Resumo em Inglês:

ABSTRACT Twin reversed arterial perfusion (TRAP) sequence is a rare complication of monochorionic twinning whereby a donor twin perfuses an acardiac twin via aberrant vascular anastomoses. The resulting paradoxical retrograde blood flow supplying the acardiac twin is oxygen-poor, leading to some of the most severe malformations encountered in humans. Though the first descriptions of acardiac twins date back to at least the 16th century, the pathophysiologic processes which underpin the development of TRAP sequence are still being elucidated. Theories on the pathogenesis of TRAP sequence include deficiencies intrinsic to the embryo and primary abnormalities of the placental vasculature. Autopsy studies continue to provide clues to the underlying pathogenesis of TRAP sequence, and the characterization of the spectrum of manifestations that can be observed in acardiac twins. Herein, we present the clinical, autopsy, and molecular findings in a unique case of TRAP sequence. Novel findings include a primitive cloaca-like structure and chromosomal aberrations involving 6q11.1 and 15q25.1.

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ABSTRACT The present work reports the autopsy findings of a unique case characterized by fatal retroperitoneal hemorrhage following the traumatic rupture of bilateral renal angiomyolipomas. Renal angiomyolipomas are generally benign tumors with an unpredictable clinical course, ranging from asymptomatic to sudden rupture and hemorrhagic shock. They may be associated with genetic disorders such as tuberous sclerosis complex. The case under investigation is unprecedented in the medical literature due to its bilateral nature and fatal outcome. Autopsy analysis revealed an extensive retroperitoneal hemorrhage originating from bilateral ruptured tumors. Microscopic examination found features consistent with bilateral renal angiomyolipoma. Circumstantial information identified a traffic accident before the death, considering it as the cause of the tumors’ traumatic rupture. In this case, due to the severity of the situation, immediate medical measures—such as fluid resuscitation, coagulopathy correction, and surgical treatment, which are usually lifesaving—could not be performed. This led to the patient being declared dead at the scene of the crash.

Resumo em Inglês:

ABSTRACT We report the case of a 77-year-old male who suffered from hypertension and died suddenly. At autopsy, he was found to have hypertensive cardiomegaly and a dissecting syphilitic saccular aneurysm of the ascending aorta and arch with tamponade. Chronic aortic regurgitation, which is often seen in syphilitic aortitis, produces an additive effect to the concentric left ventricular hypertrophy seen in hypertension.

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ABSTRACT Fatty acid oxidation defects are a heterogeneous group of disorders related to the mitochondrial fatty acid oxidation pathway. Carnitine acylcarnitine translocase (CACT) is an enzyme responsible for the unidirectional transport of acylcarnitine across the inner mitochondrial membrane. This enzyme plays a crucial role in the oxidation of fatty acids. The autopsy pathology of the CACT deficiency is described in only a few cases. We describe the autopsy pathology of a child with CACT deficiency dominantly in the form of microvesicular steatosis of the hepatocytes, renal proximal tubular epithelia, cardiac myocytes, and rhabdomyocytes. The diagnosis was further confirmed on whole exome sequencing with compound heterozygous variants in the exon 1 (c.82G>T, p.Gly28Cys; likely pathogenic) and exon 5 (c.535G>A, p.Asp179Asn; uncertain significance) of the SLC25A20 gene. This case elucidates the histopathology of the liver and the detailed autopsy of a case of CACT deficiency from India.

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ABSTRACT Trisomy 13, known as Patau syndrome, is a common aneuploidy with a well-known clinical phenotype. This case report describes a trisomy 13 patient with unusual autopsy findings, including features resembling the Beckwith-Wiedemann Spectrum. Due to abnormalities of gestational ultrasounds, a prenatal karyotype of amniotic fluid cells was performed, which resulted in 47, XY+13. Autopsy microscopy studies identified leptomeningeal glioneuronal heterotopia, which was not described as belonging to Patau syndrome. Other atypical findings were diffuse hyperplasia of pancreatic islets of Langerhans and adrenals enlargement with marked adrenocortical cytomegaly, characteristically seen in the Beckwith-Wiedemann Spectrum. Molecular genetic tests were not performed for the Beckwith-Wiedemann Spectrum. Still, due to the rarity of both disorders, this report may support the evidence that trisomy 13 can affect tissue organization and lead to unusual histopathologic features resembling classic overgrowth disorders.

Resumo em Inglês:

ABSTRACT Pulmonary arteriovenous malformations (PAVMs) are abnormal vascular connections between pulmonary arteries and veins, often associated with hereditary hemorrhagic telangiectasia (HHT). Most PAVMs are asymptomatic, but life-threatening complications like pulmonary hemorrhage, brain abscesses, and paradoxical emboli can emerge, so prompt diagnosis and treatment are crucial. We report a case of sudden pediatric death in a two-year-old female with no past medical history. Initial vomiting and fast deterioration resulted in a sudden cardiac arrest. The postmortem examination found histological evidence of consistent, extensive lung damage. The absence of the characteristic symptoms made for some challenges when it came to diagnosis, showing precisely that in early life, you could well have many difficulties in catching PAVMs. This case highlights the need to take PAVMs into account as a potential cause of sudden death, particularly when there are no conspicuous symptoms. Awareness among forensic pathologists and consideration of genetic analysis for HHT in such cases is crucial for accurate diagnosis and management.

Resumo em Inglês:

ABSTRACT The lymphocyte-depleted classic Hodgkin lymphoma (LDCHL), the rarest subtype of classic Hodgkin lymphoma (CHL), is usually diagnosed at an advanced stage (stage IV) and one that unusually involves the liver, causing a rapidly progressive clinical course. We describe a 40-year-old immunocompromised man presenting with a progressive non-cholestatic jaundice and intermittent fever. The abdominal ultrasonography revealed a nodular liver with coarse echotexture and periportal hypodensities. The thoracic and abdominal contrast-enhanced computed tomography revealed right cervical and paraaortic lymphadenopathy, hepatosplenomegaly, diffuse mural thickening of duodenal and jejunal loops, and bilateral lobulated kidneys. Subsequently, he succumbed to his illness secondary to refractory septic shock. On postmortem examination, he was diagnosed with classic Hodgkin lymphoma (lymphocyte-depleted type) involving paraaortic and mediastinal lymph nodes based on morphology and immunochemistry findings. The lymphomatous process involved the liver (causing multiacinar confluent hepatic necrosis) and spleen, both showing tuberculous foci. This autopsy case depicts an uncommon case of acute liver failure due to infiltration of the liver by LDCHL in an HIV-infected patient. The findings of angiotropism and angioinvasion establish the pathological mechanism of liver failure (hepatocellular necrosis) in such cases.

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ABSTRACT The vasa vasorum of the large pulmonary vessels is involved in the pathology of COVID-19. This specialized microvasculature plays a major role in the biology and pathology of the pulmonary vessel walls. We have evidence that thrombosis of the vasa vasorum of the large and medium-sized pulmonary vessels during severe COVID-19 causes ischemia and subsequent death of the pulmonary vasculature endothelium. Subsequent release of thrombi from the vasa interna into the pulmonary circulation and pulmonary embolism generated at the ischemic pulmonary vascular endothelium site, are the central pathophysiological mechanisms in COVID-19 responsible for pulmonary thromboembolism. The thrombosis of the vasa vasorum of the large and medium-sized pulmonary vessels is an internal event leading to pulmonary thromboembolism in COVID-19.

Resumo em Inglês:

Abstract Primary cardiac tumors are rare. The cardiac sarcomas are the most common malignant cardiac tumors. These tumors have a dismal prognosis with an overall median survival of 25 months. Clinical features include dyspnea, arrhythmias, pericardial effusions, heart failure, and sudden cardiac death. The diagnosis is often challenging. Therefore, the cardiac imaging workup plays a central role in addition to a high clinical suspicion in the setting of atypical presentations that do not respond to standard therapies. The echocardiography, computed tomography, and cardiac MRI are crucial in clinching the diagnosis. Multimodal treatment with surgery, chemotherapy, and radiotherapy has been shown to improve outcomes, as opposed to using either of these modalities alone. We describe the case of a 30-year-old gentleman with COVID-19 infection who developed recurrent hemorrhagic pericardial effusions refractory to standard treatment and was eventually diagnosed as a case of pericardial angiosarcoma after his biopsy revealed the diagnosis and staging was performed using PET–CT–FDG scan. Our case re-emphasizes the importance of considering a malignant etiology early in the course of the disease presentation, especially in recurrent hemorrhagic effusions despite an inflammatory cytologic diagnosis of fluid. It also highlights the place for cardiac CT and MRI to ascertain the location and spread and to plan the further course of treatment. If diagnosed early, the estimated survival time can be prolonged by instituting a multimodal approach.

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ABSTRACT Lymphangiomas are rare benign tumors that mainly involve the head and neck region in pediatric patients. Lymphangiomas of the small bowel mesentery in adults are rarer. We present two cases of mesenteric lymphangioma with acute abdominal pain on presentation. Case 1: A 38-year-old female presented with abdominal pain, vomiting, fever, and difficult evacuation. On abdominal examination, she had an ill-defined, tender lump, and radiological findings raised a possibility of perforation peritonitis. Thus, exploratory laparotomy was planned. Per-operatively, a mesenteric mass was found, which, on histopathological evaluation, was found to be a mesenteric lymphangioma involving the bowel. Case 2: A 27-year-old male presented with abdominal pain and difficult evacuation. Radiological evaluation revealed a multilobulated lesion involving the mesentery and with differential diagnoses of mesenteric fibromatoses and inflammatory pseudotumor. Histopathological assessment of the resected mass revealed a lymphangioma that was limited to the mesentery. Owing to their rarity and non-specific presentation, mesenteric lymphangiomas are often misdiagnosed on clinical examination and imaging. Thus, histopathological examination is the gold standard to reach a definitive diagnosis.

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ABSTRACT Echinococcosis is a parasitic disease caused by infection with tiny tapeworms of the genus Echinococcus. Echinococcosis is classified as either cystic echinococcosis or alveolar echinococcosis. The common form is a zoonosis from goats and sheep that tends to cause liver lesions. The larval stage of Echinococcus multilocularis causes alveolar echinococcosis/alveolar hydatid disease. It is a zoonosis with field mice and tundra voles as intermediate and wild carnivores like foxes and wolves as definitive hosts. This zoonosis is highly uncommon compared to the other form known as cystic echinococcosis but poses a great human threat if untreated. We report the case of a young man who was working in the Kashmir Valley, North India, and presented with jaundice and right upper quadrant abdominal pain. Computed tomography revealed a large solid-cystic intrahepatic lesion measuring 125x118x123 mm, suggestive of a malignant tumor with central necrosis. A liver biopsy showed necrosis with PAS-positive membranes morphologically consistent with echinococcosis. Alveolar echinococcosis can present as a solid-cystic mass in the liver and can simulate metastatic malignancy.

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ABSTRACT Primary leiomyosarcoma with osteosarcomatous differentiation of the breast is an uncommon entity. We present the case of a 37-year-old female who presented with a lump in the breast and pulmonary lesions on PET-CT, for which she underwent a toilet mastectomy. Histopathological examination revealed a tumor with cells arranged in sheets. These tumor cells had moderate eosinophilic cytoplasm, highly pleomorphic, irregular hyperchromatic nuclei, coarse chromatin, and prominent nucleoli. Areas with spindle-cell morphology were noted. Osteoid was seen intermingling with the tumor along with numerous osteoclast-like multinucleate giant cells. A wide panel of Immunohistochemistry was applied, and Desmin, h-Caldesmon, SMA, and Vimentin were positive. The patient died 3 months post-surgery and had a recurrence at the surgical site.

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ABSTRACT Ovarian steroid cell tumors are rare, representing less than 0.1% of all ovarian neoplasms. Among the myriad causes of hirsutism, ovarian tumors account for 1% of the reported cases. We present the case of a 49-year-old parous postmenopausal woman who sought medical attention for hirsutism for 2 years. This case illustrates the unusual and interesting connection between rare ovarian pathology and the clinical manifestation of hirsutism in a postmenopausal patient. Her ultrasonography and MRI showed a right adnexal mass of solid-cystic consistency with thin septations. Her laboratory workup revealed high levels of total testosterone of 256 ng/ml (8.4-48.1ng/ml) and free testosterone of 7.36 pg/ml (0.2-4.1 pg/ml), while DHEAS - 234 µg/dl (35.4-256 µg/dl) and CA125 - 15.8U/L (0.0-35 U/L) were in the normal range. She underwent exploratory laparotomy with a total abdominal hysterectomy and oophorectomy. Histopathological examination and immunohistochemistry conclusively established the presence of a steroid cell tumor, specifically classified as "Not Otherwise Specified"(NOS), in the right ovary.

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ABSTRACT Papillary renal cell carcinoma (PRCC) is the second most common renal cell carcinoma (RCC), accounting for 10-15% of cases. Mucinous tubular and spindle cell carcinoma (MTSCC), on the other hand, accounts for only 1% of renal tumors and has a more favorable prognosis compared to PRCC. We report a 75-year-old female with a left upper pole solid renal mass displaying features of both papillary renal cell carcinoma (PRCC) and mucinous tubular and spindle cell carcinoma (MTSC). In this case, a shaggy luminal surface, multiple papillations, and psammoma bodies, absence of E-cadherin expression, and strong CD10 expression favored PRCC. Both immunohistochemistry and genomic analysis are critical to diagnose and differentiate tumors that may have overlapping features accurately.

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ABSTRACT Neuroendocrine breast cancer (NEBC) is a rare and heterogeneous entity. It most commonly presents a luminal phenotype and a worse prognosis. When diagnosed in an advanced stage, metastasis from another neuroendocrine tumor should be excluded. This case features a premenopausal woman with an oligometastatic breast large cell neuroendocrine carcinoma, estrogen receptor (ER) positive, and human epidermal growth factor receptor 2 (HER2) negative. Since the patient was very symptomatic at the presentation of the disease, chemotherapy was started. Complete radiological response of the metastatic disease was achieved, and the patient was then submitted to radical breast surgery and bilateral oophorectomy. She subsequently underwent radiation therapy. Since then and to date, she has been under endocrine therapy (ET) and a CDK4/6 inhibitor (CDK4/6i), with no evidence of malignant disease. Evidence to guide the choice of treatment for these tumors is currently scarce. In cases with oligometastatic disease, radical treatment should be considered. Given that this entity is rare, its reporting should be encouraged.

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ABSTRACT Biliary atresia (BA) is a fibro-obliterative cholestatic disease of infancy. The presence of cartilage in the resected tissue is an uncommon finding. We documented the presence of both mature and immature hyaline cartilage in the portal plate and the wall of the gallbladder in a 2-month-old girl infant with BA who had undergone Kasai portoenterostomy. The presence of cartilage could be part of a heterotopia or an uncommon connective tissue metaplasia. The presence of immature cartilage with the merging of the perichondrium with the soft tissue highlights a metaplastic etiology in the index case.

Resumo em Inglês:

ABSTRACT Esophageal melanocytosis is a rare entity defined by the proliferation of a melanocytic basal layer of the esophageal squamous lining and deposition of melanin in the esophageal mucosa. Esophageal melanocytosis is considered a benign entity of unknown etiology; however, it has been reported as a melanoma precursor. We report a case of esophageal melanocytosis in a diabetic and hypertensive 67-year-old male with recurrent dizziness and syncope for the past 6 months. Given his complaint of dyspepsia, he underwent an upper gastrointestinal endoscopy, in which an esophageal biopsy revealed the diagnosis of esophageal melanocytosis. The definitive diagnosis of esophageal melanocytosis can only be made by histological analysis. The histologic differential diagnoses include melanocytic nevi and malignant melanoma. Therefore, they need to be ruled out.

Resumo em Inglês:

ABSTRACT Giant hepatic hemangiomas are occasional in patients with cirrhosis. It remains a challenge to decide on the need for treatment and choose the most appropriate intervention. A 62-year-old woman was recently diagnosed with cirrhosis and complained of upper abdominal fullness, reduction in oral food intake, and weight loss of 6 kg over the last three years. Upper digestive endoscopy evidenced thin-caliber esophageal varices and significant extrinsic compression of the lesser gastric curvature. Abdominal computed tomography revealed an exophytic tumor in the left hepatic lobe, measuring 11.5 cm, which had progressive centripetal contrast enhancement from the arterial phase, compatible with hepatic hemangioma. Serum tumor markers were negative, and her liver function was unimpaired. The patient underwent surgical resection (non-anatomical hepatectomy of segments II and III) which had no immediate complications, and the histopathological evaluation confirmed cavernous hepatic hemangioma. Two weeks later, she was admitted to the emergency room with jaundice, signs of hepatic encephalopathy, and moderate ascites, and was further diagnosed with secondary bacterial peritonitis. As no perforations, abscesses, or fistulas were observed on subsequent imaging tests, clinical management was successfully carried out. This case highlights that giant hepatic hemangiomas may be symptomatic and warrant treatment. In the setting of cirrhosis and portal hypertension, physicians should be aware of the risk of hepatic decompensation following surgical resection, even in patients with Child-Pugh class A.