The paraneurium and the tumefactive appearance of peripheral nerve neurolymphomatosis: illustrative case.

Background: Peripheral neurolymphomatosis (NL) is an often-misdiagnosed condition characterized by lymphomatous infiltration within the peripheral nerves. Its rarity and complexity frequently result in delayed diagnosis and suboptimal patient outcomes. This study aims to elucidate the role of the paraneurium (circumneurium) in NL, emphasizing its diagnostic and therapeutic significance.

Malignant rhabdoid tumor: Cyto-histologic correlation and immunohistochemical characterization of a rare pediatric malignancy and its differential diagnoses.

Malignant rhabdoid tumor of the kidney (MRTK) is a rare aggressive pediatric renal tumor which can be diagnosed via fine-needle aspiration (FNA) cytology and core biopsy. The diagnosis of MRTK is challenging, and requires morphologic, immunohistochemical and clinical correlation to distinguish it from other entities. The differential diagnosis includes Wilms tumor, desmoplastic small round cell tumor, rhabdomyosarcoma, synovial sarcoma, renal medullary carcinoma, and epithelioid sarcoma.

Well-Differentiated/Dedifferentiated Liposarcoma Arising in the Upper Aerodigestive Tract: 8 Cases Mimicking Non-adipocytic Lesions.

Well-differentiated (WDL) and dedifferentiated liposarcomas (DL) of the pharynx, larynx and oral cavity are rare, often mimicking benign lipomatous neoplasms or non-lipogenic mesenchymal tumors. Cases of WDL/DL arising in the upper aerodigestive tract, exclusive of the cervical esophagus, were reviewed. Morphologic features, ancillary studies, including fluorescence in situ hybridization (FISH) studies for CPM/MDM2, and clinical data was catalogued.

Increased ERBB2 Gene Copy Numbers Reveal a Subset of Salivary Duct Carcinomas with High Densities of Tumor Infiltrating Lymphocytes and PD-L1 Expression.

Salivary duct carcinoma (SDC) commonly expresses androgen receptor (AR) and HER2, giving rise to treatment implications. SDC may also express programmed-death-ligand-1 (PD-L1), a predictive marker of response to checkpoint inhibitors. PD-L1 can be associated with genomic instability and high density of tumor infiltrating lymphocytes (TILs).

First Line Androgen Deprivation Therapy vs. Chemotherapy for Patients With Androgen Receptor Positive Recurrent or Metastatic Salivary Gland Carcinoma-A Retrospective Study.

There is a lack of effective therapy for recurrent or metastatic salivary gland carcinoma. Androgen deprivation therapy has demonstrated efficacy in cases of salivary duct carcinoma (SDC) and high-grade adenocarcinoma not otherwise specified (NOS) that express androgen receptor. We conducted a single institution retrospective cohort study examining patients treated for recurrent/metastatic SDC or high-grade adenocarcinoma NOS of the salivary gland.

Mesenchymal chondrosarcomas showing immunohistochemical evidence of rhabdomyoblastic differentiation: a potential diagnostic pitfall.

The diagnosis of mesenchymal chondrosarcoma, a distinctive biphasic malignant neoplasm harboring the HEY1-NCOA2 gene fusion and consisting of primitive round to spindled cells admixed with foci of relatively mature hyaline cartilage, is usually straightforward by morphologic evaluation alone. However, in the setting of a limited biopsy, specimens lacking cartilage generate a broad differential diagnosis, encompassing a variety of other primitive sarcomas, including spindle cell/sclerosing rhabdomyosarcoma. Although a small number of cases of mesenchymal chondrosarcoma with aberrant skeletal muscle marker expression have been reported, pathologists are largely unaware of this potential diagnostic pitfall.

Comprehensive Genomic Profiling of Central Giant Cell Lesions Identifies Clinically Relevant Genomic Alterations.

Purpose: Comprehensive genomic profiling (CGP) can simultaneously detect clinically relevant genomic alterations (CRGAs) in hundreds of cancer-related genes and direct treatment toward patient-specific therapy options for many tumors. This pilot study aimed to use CGP to describe CRGAs present in central giant cell lesions (CGCLs) to characterize any possible underlying genomic drivers of CGCLs.

Materials And Methods: With institutional review board approval, electronic medical records were searched for patients with histologically confirmed CGCLs who underwent biopsy at Mayo Clinic from 2000 through 2014.

Fusion gene profile of biphenotypic sinonasal sarcoma: an analysis of 44 cases.

Aims: Biphenotypic sinonasal sarcoma (SNS) is a locally aggressive tumour that occurs in the sinonasal region. PAX3-MAML3 has recently been identified as a recurrent fusion gene event in this entity; however, a subset of tumours harbour alternative PAX3 rearrangement without the involvement of MAML3. In this study we sought to characterize the molecular profile of a large series of cases, with a special emphasis on tumours with alternative fusions.

Intramuscular dirofilariasis mimicking an orbital metastasis in a patient with breast cancer.

We present the unusual case of a 74 year-old female with a history of breast cancer who presented with acute painless orbital swelling and vertical diplopia. MRI revealed a focal enhancing mass within the superior rectus muscle. As the concern for metastatic disease was high, surgical biopsy was performed and revealed an unusual mimicker of metastatic disease, the parasitic infection dirofilariasis.

Prognostic features, human papillomavirus status, and epidermal growth factor receptor expression in oral squamous cell carcinoma in young adults.

Purpose: There is still debate in literature about the survival outcomes of patients who have cancer of the oral cavity when young. Hence the aims were (1) to estimate disease-free survival, overall survival, and cause-specific survival in patients who developed oral cavity squamous cell carcinoma between 18 and 40 years of age and (2) to assess the clinicopathologic factors including detection of human papillomavirus and epidermal growth factor receptor (EGFR) overexpression in primary lesions affecting recurrence.

Methods: This is a retrospective case-note review and reevaluation of histopathologic slides of patients treated more than 25 years.

Low-grade sinonasal sarcoma with neural and myogenic features: a clinicopathologic analysis of 28 cases.

Sarcomas of the sinonasal region are rare. We describe a distinct spindle cell sarcoma of the sinonasal region characterized by concomitant neural and myogenic differentiation. Consultation files and surgical cases from Mayo Clinic were reviewed.

Detection of human papilloma virus and p16 expression in high-grade adenoid cystic carcinoma of the head and neck.

Squamous cell carcinoma of the head and neck, particularly basaloid squamous cell carcinoma, may be difficult to distinguish from high-grade adenoid cystic carcinoma. Evidence of human papilloma virus (HPV) infection, particularly HPV 16, is frequently found in non-keratinizing oropharyngeal squamous cell carcinoma. Immunoreactivity for p16, a surrogate marker for HPV infection, often parallels the HPV infection status in oropharyngeal squamous cell carcinoma.

Veno-occlusive disease of the liver after blood and marrow transplantation: analysis of pre- and post-transplant risk factors associated with severity and results of therapy with tissue plasminogen activator.

We reviewed our blood and marrow transplantation (BMT) database from April 1982 to July 1996 and identified 111 of 474 patients with serum bilirubin concentration (SBR) > or = 34 micromol/l for two consecutive days within the first 20 days after related allogeneic or autologous BMT. Of the 111, 73 fulfilled the Seattle criteria for veno-occlusive disease of the liver (VOD) and had no other obvious cause for liver dysfunction. The patients were 16-60 years old (median, 39 years), and 41 were male (56%).