Rare Tumor Type Research Articles

The presenting symptoms of patients with appendiceal malignant tumors.

824 Background: Timely detection of appendiceal malignant tumors is a clinical priority because of the propensity for this malignancy to metastasize to the peritoneal cavity. Up to one in every 2 patients with this rare tumor type will present with distant metastatic disease, owing to there being no standardized screening tests for early detection of primary appendiceal cancers. Case reports have pointed to broad/non-specific symptoms of patients diagnosed with appendiceal malignant tumors, yet information is needed from large cohorts to support prompt/accurate clinical diagnoses. Methods: We analyzed data from patients with a pathologically-confirmed first primary appendiceal malignant tumor (AC) who prospectively enrolled in the nation-wide Genetics of Appendix Cancer [GAP] clinical cohort study (Clinicaltrials.gov, NCT05734430) between November 2022 and May 2024. The primary outcome was presenting symptoms that led to AC diagnosis. Symptom effects and interactions with diagnosis age/year, sex, body mass index (BMI), and tumor histology, were quantified with negative binomial regression models and presented as incidence rate ratios (IRRs) and 95% confidence intervals. Results: Of the 352 patients included in our analyses (median [IQR] age, 51.0 [42-59] yr), 77.6% were female and 96.6% had an adenocarcinoma histology. Seventy-seven percent of patients (n=270) reported one or more presenting symptoms, of whom 55.2% (n=149) experienced these symptoms for 3+ months prior to diagnosis. On average, patients reported 3 symptoms (mean: 2.9, SD 3.0). The most prevalent symptoms among males and females were abdominal pain (57.1%), bloating/distension (32.1%), pelvic pain (18.5%), and abdominal/pelvic mass (18.2%). Overall, patients with early-onset AC [age<50] more commonly presented with symptoms versus cases with late-onset AC (82.9% vs 71.7%, p =0.01). This finding persisted in adjusted models—the number of symptoms was highest among younger patients, rapidly decreased and plateaued around age 50 (IRR 0.97, 95%CI 0.95-0.99, p =0.002), and slowly increased again with older age (IRR 1.03, 95%CI 1.00-1.05, p =0.037). Patient sex was also significantly associated with symptom number, as males had a lower rate of symptoms versus females (IRR 0.63, 95%CI 0.48-0.83, p =0.001). In contrast, histology (IRR 1.03, 95%CI 0.53-2.02), diagnosis year (IRR 1.01, 95%CI 0.99-1.04, p =0.35) and BMI (IRR 1.01, 95%CI 0.99-1.02) were not associated with symptom number in adjusted models. Conclusions: In a large nation-wide cohort, three of every 4 patients were symptomatic prior to primary AC diagnosis. Compared to the rapid time course of acute appendicitis, over 40% of this population presented with symptoms for 3+ months prior to AC diagnosis. The higher symptom burden among young patients and females supports the need for clinical providers to keep occult appendiceal tumors in the differential diagnosis of patients presenting in this manner.

Birth cohort effects in appendiceal adenocarcinoma incidence across the United States.

90 Background: Appendiceal adenocarcinoma incidence rates are increasing across all age groups, sexes and histological subtypes in the United States. Birth cohort patterns of appendiceal adenocarcinomas can provide us with new, etiologic clues into these rising rates but have not been examined for this rare malignant tumor type. We estimated appendiceal adenocarcinoma incidence rates across birth cohorts in the United States. Methods: Using the National Cancer Institute’s Surveillance, Epidemiology, and End Results (SEER) Program data from eight population-based cancer registries, we identified a total of 4,858 persons aged 20+ years when diagnosed with a pathologically-confirmed primary appendiceal adenocarcinoma (non-mucinous, mucinous, goblet cell, signet ring cell carcinoma) between 1975 and 2019. Birth cohorts (1900-1904 to 1990-1994) were created using five-year age groups and time periods. The ratio of age-specific incidence rates was estimated in each birth cohort relative to the 1945-1949 birth cohort and reported as incidence rate ratios (IRRs) with 95% confidence intervals (CI). Results: Compared to persons born in 1945-1949, appendiceal adenocarcinoma incidence rates more than tripled among persons born in 1980-1984 (IRR 3.41, 95%CI 2.54-4.56) and quadrupled among persons born in 1985-1989 (IRR 4.62, 95%CI 3.12-6.82). For all tumor histological types, age-specific appendiceal adenocarcinoma incidence rates increased across successive birth cohorts after 1945-1949—although to varying degrees reported across histological types (e.g., 1980-1984: mucinous adenocarcinoma: IRR 2.71, 95% CI 1.73-4.26; non-mucinous adenocarcinoma: IRR 2.60, 95% CI 1.46-4.63; goblet cell adenocarcinoma: IRR 4.95, 95% CI 2.77-8.85). Conclusions: There are strong, yet distinct birth cohort effects for appendiceal adenocarcinomas across histological subtypes that remain unexplained. These patterns signal that recent exposure changes may be influencing this increasing disease risk for Generation X and Millennials now entering mid-adulthood. With the trend toward more non-operative management of appendicitis, another significant consideration for providers is to keep occult appendiceal tumors in the differential diagnosis of patients who present in this way. The current absence of appendiceal cancer prevention and screening modalities emphasizes the importance of efforts to support earlier detection in a rare malignancy where clinical trials have been historically very limited. Moreover, as similar trends have been reported in other gastrointestinal cancers, this is also suggestive of potential shared exposures contributing to this rising cancer burden across generations.

Rare malignant ovarian tumors: a review.

There are many histologic types of gynecologic malignancies. I reviewed three rare ovarian tumor types that have poor prognoses. Ovarian mesonephric-like adenocarcinoma (MLA) is a newly described histological type known for its aggressive behavior. It is thought to arise from mesonephric duct remnants of the female genital tract and is typically associated with endometriosis. Although MLA has some similarities to endometrioid carcinoma, they have different prognoses. Recurrence of MLA is common, even in early stage cases, and distant metastases, especially in the lungs, are often seen. MLA is characterized by positive immunohistochemical-staining for TTF-1, GATA3, PAX2, and CD10, and negative staining for estrogen and progesterone receptors. Data on treatment for MLA are scarce, and further studies are needed. Adult granulosa cell tumors, the most common type of malignant ovarian sex cord-stromal tumors, have an indolent growth pattern. Chemotherapy, hormone therapy, and radiotherapy have all shown some efficacy. However, debulking surgery remains the most important treatment because tumor disruption or remnants are risk factors for recurrence. Late recurrence is also characteristic of this tumor. Malignant transformations of mature teratoma are suspected when the patient is relatively old and the tumor is large. Squamous cell carcinoma is the most common somatic malignancy. Treatment must be tailored to the transformed histology. Chemotherapy and radiation have shown some efficacy; however, the prognosis is extremely poor in advanced cases. Because these three types of ovarian tumors are rare, research on possible treatments has been difficult, but recent significant advances in drug therapy are expected to lead to the development of effective treatments.

Transcription Factor Fingerprint Provides Clues for Brain Tumor Cell of Origin.

Mouse models that faithfully represent the biology of human brain tumors are critical tools for unraveling the underlying tumor biology and screening for potential precision therapies. This is especially true of rare tumor types, many of which have correspondingly few xenograft or cell lines available. Although our understanding of the specific biological pathways driving cancer has improved significantly, identifying the appropriate progenitor populations to drive oncogenic processes represents a significant barrier to efficient mouse model production. In this issue of Cancer Research, Jessa and colleagues developed an innovative transcription factor fingerprinting method to map the cellular origin of central nervous system neuroblastoma, FOXR2-activated to medial ganglionic eminence-derived interneurons, which could then be efficiently targeted in the developing mouse brain using in utero electroporation. This approach serves as a blueprint for investigating other rare pediatric brain tumors, potentially accelerating progress toward the development of mouse models and identification of effective therapies. See related article by Jessa et al., p. 231.

The Relevance of the Virchow Node and Virchow Triad in Renal Cancer Diagnosis.

Background: The purpose of this article is to overview the clinical significance of left supraclavicular adenopathy and review the etiology of inferior vena cava (IVC) thrombosis, starting from a presentation of a rare case of renal cell carcinoma (RCCs) with Xp11.2 translocation involving TFE3 gene fusion. This article also aims to review the literature to understand the characteristics of this rare type of renal tumor. Renal cell carcinoma (RCC) associated with Xp11.2 translocation/gene fusion TFE3 is a rare subtype of kidney cancer that was classified in 2016 as belonging to the family of renal carcinomas with MiT gene translocation (microphthalmia-associated transcription factor). The prognosis for these kidney cancers is poorer compared to other types. Methods: We present a case of a 66-year-old man with Virchow-Troisier adenopathy during physical examination, which raises the suspicion of infra-diaphragmatic tumor. The echocardiography highlighted a heterogeneous mass in the right cardiac cavities, and the abdominal ultrasound exam revealed a solid mass at the upper pole of the left kidney. Results: Following computed tomography, magnetic resonance imaging, PET-CT, and histopathological and immunohistochemical examinations, the patient was diagnosed with renal carcinoma with Xp11.2 translocation and TFE3 gene fusion. Conclusions: IVC thrombosis is often associated with neoplastic disease due to the procoagulant state of these patients, the most common malignancies related to IVC thrombosis being represented by RCCs (38%), genitourinary cancers (25%), bronchus and lung cancers, retroperitoneal leiomyosarcoma, and adrenal cortical carcinoma. Imaging methods play a crucial role in differential diagnosis, allowing for the localization of the primary tumor and assessment of its characteristics.

Central Nervous System Tumor-Embryonal Tumors Type With Neuroendocrine Differentiation.

The central nervous system (CNS) tumor with embryonal tumors type is a rare type of CNS tumor with lack of unifying genetic alterations or diagnostic markers. The CNS tumor-embryonal tumors (CETs) have limited therapeutic options with high probability of adverse events associated with conventional treatment. Identification of somatostatin receptor expression and/or prostate-specific membrane antigen expression in CET patients by using PET/CT imaging may be helpful for deciding therapeutic approaches in these patients as theranostics. We present a 56-year-old woman who complained of headache, diminution of vision, and diagnosed CET and demonstrated high SSTR expression on PET/CT imaging, indicating peptide receptor radionuclide therapy could be effective therapeutic option in this case.

M&M: an RNA-seq based pan-cancer classifier for paediatric tumours.

With many rare tumour types, acquiring the correct diagnosis is a challenging but crucial process in paediatric oncology. Historically, this is done based on histology and morphology of the disease. However, advances in genome wide profiling techniques such as RNA sequencing now allow the development of molecular classification tools. Here, we present M&M, a pan-paediatric cancer ensemble-based machine learning algorithm tailored towards inclusion of rare tumour types. The RNA-seq based algorithm can classify 52 different tumour types (precision ∼99%, recall ∼80%), plus the underlying 96 tumour subtypes (precision ∼96%, recall ∼70%). For low-confidence classifications, a comparable precision is achieved when including the three highest-scoring labels. We then validated M&M on an internal dataset (precision 99%, recall 76%) and an external dataset from the KidsFirst initiative (precision 98%, recall 77%). Finally, we show that M&M has similar performance as existing disease or domain specific classification algorithms based on RNA sequencing or methylation data. M&M's pan-cancer setup allows for easy clinical implementation, requiring only one classifier for all incoming diagnostic samples, including samples from different tumour stages and treatment statuses. Simultaneously, its performance is comparable to existing tumour- and tissue-specific classifiers. The introduction of an extensive pan-cancer classifier in diagnostics has the potential to increase diagnostic accuracy for many paediatric cancer cases, thereby contributing towards optimal patient survival and quality of life. Financial support was provided by the Foundation Children Cancer Free (KiKa core funding) and Adessium Foundation.

Testicular sex cord-stromal tumors in mice with constitutive activation of PI3K and loss of Pten.

Testicular tumors are the most common malignancy of young men and tumors affecting the testis are caused by somatic mutations in germ or germ-like cells. The PI3K pathway is constitutively activated in about one third of testicular cancers. To investigate the role of the PI3K pathway in transforming stem-like cells in the testis, we investigated tumors derived from mice with post-natal, constitutive activation of PI3K signaling and homozygous deletion of tumor suppressor Pten, targeted to nestin expressing cells. Mice developed aggressive tumors, exhibiting heterogeneous histopathology and hemorrhaging. The tumors resemble the rare testis tumor type, testicular sex cord-stromal Leydig cell tumors. Single cell resolution spatial tissue analysis demonstrated that T-cells are the dominant tumor infiltrating immune cell type, with very few infiltrating macrophages observed in the tumor tissue, with CD8+ T-cells predominating. Further analysis showed that immune cells preferentially localize to or accumulate within stromal regions.

NAB2-STAT6 drives an EGR1-dependent neuroendocrine program in Solitary Fibrous Tumors.

The pathogenesis of many rare tumor types is poorly understood, preventing the design of effective treatments. Solitary fibrous tumors (SFTs) are neoplasms of mesenchymal origin that affect 1/1,000,000 individuals every year and are clinically assimilated to soft tissue sarcomas. SFTs can arise throughout the body and are usually managed surgically. However, 30-40% of SFTs will relapse local-regionally or metastasize. There are no systemic therapies with durable activity for malignant SFTs to date. The molecular hallmark of SFTs is a gene fusion between the NAB2 and STAT6 loci on chromosome 12, resulting in a chimeric protein of poorly characterized function called NAB2-STAT6. We use primary samples and an inducible cell model to discover that NAB2-STAT6 operates as a transcriptional coactivator for a specific set of enhancers and promoters that are normally targeted by the EGR1 transcription factor. In physiological conditions, NAB2 is primarily localized to the cytoplasm and only a small nuclear fraction is available to operate as a co-activator of EGR1 targets. NAB2-STAT6 redirects NAB1, NAB2, and additional EGR1 to the nucleus and bolster the expression of neuronal EGR1 targets. The STAT6 moiety of the fusion protein is a major driver of its nuclear localization and further contributes to NAB2's co-activating abilities. In primary tumors, NAB2-STAT6 activates a neuroendocrine gene signature that sets it apart from most sarcomas. These discoveries provide new insight into the pathogenesis of SFTs and reveal new targets with therapeutic potential.

Penile Cancer, An Uncommon But Threatening Form Of Cancer: A Case Report

Penile cancer is rare type of tumor mostly seen in men over 50. Most often, patients fail to recognize their symptoms and decide to suppress their pain out of fear of being judged by others. Patients continue to be reluctant to discuss genital issues with doctors and to seek therapy early in the course of the disease. Patient education is crucial for an early cancer diagnosis because a delay in the diagnosis can raise worldwide mortality rate. The following case study describes a 77-year-old man with penile cancer who visited the hospital at a late stage of the disease, which results in delaying the initiation of treatment. In our case report, the patient received prompt treatment after receiving a diagnosis of terminal penile cancer. The case report presented here is crucial for helping medical professionals in the treatment of advanced cancer patients.

GLI1-altered mesenchymal tumor of tongue: a case report and literature review.

GLI1-altered mesenchymal tumors are a relatively rare type of mesenchymal tumor that is common in the head and neck. It is a newly added tumor type in the World Health Organization Tumor Classification of Head and Neck (5th edition). This article reports a case ofGLI1-alteredmesenchymal tumor occurring at the left tongue and reviews the relevant literature to summarize the pathological morphological characteristics, immunophenotype, molecular changes, clinical manifestations, and prognosis of the disease.

Clinical characteristics and prognostic analysis of patients with SMARCA4-deficient lung cancer

Background SMARCA4-deficient NSCLC is a rare type of tumor, accounting for approximately 10% of all NSCLC. It exhibits a weak response to conventional chemotherapy and has a poor prognosis, and lacks alterations in EGFR (epidermal growth factor receptor), ALK (anaplastic lymphoma kinase), and ROS1 (ROS proto-oncogene 1) genes Therefore, the mechanisms of SMARCA4 in NSCLC development urgently need to be explored to identify novel biomarkers and precise therapeutic strategies for this subtype. Objective The aim of this study was to understand the clinical characteristics of this special type of tumor and its response to different treatments. Methods We collected clinical data from 42 patients with SMARCA4-deficient NSCLC from July 2022 to January 2024, and analyzed their clinical features and survival state. Results The study included a total of 42 patients diagnosed with NSCLC and harboring SMARCA4 mutation. The majority of these patients were male with a median age of 67 years. Most patients presented at stage IV upon diagnosis with highly aggressive tumors characterized by high Ki-67 proliferation index values resulting in poor overall prognosis. Genetic testing revealed TP53 gene mutations to be most prevalent (21%), followed by KRAS mutations (13%). Patients receiving immunotherapy exhibited significantly longer median overall survival compared to those treated solely with chemotherapy. Targeted drug therapy demonstrated favorable effects in some patients. Conclusion NSCLC patients harboring SMARCA4 deficiency exhibit poor overall survival rates with a median overall survival time of 5.4 months. Immunotherapy may provide benefits for NSCLC patients with SMARCA4 deficiency.

Solitary Fibrous Tumor of the Larynx: A Case Report and Brief Literature Review.

Solitary fibrous tumors (SFTs) are a rare type of soft tissue tumor first identified as arising from pleura and usually arising in the thoracic cavity. The incidence of SFTs arising in the head and neck region is much lower, accounting for about 7% of SFT cases. Involvement of the larynx specifically is exceedingly rare and can have inconspicuous presentations, making them challenging to diagnose. This case report represents a patient with a history of urothelial cancer and obstructive sleep apnea who was ultimately found to have a fibrous tumor of the larynx, which was confirmed by histopathology and immunohistochemistry and treated with transoral microsurgical resection. This case report aims to shed light on an infrequently documented location of a solitary laryngeal fibrous tumor and a unique clinical presentation of this rare pathology and its successful surgical management.

A case of ovarian mesothelioma with VHL mutation diagnosed by immunohistochemistry and literature review.

The malignant mesothelioma mainly develops in the pleura and peritoneum, while primary ovarian mesothelioma is very rare. Here, we report the first case of primary ovarian mesothelioma (clear cell variant) with VHL mutations in the world based on the results of histomorphology, immunohistochemistry, and genetic testing. This is an extremely rare type of tumor that has not been reported so far. Through the literature search, we reviewed primary ovarian mesothelioma, focusing on its differential diagnosis and molecular genetics. The purpose of this paper is to deepen the flexible selection and application of immunohistochemical markers in mesothelioma, so as to reduce missed diagnosis and misdiagnosis.

Primary Large-Cell Neuroendocrine Carcinoma of the Breast.

Breast neuroendocrine carcinoma (NECB) is a rare type of breast tumor. Large-cell neuroendocrine carcinomas of the breast (LCNECB) are a special and rare histological subtype of NECB. Here, we present a case of a 59-year-old woman who was diagnosed with an LCNECB. A mass in the upper outer quadrant of the right breast was revealed via imaging. A histological examination showed the tumor cells were composed of clusters of large cells with obvious atypia that were polygonal or irregularly shaped. The patient underwent a right-breast-conserving radical surgery and sentinel lymph node biopsy (SLB). A histopathological examination revealed that the tumor of the right breast was 2.5 × 2 cm in size with vascular invasion, and the sentinel lymph node was negative. The immunohistochemical results showed that the tumor cells were diffuse and positive for chromogranin A (CgA), synaptophysin (Syn), and INSM1. The patient successfully completed chemotherapy and radiotherapy and is currently undergoing endocrine therapy.

A Case Series of a Rare Parotid Gland Oncocytic Mucoepidermoid Carcinoma

Abstract Introduction/Objective We analyzed two cases of oncocytic mucoepidermoid carcinoma (OMEC) of the parotid gland which highlight the diagnostic challenges of oncocytic salivary gland neoplasms. OMEC’s are a rare type of salivary gland tumor commonly arising from the parotid gland that can easily be mistaken as benign. Proper pathologic diagnosis of these masses is critical, as it guides therapeutic intervention and has prognostic significance. Methods/Case Report In this case series, two patients were analyzed retrospectively for unilateral parotid masses. Results (if a Case Study enter NA) In a 67-year-old female, an MRI and biopsy were performed. Only a differential diagnosis could be provided, which favored oncocytoma or oncocytic carcinoma. Due to this uncertainty, a complete excision of the mass was performed. Considering the cytomorphology, immunohistochemistry (CK5/6 and P63 in oncocytes), and mucicarmine special stain highlighting scattered mucocytes, the patient was diagnosed with a low- grade OMEC. In our second case, an 80-year-old female, FNA of a posterior left ear mass 1 year prior revealed a low- grade oncocytic proliferation. With the presence of a left parotid mass one year later, additional imaging was performed and showed increased T2 hyperintensity on MRI, which caused concern for the clinicians. A superficial limited parotidectomy was performed and a differential of oncocytoma versus oncocytic variant of mucoepidermoid carcinoma was rendered. Further tumor characterization with fluorescence in situ hybridization (FISH) demonstrated a MAML2 translocation which guided diagnosis of OMEC. Conclusion With approximately 30% of all malignant salivary gland tumors being constituted by mucoepidermoid carcinoma, the ability to accurately diagnose even this rare subtype, oncocytic mucoepidermoid carcinoma, is of significant importance and relevance to pathologists in many practice settings. Herein we demonstrate the utility of H&E morphology, immunohistochemistry, and MAML2 FISH in diagnosing OMEC in the setting of oncocytic salivary gland lesions. Future avenues, including tumor molecular profiling, will aid in elucidating clinicopathologic characteristics of this entity.

Papillary Craniopharyngioma: an integrative and comprehensive review.

Papillary craniopharyngioma (PCP) is a rare type of tumor, comprising ∼20% of all craniopharyngioma (CP) cases. It is now recognized as a separate pathological entity from the adamantinomatous type. PCPs are benign tumors, classified as WHO grade 1, characterized by non-keratinizing squamous epithelium. They typically grow as solid and round papillomatous masses or as unilocular cysts with a cauliflower-like excrescence. PCPs primarily occur in adults (95%), with increased frequency in males (60%) and predominantly affect the hypothalamus. Over 80% of these tumors are located in the third ventricle, expanding either above an anatomically intact infundibulum (strictly third ventricle tumors) or within the infundibulo-tuberal region of the third ventricle floor. Clinical manifestations commonly include visual deficits and a wide range of psychiatric disturbances (45% of patients), such as memory deficits and odd behavior. MRI can identify up to 50% of PCPs by the presence of a basal duct-like recess. Surgical management is challenging, requiring complex approaches to the third ventricle and posing significant risk of hypothalamic injury. The endoscopic endonasal approach allows radical tumor resection and yields more favorable patient outcomes. Of intriguing pathogenesis, over 90% of PCPs harbor the somatic BRAFV600E mutation, which activates the mitogen-activated protein kinase (MAPK/ERK) signaling pathway. A phase 2 clinical trial has demonstrated that PCPs respond well to BRAF/MEK inhibitors. This comprehensive review synthesizes information from a cohort of 560 well-described PCPs and 99 large CP series including PCP cases published from 1856-2023 and represents the most extensive collection of knowledge on PCPs to date.

Extraosseous Ewing's Sarcoma Masquerading as Adolescent Neck Mass-a Case Report and Review of Literature.

Ewing sarcoma (ES) is a rare type of malignant bone tumor that arises from mesenchymal stem cells. It commonly occurs in the diaphysis and diaphyseal-metaphyseal portions of long bones, pelvis, and ribs, although any bone can be affected. A minority of the Ewing sarcoma also arise in soft tissues, and a primary tumor in the neck with metastasis is extremely uncommon. We are reporting the case of a 12-year-old female with a history of fever for 4 months and a neck mass for 3 months. Given the broad range of inflammatory and neoplastic etiologies, an extensive laboratory and imaging workup was conducted. Cervical lymph node biopsy for histopathology showed sheets of round blue cells consistent with the diagnosis of Ewing sarcoma in the neck, while a positive immunohistochemical assays for NKX2.2, and negative assay for PAX-5, TdT markers neurofilament, neuron-specific enolase, and S100 protein ruled out the alternative etiologies such as rhabdomyosarcoma and lymphoma. After surgical excision of tumor, chemoradiotherapy was initiated. Despite the typically benign nature of extraosseous Ewing tumors, they can rarely metastasize in less than 20% of cases, as exemplified by this rare case. Accurate diagnosis requires a combined clinic-radio-immunohistochemical approach, and general practitioners should be aware of this clinical entity in neck masses considering its variable clinical presentation and poor prognosis in certain patient's population.

Peripheral Ameloblastoma: A rare case of soft tissue tumor (Case Study)

A rare case of Peripheral ameloblastoma (PA) is reported. This rare type of tumor, classified as benign, locally invasive odontogenic tumor which histologically resembles an intraosseous ameloblastoma but develops in the soft tissues of the gingiva and mucosa. The prevalence of PA ranging from 2-10% compared to the other types of ameloblastoma. A case of PA in a 56-years-old male with an exophytic painless mass in the gingiva of the anterior mandible provisionally diagnosed as irritation fibroma is reported. Histopathological result of surgical treatment was concluded as acanthomatous peripheral ameloblastoma. Based on this experience clinical manifestation of gingival tumor a careful diagnosis should be taken by included the PA in differential diagnosis, in order to manage an adequate treatment and to ovoid of tumor recurrent.

Retroperitoneal lymphangioma in a tertiary care hospital of North India

Less than 200 cases of retroperitoneal lymphangiomas (RL), a rare type of benign cystic tumour of the lymphatic system that makes about 1% of all lymphangiomas, have been documented to date. Their rarity makes preoperative diagnosis challenging. 95% of lymphangiomas are found in the head, neck, and axilla where they are most frequently found. We are presenting a 30 years old woman, who presented to outpatient department (OPD) of general surgery with symptoms of recurrent left lumbar pain, radiating towards inguinal region for one month. The contrast computed tomography (CT) scan of abdomen and pelvis defined a large thin walled homogenous non enhancing hypodense cystic lesion in left side of abdomen in retroperitoneal location from left lobe of liver till pelvis on left side craniocaudally. The patient was planned for exploratory laparotomy. Midline laparotomy was performed. A cystic lymph-filled tumour was detected in the abdominal cavity adjacent to the bowel loops. Histologically the mass contained variable-sized cystic spaces lined by flattened endothelium consistent with lymphatic vessels, which on immunostaining were positive for CD31 and negative for Pan CK. The patient was discharged satisfactorily. In conclusion, retroperitoneal lymphangioma presents vaguely as abdominal pain or mass and grown to large sizes without causing any significant symptom. Tumour markers for the excised tissue are important for diagnosis. Laparotomy or laparoscopy are the two surgical excision methods used to treat retroperitoneal cystic lymphangioma and it responds well to excision.