Case of NUTM::CIC fusion sarcoma surrounding inflatable penile prosthesis.

A 66 year old male with history of inflatable penile prosthesis (IPP) placement was incidentally diagnosed with a 5 cm inguinal mass abutting the IPP reservoir after prostate MRI performed for an elevated PSA. This was surgically resected en bloc with his ipsilateral testicle and IPP reservoir, with final pathology demonstrating a high-grade round cell NUTM::CIC fusion sarcoma. Management is primarily surgical, though patients with high-risk features may require adjuvant chemoradiation.

Novel PAX3::INO80D Fusion in Biphenotypic Sinonasal Sarcoma in an Adult.

This case report describes a novel gene fusion of PAX3::INO80D in a biphenotypic sinonasal carcinoma in a woman in her 40s.

Response to selpercatinib in a patient with RET fusion-positive pulmonary large-cell neuroendocrine carcinoma: A case report.

Large-cell neuroendocrine carcinoma (LCNEC) is a rare subtype of non-small-cell lung cancer associated with a poor prognosis. LCNEC is genetically heterogeneous, and studies have revealed distinct molecular subtypes of LCNEC, which may have therapeutic implications. Herein, we present a case of a patient with stage IV LCNEC harboring a KIF5B-RET fusion whose disease responded to the selective RET inhibitor selpercatinib both extra- and intra-cranially, highlighting the importance of comprehensive molecular testing in LCNEC for selection of optimal treatment.

Subcutaneous panniculitis-like T cell lymphoma arising in association with chronic lymphocytic leukaemia.

Subcutaneous panniculitis-like T cell lymphoma (SPTCL) is a rare cutaneous T cell malignancy of cytotoxic T cell origin. It is frequently associated with autoimmune diseases. It is known to preferentially involve subcutaneous adipose tissue and histologically resembles lupus panniculitis. The aetiology and risk factors of SPTCL are unclear and there are limited studies available since this entity was initially described in 2001. There are even fewer case reports describing the association between SPTCL and chronic lymphocytic leukemia (CLL). In this article, we present a case of SPTCL arising during treatment for CLL. We conducted an extensive review of literature to delve into the possible risk factors for SPTCL development in association with CLL, including pre-existing haematological malignancies, autoimmune conditions, immunomodulation and immunosuppressive chemotherapy.

Single Institutional Experience on Orbital Inflammatory Pseudotumor: Diagnostic and Management Challenge.

AIMS: Orbital inflammatory pseudotumor is considered a non-neoplastic inflammatory process. The finding of clonality of B or T-cell receptors in cases pathologically diagnosed as orbital inflammatory pseudotumor has unknown clinicopathologic significance. We sought to investigate potential B and T-cell clonality and concomitant diseases in cases pathologically diagnosed as orbital inflammatory pseudotumor. METHODS: Cases diagnosed as orbital inflammatory pseudotumor at our institution were retrospectively analyzed. Hematoxylin and eosinstained slides, immunohistochemically stained slides and polymerase chain reactions on cell block material for the investigation of clonality of B and T-cell receptors were evaluated, to confirm the diagnosis and investigate the prevalence of concomitant diseases. RESULTS: A total of 13 cases showing characteristic histopathologic features of orbital inflammatory pseudotumor were identified. CD138, IgG, and IgG4 showed varying numbers of plasma cells in each case, with 5 cases (5/13, 38%) exhibiting relative increase in the presence of IgG4 plasma cells. However, no cases showed diagnostic findings of IgG4-related disease (IgG4-RD). polymerase chain reactions analysis showed clonal B-cell populations in 2 cases (2/13, 15%). No cases showed anaplastic lymphoma kinase expression by immunohistochemistry. There were no clinical reports of progression to lymphoma or development of systemic IgG4-RD in any of the patients (average follow-up of 300 days), with 38% of patients showing systemic autoimmune conditions. CONCLUSION: A small but significant percentage of typical orbital inflammatory pseudotumor on histology showed B-cell clonality on polymerase chain reactions analysis of B-cell receptors, or features suggestive, but not diagnostic of IgG4-RD. Close follow-up of these patients to identify development of lymphoma, systemic IgG4-RD, or other rheumatologic conditions may be clinically warranted.

Hepatocellular carcinoma with biliary and neuroendocrine differentiation: A case report.

BACKGROUND: Liver tumors with dual differentiations [combined hepatocellular carcinoma (HCC) and cholangiocarcinoma] are common. However, liver tumors that exhibit hepatocellular, biliary, and neuroendocrine differentiation are exceedingly rare, with only three previous case reports in the literature. CASE SUMMARY: A 65-year-old female with a previous history of hepatitis C and a distant history of low grade, well-differentiated rectal neuroendocrine tumor was found to have two liver lesions in segment 4 and segment 7 on imaging. Serum alpha-fetoprotein and chromogranin A were elevated. Biopsy of the larger lesion in segment 4 revealed a high-grade tumor, with morphologic and immunohistochemical features of a neuroendocrine tumor. Given the previous history of rectal neuroendocrine tumor, imaging investigation, serologic markers, and biopsy findings, metastatic neuroendocrine tumor was considered. Subsequent regional resection of these hepatic lesions revealed the segment 4 lesion to be a HCC with additional biliary and neuroendocrine differentiation and the segment 7 lesion to be a cholangiocarcinoma with neuroendocrine differentiation. Follow-up of the patient revealed disease recurrence in the dome of the liver and metastasis in retro-pancreatic lymph nodes. The patient eventually expired due to complications of chemotherapy. CONCLUSION: HCC cases with additional biliary and neuroendocrine differentiation are exceedingly rare, posing a diagnostic challenge for clinicians and pathologists.

Lamotrigine-associated hemophagocytic lymphohistiocytosis.

Hemophagocytic lymphohistiocytosis (HLH) is a rare and life-threatening disorder of excessive immune activation. It is mostly seen in the paediatric population and is rarely observed in adults. HLH can be inherited or acquired and is commonly triggered by activation of the immune system by an underlying viral infection or in immune system deficiency such as malignancy or underlying rheumatological disease. HLH is a difficult entity to diagnose due to the rarity of this disorder, variable clinical presentation and non-specific clinical and laboratory findings. HLH carries a high mortality if left untreated, and therefore prompt diagnosis and initiation of immunosuppressive, immunomodulatory and cytostatic medications are critical to improve survival in affected patients. Here, we present a case of lamotrigine-associated HLH. To our knowledge, only eight other cases of lamotrigine-associated HLH have been reported in adult patients.

Giant Granular Cell Tumor of the Cervical Spinal Cord Resected via Anterior Corpectomy with Reconstruction: Technical Note and Review of Literature.

BACKGROUND: Granular cell tumors (GCT) are rare soft tissue neoplasms with a nerve sheath origin, most often found in female adult populations. When these tumors arise in the central nervous system, they most commonly appear intradurally in the thoracic or lumbar spine. GCT malignancy rates vary and recurrence rates can be relatively high, thereby necessitating complete resection. CASE DESCRIPTION: We present an exceedingly rare case of an intradural, extramedullary GCT originating in the anterior cervical spine of a male pediatric patient who presented with progressive neck pain and gait instability. CONCLUSIONS: The patient underwent an anterior C7 corpectomy for resection of the tumor, followed by stabilization and fusion, and recovered without neurologic deficit. A literature review of spinal GCTs is provided.

Clear cell sarcoma in unusual sites mimicking metastatic melanoma.

BACKGROUND: Clear cell sarcoma is an aggressive rare malignant neoplasm with morphologic and immunohistochemical similarities to malignant melanoma. Both disease entities display melanin pigment and melanocytic markers, making differentiation between the two difficult. Although clear cell sarcoma cases in the literature have mainly involved deep soft tissues of the extremities, trunk or limb girdles, we report here two cases of primary clear cell sarcoma in unusual sites and describe their clinicopathologic findings. CASE SUMMARY: The first case involves a 37-year-old female, who presented with jaw pain and a submandibular mass. The second case involves a 33-year-old male, who presented with back pain and a thoracic spine tumor. Both cases showed tumors with diffuse infiltration of neoplastic cells that were positive for melanocytic markers, and in both cases this finding led to an initial diagnosis of metastatic melanoma. However, further analysis by fluorescence in situ hybridization (commonly known as FISH) showed a rearrangement of the EWS RNA binding protein 1 (EWSR1) gene on chromosome 22q12 in both patients, confirming the diagnosis of clear cell sarcoma. CONCLUSION: Distinction between clear cell sarcoma and malignant melanoma can be made by FISH, particularly in cases of unusual tumor sites.

Clinical Activity of Nivolumab for Human Papilloma Virus-Related Juvenile-Onset Recurrent Respiratory Papillomatosis.

BACKGROUND: Juvenile-onset recurrent respiratory papillomatosis (JO-RRP) is a human papilloma virus-mediated progressive benign neoplasm that affects children and young adults. Primary management consists of regular surgical debulking to maintain airway patency and vocal function. Like condyloma acuminata, JO-RRP is associated with immune dysregulation, and T cells isolated from papillomas express an anergic phenotype. Therefore, we hypothesized that programmed death protein 1 axis inhibition could stabilize tumor growth. MATERIALS AND METHODS: We treated two patients with refractory JO-RRP using nivolumab, with the primary objective of assessing clinical activity. We explored baseline papilloma features using immunohistochemistry and comprehensive genomic profiling. RESULTS: Both patients experienced symptomatic improvement, and interval laryngoscopies revealed a reduction in papillomatosis burden. One patient has not required subsequent surgical debridement for almost 2 years. On pathologic examination of pretreatment papillomas from both cases, infiltrating T cells were evident in the papilloma stroma, and papilloma programmed death ligand 1 expression was absent. Papilloma mutational load ranged between three and six mutations per megabase for each case. From on-treatment biopsy tissue, a higher amount of intraepithelial T cells and programmed death ligand 1 expression were detected in the papilloma. CONCLUSION: Nivolumab appears to have promising activity in JO-RRP, and further clinical investigation with more patients in clinical trials is warranted. IMPLICATIONS FOR PRACTICE: To the authors' knowledge, this article is the first report describing clinical activity with a programed cell death-1 (PD-1) inhibitor to treat a rare but detrimental type of respiratory tract epithelial neoplasm that afflicts young adults. Two patients were treated, and tumor features, such as mutational load, were examined with the intent to stimulate future hypotheses for translational research. The safety and activity of PD-1 inhibitors in this population still need to be corroborated in clinical trials and should not yet be adopted into clinical practice.

Descriptive analysis of genetic aberrations and cell of origin in Richter transformation.

Richter transformation (RT) is a progression from chronic lymphocytic leukemia (CLL) to a more aggressive lymphoma, most often diffuse large B-cell lymphoma (DLBCL). Due to the rarity of the disease, data regarding the molecular profile and cell of origin (COO) of RT is limited. We performed immunohistochemistry analysis for COO determination and next-generation sequencing for gene mutation analysis in 11 RT patients. Seventy-nine percent of our patients were classified as non-GCB phenotype. Of the 57 unique mutations identified, the three most commonly mutated genes were TP53, TET2, and CREBBP. Neither TET2 nor CREBBP has been previously described in RT. Our analysis provides additional information to help guide further investigation of both the diagnosis and treatment of this complex and heterogeneous disease.

Salivary Gland Heterotopia in the Gastroesophageal Junction: A Case Series and Review of the Literature.

Heterotopia is defined as the presence of mature, histologically normal, tissue in unusual anatomic sites. When this heterotopic tissue forms a mass, it is called a choristoma. This case series describes 3 cases of gastroesophageal junction (GEJ) salivary heterotopias. While heterotopias are usually incidental findings, choristomas can clinically and endoscopically mimic carcinomas and might lead to unnecessary procedures for the patients. Clinicians should therefore be aware of this entity. Literature search, however, failed to show any reports of salivary gland heterotopias in the GEJ. In fact, literature review revealed only 6 reported cases of salivary gland choristoma in the gastrointestinal tract, none at the GEJ. In this case series, we report 2 cases of salivary gland heterotopia and one case of salivary gland choristoma arising at the GE junction. To our knowledge, this is the first series of its kind in the literature.

The Clinicopathologic Spectrum of IgG4-Related Disease

Immunoglobulin G4-related disease is a fibroinflammatory systemic disease that is characterized by focal or diffuse organ infiltration by immunoglobulin G4-bearing plasma cells. Immunoglobulin G4-related disease may affect any organ, and a high index of suspicion is necessary for early detection to avoid irreversible fibrosis, organ dysfunction, and death. Tumor-forming lesions are common radiological features of immunoglobulin G4-related disease that need to be differentiated from malignancies. The diagnostic approach requires the integration of clinical, biochemical, and radiographic manifestations with classic histopathologic features, which remain crucial to diagnosis. The histology of immunoglobulin G4-related disease is determined by a dense lymphoplasmacytic infiltrate, storiform fibrosis, and obliterative phlebitis in the presence of increased immunoglobulin G4-positve plasma cells. Although immunoglobulin G4-related disease forms a distinct, clinically independent disease category, many questions and problems remain unanswered, especially on its pathogenesis and the role of immunoglobulin G4. Advances in the understanding of immunoglobulin G4-related disease are likely to change the diagnostic approach in the future and create potential targets for therapeutic purposes. Here we describe the concept of immunoglobulin G4-related disease and the most recent knowledge in the clinico-pathological characteristics on this emerging disease. This study can guide clinicians in early diagnosis and prevent unnecessary surgical resections.

Incidental Metastatic Meningioma Presenting as a Large Liver Mass.

Meningiomas are slow growing neoplasms of the central nervous system (CNS). Most of the tumors are benign and distant metastasis from a benign meningioma is rare. Metastasis to the liver, although rare, usually presents with hypoglycemia or occurs in conjunction with a clinical history of an intracranial meningioma or following the resection of a prior CNS meningioma, thus making clinical diagnosis relatively easy. Here we present an unusual case of metastatic meningioma to the liver in a 54-year-old female who presented with an incidental liver mass by ultrasound. Her clinical history and physical examination were unremarkable. A partial hepatectomy revealed a meningioma on histology. Further investigation by imaging studies showed a frontal parasagittal dural mass which was confirmed to be a World Health Organization (WHO) grade 1 meningioma. To our knowledge, this is the first report of a clinically silent metastatic meningioma to the liver without either a concurrent or a previous history of meningioma. Precise diagnosis of this challenging case requires high clinical suspicion, histopathology, and immunohistochemistry.

Intravascular Large B-Cell Lymphoma Mimicking Temporal Arteritis.

Intravascular lymphoma is a rare type of lymphoma, characterized by growth of lymphoma cells within the microvasculature. The majority of the cases are of B-cell lineage, although rare examples of T or NK lineage have also been reported. The lymphoma is usually widely disseminated in the vascular spaces of any organ at the time of diagnosis including the skin and bone marrow. Lymph nodes are typically spared. The clinical picture depends on the specific organ involvement making the correct diagnosis very difficult. Here, we report a case of intravascular large B-cell lymphoma diagnosed postmortem on a 69-year-old African-American male who presented with unilateral proptosis and visual loss. An initial diagnosis of temporal arteritis was made and the patient received corticosteroids. However, the patient developed multiorgan failure and expired. On autopsy, there was disseminated intravascular lymphoma involving predominantly vessels within the heart, kidneys, liver, stomach, lungs, adrenal glands, small intestine, bladder, thyroid, and brain. Interestingly, there was also partial involvement of the retroperitoneal lymph nodes which is an unusual presentation in this disorder. Immunohistochemical staining showed that the lymphoma cells were positive for CD20, indicating B-cell phenotype. This case supports the "mimicking nature" of this rare entity with an unusual presentation with proptosis and visual loss, simulating temporal arteritis and a rare involvement of the retroperitoneal lymph nodes. The presentation of intravascular large B-cell lymphoma can vary, and the key to diagnosis is dependent on histopathology and immunohistochemistry. Increased awareness, early tissue diagnosis, and prompt chemotherapy are crucial for this otherwise lethal disease.

Synchronous Leydig Cell Tumor and Seminoma in the Ipsilateral Testis.

Leydig cell tumor is a rare sex cord tumor that accounts for 1-3% of all testicular neoplasms. Seminomas are more common and occur in 30-40% of testicular tumors. Leydig cell tumors are derived from undifferentiated gonadal mesenchyme and the concurrent development of the tumor and a seminoma which are derived from germinal epithelium in an ipsilateral testis is extremely rare. Here we report a case of ipsilateral Leydig cell tumor and seminoma occurring in a 38-year-old man with a left testicular mass. The key to diagnosis is dependent on histopathology and immunohistochemistry. To our knowledge, this is the first diagnosis of the two disease entities in a unilateral testis using immunohistochemistry. Increased awareness of the entity is important in order to distinguish Leydig cell tumor and seminomas from other malignancies due to difference in therapeutic management.

Myeloid sarcoma with megakaryoblastic differentiation presenting as a breast mass.

Myeloid sarcoma is an extramedullary tumor that consists of myeloblasts or immature myeloid cells. The neoplasm can occur in any part of the body, including the bone, periosteum, lymph nodes, skin, and soft tissue and they may occur de novo or in association with acute myeloid leukemia, myeloproliferative neoplasms and myelodysplastic syndromes. Most cases display a myelomonocytic or pure monoblastic morphology. Tumors with megakaryoblastic differentiation are extremely uncommon and may occur in association with transformation of a myeloproliferative disorder. Myeloid sarcoma presenting as a breast mass is very rare and diagnostically challenging. We report a case of myeloid sarcoma with megakaryoblastic differentiation in the breast of a patient with history of essential thrombocythemia. The mass was composed of undifferentiated pleomorphic malignant cells in trabecular cords and nests with many scattered giant malignant cells and brisk abnormal mitoses. On immunohistochemistry, the neoplastic cells were positive for CD61, CD31, CD34, Factor VIII and CD43 which confirmed the diagnosis. To our knowledge, this is the first report of myeloid sarcoma with megakaryoblastic morphology occurring in the breast. Here we discuss the clinicopathologic features of this rare entity and the challenges involved in making this difficult diagnosis.

Primary Langerhans Cell Histiocytosis of the Extrahepatic Bile Duct Occurring in an Adult Patient

Background: Langerhans cell histiocytosis is characterized by an abnormal proliferation of neoplastic Langerhans cells. Langerhans cell histiocytosis commonly affects the pediatric population, whereas presentation in adults remains a rare event. The presentation of Langerhans cell histiocytosis is highly variable, but the involvement of skin, bone, and lung is very common. Langerhans cell histiocytosis presenting as a bile duct mass is rare and usually occurs as part of a multiorgan system disease. Case Report: We present a case of Langerhans cell histiocytosis confined to the extrahepatic bile duct in a 62-year-old female patient with sclerosing cholangitis. The mass was composed of mononuclear cells with cleaved nuclei that were positive for CD68, S100, and CD1a as assessed by immunohistochemistry. Conclusion: This is the first report of Langerhans cell histiocytosis limited to the extrahepatic bile duct in an adult patient. We discuss the clinical manifestations and the challenges encountered in the diagnosis and treatment of this rare entity.