid cysts related to caecum or appendix are rare benign lesions. In the present case, the cyst was safely excised via an open ileocaecetomy, based on its location and concern for an appendiceal mucocoele. Ileocaecectomy or segmental colectomy with primary anastomosis can be safe surgical management options for caecal cysts in an otherwise healthy patient.

Clinicopathological Evaluation of Gall-Bladder Lesions in Cholecystectomy Specimens with Special Emphasis to Incidentally Detected Cases of Gall-Bladder Carcinoma Along with Immunohistochemical Study of Cytokeratin 7 and Cytokeratin 20

Introduction: Cholecystectomy specimens show wide clinicopathological spectrum varying from common non neoplastic diseases to rare neoplastic lesions and histopathological examination the gold standard for final diagnosis. Gall Bladder Cancers (GBCs) are rare and account for 0.5% to 1.09% of all gall bladder lesions. It is either clinically suspected or incidentally diagnosed following cholecystectomy. Methods: It was a Hospital based cross-sectional Study. All cases diagnosed clinically & radiologically and operated as cholecystitis were included in the study. Histopathological diagnosis of gallbladder lesions, age & sex distribution in different gallbladder pathology, association with gall stones, Pathological pT staging of malignant cases and CK7 & CK20 immunohistochemical findings in malignant cases were observed in this study. Results: A total 340 cases of gallbladder specimens were examined histopathologically and 12 cases of gallbladder carcinoma were diagnosed. The most common histopathological diagnosis was chronic cholecystitis (79.4%) followed by chronic cholecystitis with cholesterolosis (7.6%) and adenocarcinoma (3.5%). The most common age group for gallbladder lesions was 4th decade (26.2%). Age varies from 09 – 85 years with a mean age of 39.4 years. Overall females (83%) are more commonly affected than males (17%) with male: female ratio is 1:4.96. Gallstones were present in 89.1% among total cases, 83.3% in malignant cases. Incidentally detected gallbladder carcinoma was 1.17% and most common histopathological type was adenocarcinoma NOS with Pathological pT staging was pT1 & pT2 only i.e. early stage. CK7 positivity was found in 91.6% cases and CK20 was positive in 16.7% cases. Both CK7 & CK20 was positive in 16.7% and both CK7 & CK20 was negative in one case (8.33%). Conclusions: Although the most common gall bladder histopathology diagnosis is chronic cholecystitis, the possibility of any incidental malignancy needs to be ruled out by mandatory routine histopathological examination of all cholecystectomy specimens.

Lymphoepithelial cyst mimicking malignant pancreatic signs: a case report

BackgroundA lymphoepithelial cyst of the pancreas is a rare benign lesion that is difficult to diagnose preoperatively and challenging in distinguishing from potentially malignant cystic pancreatic neoplasms. A diagnostic step-up approach is recommended to clarify the lesion’s dignity and specify a treatment plan.Case presentationHere, we describe a case of a 51-year-old male European with a lymphoepithelial cyst of the pancreas mimicking malignant features in a mid-age male patient with abdominal pain and unintended weight loss.ConclusionPatients with indeterminate cystic pancreatic lesions should be examined by a multidisciplinary diagnostic team in a step-up approach to clarify the lesion’s entity. In the case of incidentally found lymphoepithelial cysts of the pancreas, a watchful waiting strategy might be clinically reasonable if the diagnosis is proven.

Benign peripheral nerve sheath tumors: an interdisciplinary diagnostic and therapeutic challenge

A benign peripheral nerve sheath tumor (bPNST) is a rare lesion associated with peripheral nerval structures. Symptoms may be heterogeneous, complicating diagnosis finding. Additionally, management concepts of bPNST may vary. In some cases, initial misdiagnosis leads to mistreatment resulting in severe functional deficits and chronic pain syndromes. Therefore, we analyzed patients treated for bPNST in our specialized institution with a primary focus on prior misdiagnosis and possible mistreatment. Patients with bPNSTs (schwannomas, neurofibromas, hybrid nerve sheath tumors, and perineuriomas) treated at the Neurosurgical Department between January 1, 2015, and July 31, 2021, were included. Assessment of demographics, tumor entity, tumor location, symptoms, the interval between the onset of symptoms and surgery, involved medical specialties, and outpatients’ treatment, with particular focus on initial misdiagnosis and inappropriate medical treatment, was performed. Eighty-five patients were included in the final analysis with schwannoma being the most prevalent histopathological diagnosis (schwannoma (75.3%, n=64), neurofibroma (12.9%, n=11), hybrid nerve sheath tumor (5.9%, n=5), and perineurioma (5.9%, n=5)). An incorrect primary diagnosis was detected in 44.7% (n=38), leading to suboptimal or insufficient treatment in these cases. Of those, 28.9% (n=11/38) were treated suboptimal, while 18.5% (n=7/38) underwent unnecessary invasive diagnostics. Inappropriate surgery based on prior misdiagnosis, which led to severe neurological deficits in all these cases, was reported in 26.3% (n=10/38). For the first time, our data shows the quantity and impact of incorrect initial diagnosis in bPNST causing a delay in causative treatment or resulting in unnecessary or potentially harmful treatment.

Contribution of Medical Imaging in the Diagnosis of Epidermoid Cyst of the Anterior Fontanel in an Child: A Case at the “Mother-Child" University Hospital Center (Chu) Bamako Luxembourg

This study aims to identify the epidemiological, clinical, radiological, surgical and histological characteristics of epidermoid cysts. The epidermoid cyst of the anterior fontanel is a very rare congenital lesion, less frequent than the dermoid cyst. We report a case of a four-month-old infant who consulted for a mass located at the level of the anterior fontanel. This lesion presented at birth as a small, soft mass covered with normal-looking scalp that gradually enlarged. Computed tomography showed the characteristics of a slightly heterogeneous cystic lesion limited by the superior sagittal sinus below, without intracranial extension. The surgical intervention allowed its ablation in one piece without adhesion. Histology confirmed the diagnosis. The evolution was satisfactory.

Congenital Cyst of Pancreas in a Newborn: A Rare Presentation

Pancreatic cysts are rare lesions in newborns. Prenatal diagnosis of true congenital pancreatic cyst is rare and many times cystic lesion on prenatal scans confused with mesenteric cyst, ovarian cyst, and left renal cyst. Here we report a newborn presented with antenatally detected upper abdominal cystic lesion. The cystic mass was located in the left upper side of the abdomen, and total cystectomy was performed without any intra or post-operative complication. Histopathological examination demonstrated presence of pancreatic tissues in the wall of cyst with foci of inflammation and cystically dilated ducts, lined by flattened epithelium. Features suggestive of congenital true pancreatic cyst with pancreatic fluid as its predominant content.

Role of myofibroblasts in oral plasma cell granuloma: Immunohistochemical evaluation of α-SMA and ALK in a retrospective study of 30 cases

IntroductionOral plasma cell granuloma (OPCG) is a rare reactive lesion with generally benign yet occasionally aggressive behavior. Myofibroblasts are important in many physiologic, and pathologic conditions. The role of myofibroblasts in the clinical behavior of OPCG was assessed as well as its usefulness in differentiating this lesion from the inflammatory myofibroblastic tumor mimicking plasma cell granuloma. Material and MethodsThis retrospective study included 30 paraffin blocks of OPCG. Immunohistochemical evaluation of alpha-smooth muscle actin (α-SMA) and Anaplastic lymphoma kinase (ALK) antibodies was performed. The mean area of positive expression was calculated and scored semiquantitatively with clinicopathologic correlations. ResultsMost of the cases were clinically non-aggressive. Alveolar bone resorption was observed in nine cases, two of them showed severe resorption and stromal fibrosis. Negative α-SMA was observed in 70% of cases showing a predominance of plasma cells in the stroma. All cases of stromal fibrosis revealed positive α-SMA of a weak percentage. A statistically significant difference was observed between α-SMA expression and the clinicopathologic variables. Negative ALK expression was noted in all cases. DiscussionMyofibroblasts were infrequently found in OPCG. Remarkably, the aggressive behavior in cases with intense fibrosis was related to the existence of myofibroblasts even of non-neoplastic nature and minimal amount. The number of myofibroblasts and their nature assessed via α-SMA and ALK immunohistochemical expression respectively might be valuable in predicting the biological behavior of OPCG and may hold diagnostic significance in challenging OPCG cases that might mimic inflammatory myofibroblastic tumor.

Do More with Less? Lobectomy vs. Segmentectomy for Patients with Congenital Pulmonary Malformations.

Congenital Pulmonary Malformations (CPMs) are rare benign lesions potentially causing infective complications and/or malignant transformation, requiring surgery even when asymptomatic. CPMs are rare in adulthood but potentially detected at any age. There is not a consensus on the correct extent of resection in both adults and paediatrics. This retrospective multicentric study aims to identify the appropriate surgical resection to prevent the recurrence of the related respiratory symptoms. Between 2010 and 2020, a total of 96 patients (adults and pediatrics) underwent surgery for CPMs in 4 centers. A 2:1 propensity score matching (considering sex and lesion side) was performed, identifying 2 groups: 50 patients underwent lobectomy (group A) and 25 sub-lobar resections (group B). Clinical and histopathological characteristics, early and late complications, and symptom recurrence were retrospectively analyzed and compared between the two groups by univariate and multivariate analysis. Patients who underwent lobectomy had a statistically significant lower rate of recurrence (4% vs. 24% of group B, p = 0.014) and a lower rate of intraoperative complications (p = 0.014). Logistic regression identified sub-lobar resection (p = 0.040), intra- and post-operative complications (p = 0.105 and 0.022),and associated developed neoplasm (p = 0.062) as possible risk factors for symptom recurrence after surgery. Pulmonary lobectomy seems to be the most effective surgical treatment for CPMs, guaranteeing the stable remission of symptoms and a lower rate of intra- and postoperative complications. To our knowledge, this is one of the largest studies comparing lobectomy and sub-lobar resections in patients affected by CPMs, considering the low incidence worldwide.

WA-ResUNet: A Focused Tail Class MRI Medical Image Segmentation Algorithm.

Medical image segmentation can effectively identify lesions in medicine, but some small and rare lesions cannot be well identified. Existing studies do not take into account the uncertainty of the occurrence of diseased tissue, and the problem of long-tailed distribution of medical data. Meanwhile, the grayscale image obtained from Magnetic Resonance Imaging (MRI) detection has problems, such as the features being difficult to extract and invalid features being difficult to distinguish. In order to solve these problems, we propose a new weighted attention ResUNet (WA-ResUNet) and a class weight formula based on the number of images contained in the class, which improves the performance of the model in the low-frequency class and the overall effect of the model by improving the degree of attention paid to the valid features and invalid ones and rebalancing the learning efficiency among the classes. We evaluated our method on an uterine MRI dataset and compared it with the ResUNet. WA-ResUNet increased Intersection over Union (IoU) in the low-frequency class (Nabothian cysts) by 21.87%, and the overall mIoU increased by more than 6.5%.

Anterior inferior cerebellar artery (AICA) aneurysms: a radiological study of 15 consecutive patients.

The aneurysms of the anterior inferior cerebellar artery (AICA) are rare lesions of the posterior circulation and to treat them is challenging. We aim to present anatomical and morphological characteristics of AICA aneurysms in a series of 15 patients. The DSA and CT angiography images of AICA aneurysms in 15 consecutive patients were analyzed retrospectively. Different anatomical characteristics were quantified, including morphology, location, width, neck width, length, bottleneck factor, and aspect ratio. Eighty percent of the patients were females. The age was 52.4 ± 9.6 (mean ± SD) years. 11 patients were smokers. Ten patients had a saccular aneurysm and five patients had a fusiform aneurysm. Aneurysm in 10 patients were located in the proximal segment, in three patients in the meatal segment, and in two patients in the distal segment. Ten out of 15 patients presented with a ruptured aneurysm. The size of AICA aneurysms was 14.8 ± 18.9 mm (mean ± SD). The aspect ratio was 0.92 ± 0.47 (mean ± SD) and bottleneck factor was 1.66 ± 1.65 (mean ± SD). AICA aneurysms are rare lesions of posterior circulation predominantly found in females, present predominantly with subarachnoid hemorrhage, and are mostly large in size.

Open surgical ligation of a thoracic spinal epidural arteriovenous fistula causing thoracic myelopathy: illustrative case.

Spinal epidural arteriovenous fistulas (eAVFs) are rare spinal vascular malformations characterized by an abnormal connection from the paraspinal and paravertebral system to the epidural venous plexus. This contrasts with the more frequently seen spinal dural AVF, where the fistula is entirely intradural. Although endovascular repair is commonly performed for spinal eAVF, few cases require open surgical ligation. The authors present a case of a 74-year-old male with progressive thoracic myelopathy secondary to a spinal eAVF. Thoracic magnetic resonance imaging (MRI) showed intramedullary T2 signal hyperintensity from T8 to T12. Spinal angiography revealed a primary arterial supply from the right T11 segmental artery and minor supply from the left T11 branches with drainage into the ventral epidural space. The patient underwent T11-12 laminectomy and complete right T11-12 facetectomy for ligation of the fistula with T11-L1 fusion. A postoperative spinal angiogram showed resolution of the fistula. Postoperatively, the patient's myelopathy improved, and MRI showed a decrease in T2 cord intensity. Spinal eAVFs are rare lesions that differ from the more commonly seen intradural dural AVF in that the abnormal connection is in the epidural space, and they are often associated with a dilated epidural venous pouch. Treatment involves endovascular, open surgical, or combined approaches.

Split cornea transplantation in anterior lamellar keratoplasty for limbal dermoid surgery: a case report

Limbal dermoid is a rare congenital lesion that can impair vision and raise aesthetic concerns. Surgery is frequently required to reduce discomfort and enhance visual outcomes. A 20-year-old woman presented with a limbal dermoid measuring 4.5 mm in diameter and half the depth of the stroma. Excision was performed with anterior lamellar keratoplasty (ALK) using a post-Descemet's membrane endothelial keratoplasty graft, which resulted in signs of graft failure. Re-surgery was then performed with post-Descemet's stripping endothelial keratoplasty graft. It yielded a clear graft with good visual acuity. The first corneal graft utilized 95% of the graft thickness to cover 55% of the defect, leading to poor host-donor apposition. The second graft employed 55–65% to cover the same portion of the defect. The proportional thickness of the graft is crucial for a successful ALK. Split cornea transplantation produces respectable results; however, the corneal thickness must be carefully considered.

Primary Malignant Mucosal Melanoma of the Esophagus. A Case Report

Primary malignant melanoma isa rare lesion, that accounts for only 0.1 % of primary esophageal malignant neoplasms. The tumor is polypoid, pedunculated and sometimes ulcerated. Symptoms are similar to those of squamous cell carcinoma and the preoperative differential diagnosis is important. Surgical resection is the treatment of choice. In tracavitary radiotherapy may be a useful form of adjuvant therapy in selected patients. Here we record the case of a 67 years old man with a primary malignant melanama of the esophagus. He underwent an esophagectomy, and is stili alive 5 months aftnr lhe procedure.

Dumble cystic lymphangioma as an underlying cause of vague abdominal complaints in a 2-year-old girl: case report.

The authors report a mesenteric macrocytic LM in a 2-year-old girl complaining of vague abdominal discomfort and persistent vomiting in which ultrasonography revealed a cystic masse with seromucous components. She then underwent exploratory laparotomy. The operation and the follow-up duration were uneventful. LMs are rare benign lesions of vascular origin with lymphatic differentiation, according to the latest International Society for the Study of Vascular Anomalies (ISSVA 2018). Under light microscopy, these malformations are characterized by their thin-walled endothelium and lymphatic tissue.These mobile lesions are incidentally found or appear with intestinal obstruction or acute abdomen scenarios. Although benign, the LMs have the potential for invasion and recurrence. Thus, the examiner physician must keep such intra-abdominal lesions in mind.

Relationship Between Pericallosal Lipoma and Neuropsychiatric Symptoms: A Case Report.

Intracranial lipomas are extremely rare fat-containing lesions that occur due to the abnormal differentiation of embryonic meninges. Interhemispheric lipomas that are closely related to the corpus callosum are also referred to as pericallosal lipomas and are the most common subtype. Pericallosal lipomas are associated with varying degrees of dysgenesis of the corpus callosum and therefore have a broad clinical presentation. Herein, we describe a case of a 15-year-old man who presented with a history of developmental delay and psychiatric symptoms and was incidentally found to have a pericallosal lipoma on magnetic resonance imaging, prompting clinical correlation.