Linda Kocovski

Signet-ring cell melanoma: a potential diagnostic pitfall.

Abstract:Malignant melanoma is commonly known as the great mimicker and can present in various clinical manifestations and with diverse morphological variants. One of the rare histological variants is the signet-ring cell type. The signet-ring morphology has been reported in numerous other neoplasms including adenocarcinoma, lymphoma, liposarcoma, squamous cell carcinoma, and basal cell carcinoma. We report a rare case of primary signet-ring cell malignant melanoma in a 62-year-old man. He initially presented with an enlarging nevus on his right flank with surrounding erythema. A biopsy showed atypical epithelioid and signet cells with prominent nucleoli and occasional mitoses. Initial diagnosis favored metastatic signet-cell carcinoma of gastrointestinal origin. Review of the biopsy and immunohistochemical analysis revealed the malignant signet-ring cells stained with S100, vimentin, and melanoma cocktail, in keeping with melanoma. The signet-cell morphology can be found in a variety of other malignancies. To prevent potential misdiagnoses, thorough histological examination should be aided by an appropriate immunohistochemical panel to confirm melanoma and exclude erroneous differentials.

Femoral artery pseudoaneurysm due to Candida albicans in an injection drug user.

Candida arteritis is an uncommon condition but important to recognize due to the risk of significant morbidity and the difficulty in management of the enduring fungal infection. The authors report a rare case of a man with a femoral artery pseudoaneurysm with persistent Candida albicans infection, as a complication of infective endocarditis. The 23-year-old man, with a history of chronic intravenous drug use and Type I diabetes mellitus, presented with left groin pain, paresthesia of his left foot, and a pulsatile mass in the inguinal region. On imaging, he was found to have a pseudoaneurysm of the left common femoral artery, which later ruptured. Further investigation revealed vegetations on the mitral and aortic valves as well. Initial blood cultures were negative. He underwent multiple surgical interventions including replacement of the mitral and aortic valves and resection of the left common femoral artery with autogenous revascularization. In addition, he was commenced on intravenous antifungal therapy. Postoperatively, he continued to experience significant pain in the left groin and had two episodes of rerupture of the femoral artery that was consequently surgically repaired. Histological examination of the resected valves revealed vegetations with a mixture of fungal elements and bacterial cocci. The femoral artery resection specimens revealed evidence of infectious arteritis and the presence and persistence of C. albicans organisms in subsequent specimens. This case highlights the importance of an accurate diagnosis and aggressive management of fungal mycotic aneurysms in at-risk populations.

Radiologic and Histopathologic Features of Calcifying Pseudoneoplasm of the Neural Axis

Aim To describe the radiologic and corresponding histopathologic features of calcifying pseudoneoplasms of the neural axis. Methods Two cases of calcifying pseudoneoplasm of the neural axis were retrospectively reviewed. The first case was documented in a 64-year-old woman, who presented with lower back pain with radiation to her left leg. The second case was documented in a 70-year-old man, who presented with headaches. Medical records, radiologic and histologic findings, and related literature were reviewed. Results In the first case, imaging of the lumbar spine revealed a 3.8 × 2.2-cm calcified lesion at the level of vertebrae L5 and S1. A subsequent excision exposed an extradural lesion at L5. Histopathologic examination showed amorphous and granular calcifying material with occasional fibrohistiocytic and giant cell reaction, consistent with calcifying pseudoneoplasm of the neural axis. In the second case, imaging of the head revealed a 2.4 × 2.6-cm well-circumscribed, lobulated, calcified lesion within the basal frontal lobe. Subsequent resection exposed an intradural mass with a nodular arrangement of amorphous and granular calcifying material associated with fibrohistiocytic and giant cell reaction. Both patients had a favorable postoperative course and failed to show any clinical or radiologic sign of recurrence. Conclusion Calcifying pseudoneoplasm of the neural axis is an uncommon condition with an excellent prognosis but is often misdiagnosed due to its nonspecific clinical presentation and varied findings on radiology.

Sudden Cardiac Death: A Modern Pathology Approach to Hypertrophic Cardiomyopathy

Hypertrophic cardiomyopathy is one of the most common causes of sudden cardiac death among young adults and adolescents. Unfortunately, the first manifestation of the condition may be sudden death during exertion, such as sporting activities. Other clinical symptoms include exertional dyspnea, angina, and syncope. Postmortem examination often reveals asymmetrical septal thickening and mural plaque formation in the left ventricular outflow tract. Histologic analysis shows cardiac myocyte hypertrophy, myofiber disarray, and interstitial and replacement fibrosis. Molecular analysis for known genetic abnormalities is essential to genetic counseling of living relatives of decedents to assess and reduce the risk of sudden cardiac death from hypertrophic cardiomyopathy.

Amelanotic Melanoma Presenting with Plasmacytoid Morphology and BRAF V600 Mutation

Plasmacytoid melanoma is an unusual variant of malignant melanoma. The plasmacytoid morphology can be found in a variety of other malignancies including carcinomas, plasma cell neoplasms, lymphoproliferative disorders, and sarcomas. The authors report a rare case of plasmacytoid amelanotic malignant melanoma in a 78-year-old man presenting with an enlarging palpable, erythematous mass on his left posterior shoulder. A fine needle aspirate showed atypical findings with single amelanotic cells with high nuclear to cytoplasmic ratio, mono- and multi-nucleation with prominent nucleoli and intranuclear inclusions. Review of the excision and immunohistochemical analysis revealed the malignant plasmacytoid cells stained with vimentin, S-100, HMB-45, and other staining patterns consistent with melanoma. Initial evaluation was negative for other sites of disease. However, 4 months later, the patient was noted to have metastatic disease to his lungs and liver. Given that the tumor was noted to be BRAF V600R mutated, the patient was started on single agent dabrafenib. The plasmacytoid morphology can be found in a variety of malignancies. Melanoma should be considered in the differential diagnosis of any malignancy presenting with plasmacytoid features.

Association of Waist-Hip Ratio to Sudden Cardiac Death and Severe Coronary Atherosclerosis in Medicolegal Autopsies

Abstract Various modifiable and nonmodifiable risk factors, such as abdominal obesity, are known to affect the development of atherosclerotic cardiovascular disease and subsequent sudden cardiac death (SCD). The waist-hip ratio is a surrogate marker of visceral obesity that has been shown in various studies to be a better predictor of cardiovascular risk than the body mass index (BMI), a measurement of generalized obesity. Waist-hip ratio was measured prospectively on medicolegal autopsies performed for 1 year, in addition to standard measurements of BMI and heart weight, and histologic determination of severe coronary atherosclerosis (SCA, coronary artery diameter stenosis >75%). Logistic modeling was performed to determine any association between WHR, BMI, cardiovascular disease risk factors, heart weight, and SCD or SCA. Waist-hip ratio was not shown to be statistically significantly associated with either SCD (P = 0.68) or SCA (P = 0.14). Body mass index was shown to be significantly associated with SCA (P < 0.001), and heart weight was shown to be significantly associated with both SCD and SCA (P < 0.001, both). Waist-hip ratio, as a surrogate marker of central obesity and increased risk of atherosclerotic cardiovascular disease, is shown not to be statistically significantly associated with either SCD or SCA in postmortem cases.

Pleura Nodosum: Fetal Squamous Debris in an Unusual Location:

We present a pathologic-radiologic case of a fetus with a right extralobar bronchopulmonary sequestration that required intervention in the form of a thoraco-amniotic shunt for management of a right pleural effusion. The intervention was successful in reducing the pleural effusion and the infant was born at 39 weeks gestational age but required some respiratory support for the 1st day of life. The pulmonary sequestration was excised on day 7 of life and demonstrated several small nodules on its pleural surface. Histologic examination demonstrated that the nodules consisted of granulomatous plaques containing squamous epithelium and hairs. The nodules are similar to those described in amnion nodosum, when the amniotic membrane incorporates fetal skin within the superficial tissue layers of the placenta in cases of oligohydramnios. To our knowledge, this is the 1st reported case of nodules containing amniotic fetal squamous debris to occur on lung visceral pleura.

Retrospective Analysis of Oxycodone- and Cocaine-Related Deaths in Southwestern Ontario during 2003–2010

Oxycodone hydrochloride is a potent semisynthetic opioid analgesic with a primary role in moderate to severe chronic pain management. It was approved by Health Canada in 1996 for that purpose and added to the Ontario provincial drug formulary in 2000. Increases in oxycodone abuse and oxycodone-related deaths have been noted in both Canada and the USA since oxycodones introduction to the pharmaceutical market. A retrospective analysis was conducted, reviewing all of the medicolegal autopsies performed at a regional Ontario Forensic Pathology Unit, from 2003–2010. All cases that listed oxycodone and/or cocaine as cause of death were reviewed to ascertain trends in demographic data, preexisting prescription medication use, and concomitant drug use. Cocaine-related deaths were analyzed in order to contextualize oxycodone-related deaths in the setting of drug abuse. Oxycodone-related deaths were observed to increase from 2003–2010 and surpassed cocaine-related deaths in 2010. The proportion of female to male oxycodone-related deaths did not statistically differ during the study years. The proportion of female deaths was constant over the study period, however, male deaths showed a statistically significant increase by 23% from 2009–2010. Females were more likely to die from oxycodone rather than cocaine use, and the converse was seen in males. Among all oxycodone-related deaths over half of the decedents (53%) had a prescription for oxycodone. Oxycodone was also more likely to be reported with polysubstance use. This study illustrates how an abused prescription analgesic can be an ever-increasing burden on society even ten years after its release onto the market.

Acute Fatal Peritonitis: A New Organism for Consideration

A 40-year-old man died suddenly and unexpectedly at home. His comorbid conditions included central diabetes insipidus, obesity, and hypertension. Autopsy revealed acute and chronic pancreatitis with an abscess and associated purulent peritonitis. Peritoneal fluid cultures grew Raoultella planticola and a light growth of Candida albicans. The organism isolated, R. planticola, is a waterborne bacterium with limited previous clinical isolates causing morbidity but no previously described mortality. Vitreous humor analysis demonstrated concomitant acute water intoxication complicating the decedents diabetes insipidus. Discussion includes a review of the literature with a description of the eight previous cases of human infection with R. planticola, a recently described organism that was previously in the genus Klebsiella. The proposed fatal pathogenesis includes retrograde entry of the organism from the gastrointestinal tract via the pancreatic duct to the pancreas and subsequent peritonitis. This is the first reported fatality caused by this organism.