ABSTRACTAn 80-year-old Japanese woman with diabetes mellitus was admitted with gastrointestinal symptoms and pyrexia. At presentation, liver abscesses and severe hemolytic anemia were noted. Before detailed diagnostic evaluation and adequate treatment, she suddenly died 2.5 hours after admission. The autopsy and bacteriological examinations revealed liver abscesses and massive intravascular hemolysis caused by Clostridium perfringens as well as other miscellaneous critical pathological findings, including acute renal tubular necrosis, lung edema, and pulmonary fat embolism. In this article, the detailed autopsy results are described and clinicopathologic characteristics on Clostridium perfringens-related sudden death are discussed with a review of the literature.

ABSTRACTCoronavirus disease 2019 (COVID-19), first recognized in Wuhan, China, was recently declared a global pandemic by the World Health Organization (WHO). Advanced age and comorbid disease, well-known characteristics in the solid tumor population, have been reported as risk factors for severe disease and death. Cancer-related immunosuppression and its treatments also seem to play an active role in the prognosis, response, and clinical outcomes of these patients. The most effective combination therapy for COVID-19 is still under investigation, and the use of corticosteroids is controversial. Although, as a group, metastatic cancer patients are often considered not to be good candidates for ICU treatment, the individual prognosis should always come into consideration, even in a context of high pressure on medical facilities. We report the case of a stage IV prostate cancer patient infected with SARS-CoV-2 who required ICU admission and recovered from COVID-19 infection. Further studies are needed in order to identify accurate clinical prognostic criteria and provide the best treatment for these challenging patients.

ABSTRACTExtragonadal non-gestational choriocarcinoma (ENC) is an uncommon malignant tumor occasionally found in the gastrointestinal tract. ENC is characterized by a biphasic tumor growth with distinct areas of adenocarcinoma and choriocarcinoma differentiation. Primary choriocarcinoma of the colon is extremely rare, with only 21 cases reported in the literature. Most of the perforation of colorectal cancers occurs in the abdominal cavity, while abdominal wall abscess is rare; the psoas abscess associated with colon carcinoma is even less observed. Herein, we report the case of a 61-year-old female with poorly differentiated adenocarcinoma of the ascending colon and sigmoid, with choriocarcinomatous differentiation, masquerading a psoas abscess formation. Unfortunately, despite the aggressive therapy, the patient’s disease rapidly progressed, and she died within 2 months after the diagnosis. The typical morphological pattern, immunohistochemistry, and its correlation with serum β-human chorionic gonadotropin enabled a correct diagnosis.

JAK2 mutations are rare in de novo acute myeloid leukemia (AML), and JAK2-mutated acute myeloid leukemia (AML) patients usually have a previous history of myeloproliferative neoplasms (MPNs). Current advances in laboratory techniques, such as single nucleotide polymorphism array (SNPa) and next-generation sequencing (NGS), have facilitated new insight into the molecular basis of hematologic diseases. Herein, we present two cases of JAK2-mutated AML in which both SNPa and NGS methods added valuable information. Both cases had leukemogenic collaboration, namely, copy-neutral loss of heterozygosity (CN-LOH), detected on chromosome 9. One of the cases exhibited both JAK2 and IDH2 mutations, most likely having originated as an MPN with leukemic transformation, while the other case was classified as a de novo AML with JAK2, CEBPA, and FLT3 mutations.

A mandibular buccal bifurcation cyst is an inflammatory cyst that usually occurs on the buccal aspect of the permanent mandibular first molar of children. This lesion is diagnosed by an association of radiographic, clinical, and histological features. We report a bilateral case of mandibular buccal bifurcation cyst and discuss the main findings of this entity. A 7-year-old girl presented pain and delayed dental eruption in the posterior mandibular region. A cone beam computed tomography was performed and revealed hypodense lesions involving the crown and root of the mandibular first molars, with expansion of the buccal cortical and lingual tilting of the molar roots. A biopsy was carried out, and the common features of an inflammatory odontogenic cyst were histologically observed. The final diagnosis was bilateral mandibular buccal bifurcation cyst. Clinicians need to be aware of this diagnostic possibility in cases of mandibular cysts in children—especially when bilateral—to perform the correct treatment, which should not involve the extraction of the affected tooth.

Cholesterol crystal embolism is a rare and easily overlooked cause of colonic ischemia. The gastrointestinal tract is the third most common organ system affected by cholesterol emboli, second only to kidney and skin. Here we present a catastrophic case of gastrointestinal cholesterol crystal embolism leading to extensive post-operative bowel infarction and ultimately death. For a practicing pathologist, careful attention to the vessels of any ischemic bowel and recognition of the subtle but distinct angular imprint of cholesterol crystals facilitates prompt identification of the atheroemboli. In some cases, early identification may help mitigate further tissue damage. In more acute and severe cases, identification of the cholesterol crystal emboli may be important primarily for documentation of procedural complications.

Fibrous dysplasia (FD) is a relatively rare osseous disease of unknown etiology, wherein the normal bone is replaced by collagen-rich tissue, comprising of fibroblasts and variably abundant immature woven bone. Clinically, it may involve a single bone or multiple bones. It commonly arises in the jaw bone, skull, rib, and proximal femur. Those arising in the skull and the jaw are together termed “craniofacial fibrous dysplasia.” The differential diagnosis at this location includes meningioma and metastatic carcinoma. In this report, we highlight two diagnostically challenging cases presenting with orbital swelling and headache as the main complaints. Our first case was misinterpreted as meningioma on intraoperative squash smear, and paraffin sections revealed characteristic features of FD. The second case highlights the morphological feature of non-specific cystic degeneration occurring in FD. Radiographs in such cases show cystic swelling, which is indicative of a secondary aneurysmal bone cyst.

Infantile systemic juvenile xanthogranuloma (ISJXG) is an uncommon form of juvenile xanthogranuloma, a non-Langerhans cell proliferation of infancy and early childhood. In a small percentage of patients, the visceral involvement—most commonly to the central nervous system, liver, spleen, or lungs—may be associated with severe morbidity, and eventually fatal outcome. Here we describe the clinical and pathological findings of a 28-day-old girl with ISJXG who died with respiratory distress syndrome. She had few cutaneous lesions but massive liver and spleen infiltration; other affected organs were multiple lymph nodes, thoracic parasympathetic nodule, pleura, pancreas, and kidneys. Additional findings were mild pulmonary hypoplasia and bacteremia. Immunohistochemistry on fixed tissues is the standard for diagnosis. Immunophenotype cells express CD14, CD68, CD163, Factor XIIIa, Stabilin-1, and fascin; S100 was positive in less than 20% of the cases; CD1a and langerin were negative. No consistent cytogenetic or molecular genetic defect has been identified. This case demonstrates that the autopsy is a handy tool, because hepatic infiltration, which was not considered clinically, determined a restrictive respiratory impairment. In our opinion, this was the direct cause of death.