Uterine Sarcoma With EML4::NTRK3 Fusion: A Spectrum of Mesenchymal Neoplasms Harboring Actionable Gene Fusions.

NTRK gene fusions are part of a paradigm shift in oncology, arising as one of the main genomic alterations with actionability in the so-called "agnostic setting." In gynecologic pathology, the recent description of uterine sarcoma resembling fibrosarcoma and with NTRK rearrangements ( NTRK -rearranged uterine sarcoma) highlights the importance of recognizing clinicopathological cues that can lead to genomic profiling. Herein, we report the case of a 43-year-old woman presenting with vaginal bleeding and pelvic mass. Histopathology of the tumor showed moderately atypical spindle cells arranged in long fascicles reminiscent of fibrosarcoma, along with immunohistochemical positivity for S100, CD34, and pan-tropomyosin receptor kinase. This prompted RNA-sequencing and the finding of a rare EML4::NTRK3 fusion. Clinical, histologic, and molecular findings are described, in addition to discussions regarding differential diagnoses and possible implications of the findings in clinical practice.

Progressive multifocal leukoencephalopathy: a challenging diagnosis established at autopsy.

Progressive multifocal leukoencephalopathy (PML) is a feared entity that occurs most frequently in conditions of extreme immunodeficiency. The diagnosis is often made long after the onset of symptoms due to the physicians' unfamiliarity, and the unavailability of diagnostic tests in some medical centers. Although the incidence of PML is decreasing among HIV patients with the advent of highly active antiretroviral therapy (HAART), in Brazil this entity is the fourth highest neurological complication among these patients. The authors present the case of a middle-aged man who tested positive for HIV concomitantly with the presentation of hyposensitivity in the face and the right side of the body, accompanied by mild weakness in the left upper limb. The clinical features worsened rapidly within a couple of weeks. The diagnostic work-up pointed to the working diagnosis of PML after brain magnetic resonance imaging; however, the detection of the John Cunningham virus (JCV) in the cerebral spinal fluid was negative. HAART was started but the patient died after 7 weeks of hospitalization. The autopsy revealed extensive multifocal patchy areas of demyelination in the white matter where the microscopy depicted demyelination, oligodendrocytes alterations, bizarre atypical astrocytes, and perivascular lymphocytic infiltration. The immunohistochemistry was positive for anti-SV40, and the polymerase chain reaction of the brain paraffin-embedded tissue was positive for JCV. The authors highlight the challenges for diagnosing PML, as well as the devastating outcome of PML among HIV patients.

Traumatic injury to the internal carotid artery by the hyoid bone: a rare cause of ischemic stroke.

Central nervous system (CNS) ischemic events, besides being a common and devastating disease, are accompanied by severe disability and other morbidities. The cause of such events is not always that simple to diagnose, and among the young, a broad spectrum of possibilities should be considered. We present the case of a young man who presented two episodes of CNS ischemia with a 1 year gap between them, which occurred in the same situation while he was walking and carrying a heavy backpack. The second event first presented as a transient ischemic attack followed by a stroke the day after. The diagnostic work-up showed an indentation of the greater cornu of the hyoid bone over the internal carotid artery, which injured the media and intimal layers. At the arterial injury site, a micro thrombus was found, which explained the source of the embolic event to the CNS. The patient was operated on, and the procedure included the resection of the posterior horn of the hyoid bone, the resection of the injured segment of the internal carotid artery followed by carotid-carotid bypass with the great saphenous vein. The postoperative period and the recovery were uneventful as was the 5-month follow-up. We call attention to this unusual cause of stroke and present other cases reported in the literature.

Migrainous infarction: a rare and often overlooked diagnosis.

Migraine is a neurological entity and a well-known independent risk factor for cerebral infarction, which mostly afflicts the young female population. Researching focal neurological signs in this subset of the population with the diagnosis of a neurological ischemic event should always take into account the migraine as the etiology or as an associated factor. The etiology of central nervous system (CNS) ischemia is considerable. Migraine, although rare, also may be included in this vast etiological range, which is called migrainous infarction. In this setting, the diagnostic criteria required for this diagnosis is extensive. Herein, we present the case of a female adolescent who submitted to the emergency facility complaining of diplopia, dysarthria, and imbalance, which started concomitantly with a migrainous crisis with aura-a challenging clinical case that required extensive research to address all possible differential diagnoses.

Unusual presentation of high-grade neuroendocrine carcinoma of the Urinary bladder with small-cell and large-cell features.

High-grade neuroendocrine carcinoma of the urinary bladder comprehends small-cell and large-cell variants. It is a rare and aggressive neoplasm, mostly diagnosed in advanced stages. It is more frequently encountered among Caucasian men in the sixth decade of life. Urinary symptoms are the most common clinical presentation. Diagnosis is generally not troublesome once the lesions are easily detectable by imaging exams and cystoscopy. This neoplasia is associated with tobacco smoking, and is frequently associated with other carcinomatous components such as urothelial carcinoma, adenocarcinoma, and sarcomatoid carcinoma. The authors report a case of an apparently healthy female patient who presented cervical lymph node enlargement not accompanied by systemic symptoms. The supraclavicular lymph node biopsy revealed metastatic small cell carcinoma. The computed tomography scan showed a bladder wall nodular thickening, enlarged lymph nodes along the iliac, periaortic, mediastinal, cervical and supraclavicular chains, as well as an insufflating lytic bone lesion in the right iliac wing. The positron emission tomography-fluorodeoxyglucose (PET-FDG) added to these findings, the presence of a paraesophageal lymph node, lymphadenomegaly in the gluteal region and a vertebral lytic lesion in T10. Resected specimen of the bladder tumor revealed a high-grade neuroendocrine carcinoma with small-cell and large-cell features.

Cervical lymphadenopathy in childhood: nasopharyngeal carcinoma as a challenging diagnosis.

Nasopharyngeal carcinoma (NPC) is a carcinoma that arises from the nasopharyngeal mucosa and differs from other head and neck carcinomas by its unique histologic, epidemiologic, and biologic characteristics. NPC is rare in most countries, especially Europe and North America. However, it has a high incidence in several regions of South China. The incidence variability of NPC, among different geographical and ethnic groups, indicates a combination of genetic susceptibility, infection by Epstein-Barr virus and environmental factors. NPC is classified into three histological subtypes according to the 1991 World Health Organization classification: squamous cell carcinoma, nonkeratinizing carcinoma, and basaloid squamous cell carcinoma. The symptoms of patients with NPC are related to the primary tumor site and the degree of dissemination. Therefore, patients can remain asymptomatic during a long period of time. Imaging exams and biopsy of the tumor mass generally are sufficient to establish the diagnosis. NPC is a rare disease among children. The authors report a case of a 12-year-old boy who sought medical attention complaining of a progressive growing tumoral mass on the right side of the neck. The computed tomography images of the head and neck and the histological examination of a cervical lymph node biopsy diagnosed a metastatic NPC.