Arteriovenous Malformation of the Uterus in a 41-Year-Old Woman Presenting as Uterine Bleeding.

An arteriovenous malformation (AVM) is a vascular lesion most frequently encountered in the brain, lungs, colon, and soft tissues of the extremities. However, rarely, an AVM may develop in the uterus, where it can cause abnormal and even life-threatening uterine bleeding. Here, we present the case of a 41-year-old G6P6 woman with abnormal uterine bleeding which resulted in a hemoglobin level of 10.2 g/dL. On gross examination, the uterus was enlarged measuring 17.5 cm x 12.0 cm x 10.0 cm, with a pronounced globoid appearance and bogginess on palpation. The cut surface was hemorrhagic and notable for numerous tortuous dilated spaces of variable sizes. These hemorrhagic, cavernous spaces were grossly apparent throughout the entire myometrium, but were found to be most prominent in the lower uterine segment of the anterior wall. Microscopic examination revealed an admixture of malformed vasculature comprising arteries, venules, and capillaries. The vessels showed prominent dilation and tortuosity with abrupt variation in the thickness of the media and elastic lamina, as highlighted by Von Gieson stain. Unlike in many other organ systems where AVMs are often considered congenital lesions, uterine AVMs are more often acquired lesions that develop following iatrogenic uterine trauma, namely cesarean section or curettage. Upon review of our patient's history, her final delivery was via cesarean section, after which she developed abnormal uterine bleeding. We present this case as a reminder to consider uterine AVM in cases of abnormal uterine bleeding, as it may be easily overlooked by even the most experienced pathologist.

Disseminated Mycobacterium tuberculosis: An Unusual Presentation with Associated Hemophagocytic Lymphohistiocytosis.

Hemophagocytic lymphohistiocytosis (HLH) is a rare, potentially fatal, and systemic hyperinflammatory syndrome with exacerbated and uncontrolled activation of histiocytes and lymphocytes against mature cells. Secondary HLH can occur in association with a myriad of underlying infections or malignancies. Our patient is a 38-year-old male prisoner with poorly controlled diabetes and no known other medical conditions. He was referred to our emergency department with three-week history of worsening malaise, weight loss, fever, bruising, and shortness of breath; imaging showed pneumomediastinum, lung nodule, and adrenal mass. Biopsy of the lung nodule revealed acid-fast bacilli. Furthermore, bone marrow biopsy showed foci of necrosis with associated acid-fast bacilli and hemophagocytosis highlighted by CD163 stain; consequently, secondary HLH was suggested. Hence, lab results were reviewed and found to satisfy five of the eight secondary HLH criteria. Moreover, ferritin was >10,000 ng/ml, which has been suggested to be highly suspicious for HLH. The patient was started on anti-MAC therapy. Unfortunately, the patient's status declined rapidly; he developed multi-organ failure and succumbed to disease. Later, his culture confirmed Mycobacterium tuberculosis. In conclusion, we presented a rare and challenging case of secondary HLH associated with disseminated Mycobacterium tuberculosis. A high index of suspicion is required for early diagnosis and treatment, and pathologists should be aware of Mycobacterium tuberculosis' association with secondary HLH.

Large Primary Neuroendocrine Tumor of the Liver in a 57-year-Old Female Presenting With MSSA Bacteremia.

Primary neuroendocrine tumors (NETs) are rare forms of malignancy, representing just .5% of known cancers and having an overall incidence of 0.2/100,000. The most common sites of origin are bronchopulmonary and gastrointestinal, most commonly the appendix, pancreas, and ileum. We report the case of a 57-year-old female who was admitted for refractory MSSA bacteremia and several weeks of abdominal pain. CT imaging done on presentation demonstrated a 12.5 x 19.4 x 17.3 cm heterogeneous right liver mass with associated mass effect. The patient was taken to the operating room and a right hepatectomy and cholecystectomy were performed without complication. Histological examination revealed necrotic tumor in sheets and nests with marked nuclear pleomorphism. Immunohistochemistry demonstrated positive staining for pancytokeratin, synaptophysin, chromogranin, and TTF-1, consistent with undifferentiated NET. While rare, NETs can originate from a variety of organs outside the gastrointestinal and bronchopulmonary tract, including the liver.

Indolent T-Lymphoblastic Proliferation in Idiopathic Multicentric Castleman Disease.

Benign and polyclonal proliferation of immature T cells in a lymph node with preserved morphological architecture is called indolent T-lymphoblastic proliferation (iT-LBP). Although overall rare, they have been described in association with both benign and malignant disorders including Castleman disease. We report the first case of idiopathic multicentric Castleman disease associated with iT-LBP, all previous reports of iT-LBP in Castleman disease were unicentric. A 37-year-old-male presented with 3 months of fevers and B-symptoms and was found to have enlargement of multiple bilateral lymph node sites on both sides of diaphragm along with splenomegaly. Anemia, elevated C-reactive protein, hypoalbuminemia, and elevated interleukin-6 levels were present. Biopsy of a lymph node showed features suggestive of idiopathic multicentric Castleman disease and iT-LBP. Bone marrow biopsy was unremarkable. Siltuximab and steroids were used to treat the condition.

Multiple myeloma: Detection of free monoclonal light chains by modified immunofixation electrophoresis with antisera against free light chains.

INTRODUCTION: Neoplastic monoclonal gammopathies are frequently associated with production of excess free monoclonal light chains. A sensitive method for detecting free monoclonal light chains in serum could provide a marker for residual/minimal residual disease and as an adjunct to serum protein electrophoresis to serve as a screening method for monoclonal gammopathies. METHODS: Conventional serum immunofixation electrophoresis was modified by applying undiluted serum samples, and staining for serum free light chains with antisera specific to free light chains. Washing/blotting of gels was enhanced to remove residual proteins that did not bind to the antibodies including intact monoclonal immunoglobulins. Results from this modified immunofixation electrophoresis were compared with results from commercially available MASS-FIX/MALDI assay. RESULTS: Monoclonal free kappa light chains could be detected to a concentration of about 1.78 mg/L and monoclonal free lambda light chains to a concentration of about 1.15 mg/L without the need for special equipment. Comparison of these thresholds with parallel results from a commercially available MASS-FIX/MALDI assay revealed the modified electrophoretic method to be more sensitive in the context of free monoclonal light chains. CONCLUSIONS: Modified serum immunofixation electrophoresis has been shown to detect low levels of monoclonal free light chains at a sensitivity suitable for the method to be used in detecting minimal residual disease, and potentially in a screening assay for monoclonal gammopathies. The disparity in the results with commercially available MASS-FIX/MALDI assay is postulated to be due to limited repertoire of reactivity of nanobodies of camelid origin.