An atypical pacemaker pocket hematoma containing chyliform fluid.

Subcutaneous hematoma is a complication of cardiac device implantation. In most cases, it is drained or spontaneously reabsorbed. While cases of chylothorax are rare, and cases of pseudochylothorax even rarer, previous cases of accumulation of chyliform material in the subcutaneous pockets of cardiac devices are anecdotal. We present a case of a 60-year-old man with antiphospholipids antibody syndrome and rheumatoid arthritis, who underwent dual-chamber ICD implantation in December 2020; the procedure was complicated by a pocket hematoma, which required surgical drainage. After 7 months, the man returned owing to heart failure, with evidence of the reappearance of a large swelling in the ICD pocket; this was tolerated for months by the patient and was no longer controlled. We drained 100ml of gold-colored, odorless liquid, and found no evidence of blood material in the pocket. The liquid was not pus, as culture testing proved negative for bacterial growth. Chemical-physical examination revealed elevated cholesterol concentration (704 mg/dl) and low levels of triglycerides (80 mg/dl; plasma cholesterol values were 91mg/dl, and triglycerides 48 mg/dl). Microscopic examination revealed isolated leukocytes and rare erythrocytes immersed in mucoid material; cytological analysis showed a carpet of macrophages filled with cholesterol. This evidence supports the diagnosis of pseudochyle fluid, formed by the degradation of a hematoma left intact in a closed cavity for more than 6 months. This is an extremely rare case of chyliform fluid documented in an ICD pocket.

Takotsubo syndrome and pheochromocytoma: an insidious combination.

Pheochromocytoma is a rare adrenal tumor characterized by the secretion of catecholamines and vasoactive peptides. It can cause a catecholaminergic storm and lead to acute coronary syndromes. We present the case of a 53-year-old man, without any medical history, who arrived to the hospital following a spinal trauma due a fall. He presents back and retrosternal pain, with a clinical status of acute pulmonary edema, sinus tachycardia with left bundle branch block, left ventricular apical ballooning with depressed systolic function. Blood tests show a very important increase of Troponin and transaminases. A contrast chest-abdomen CT highlighted a right adrenal solid mass, with a diameter of 78mm, partial capsular laceration, compression of the inferior vena cava and the hepatic parenchyma. The clinical condition of the patient rapidly worsens from a respiratory and hemodynamic point of view, with cardiogenic shock, anuria and sepsis, refractory to all the medical treatments, until the patient died. The autopsy confirmed that the abdominal mass was a pheochromocytoma, broken after the trauma suffered. The resulting catecholaminergic storm caused a myocardial ischemia with Takotsubo syndrome, with cardiogenic shock. This unfortunate case confirms the pheochromocytoma as important risk factor for the onset of Takotsubo syndrome, and the how dramatic and severe a catecholaminergic storm can be.

Mucous membrane plasmacytosis of the nose in a patient affected by B-cell chronic lymphocytic leukemia.

Mucous membrane plasmacytosis (MMP) is a rare idiopathic condition characterized by infiltration of the mucosa by non neoplastic plasma cells. In this report we describe a case of mucous membrane plasmacytosis of the nose in a 72-year-old woman patient affected by B-cell chronic lymphocytic leukemia (B-CLL). Two different biopsies of the lesion showed diffuse plasma cell, lymphocyte and granulocyte infiltration compatible with granulation tissue. A complete exeresis of the neoplasm was performed endoscopically without complications, allowing the diagnosis of MMP; a monthly follow up was performed with no signs of local relapse 15 months after surgery. Topical steroid therapy with budesonide nasal spray was administered. There is no standardized treatment for MMP: we have reported good result of surgical approach in a unique case of nasal MMP in a patient with B-CLL; the relation between these two diseases deserves more studies.

Diagnostic controversies in vascular proliferations of the thyroid gland.

Vascular lesions are one of the most controversial issues in thyroid pathology. The differential diagnosis includes benign lesions on one side, i.e., endothelial reactive hyperplasia (Masson's "hemangioma") in goiter and hemangioma, and malignant tumors on the other, i.e., angiosarcomas and undifferentiated (angio)sarcomatoid carcinomas. Benign reactive endothelial hyperplasia with atypias mimicking malignant tumors may occur in long-standing nodular goiter, as a result of spontaneous hemorrhage followed by granulation tissue and fibrous organization. Alternatively, it may follow a fine-needle aspiration biopsy (FNAB) procedure. Angiosarcoma is a rare primary malignant thyroid tumor, mainly observed in endemic goiter areas displaying morphologic and phenotypical similar to those typical of angiosarcomas in other locations (including focal cytokeratin expression). The distinction between angiosarcoma and (angio)sarcomatoid anaplastic carcinoma is difficult and the true existence of angiosarcoma has been challenged. Other extremely rare vascular lesions or mimics in the thyroid include benign hemangioma and pseudo-angiosarcomatous variant of medullary carcinoma. The differential diagnosis between benign and malignant vascular conditions in FNAB material is extremely challenging, and the cytopathology report should be remarkably cautious, especially in poorly cellular and highly hemorrhagic cases: atypias in endothelial cells are not per se indicative of malignancy, being a common feature of reactive endothelial hyperplasia in infracted goiter nodules as well.

CD4-positive diffuse large B cell lymphoma identified by flow cytometry: two case reports.

We report two cases of diffuse large B cell lymphoma (DLBCL), both occurring in the small bowel, which coexpress PAX5, weak or no CD20 and the CD4 antigen. The CD4 was initially identified by flow cytometry and then confirmed by immunohistochemistry. CD4 is a representative marker for helper T-lymphocytes and is present on a subset of thymocytes, peripheral T cells and monocytes or macrophages. Unlike CD2 and CD5, no B cell fractions are known to express CD4. It might be hypothesized that the deregulated control of gene expression in malignant B cells, in particular PAX5, leads to the activation of some silent or repressed genes of T cell differentiation. Although lineage infidelity is described in some B lymphomas, it remains as an uncommon phenomenon; to our knowledge, cases reported here are the first two cases of DLBCL of the gastrointestinal tract coexpressing the CD4 antigen to be described to date.

Co-expression of plexin-B1 and Met in human breast and ovary tumours enhances the risk of progression.

BACKGROUND: Plex-B1, the receptor of Sema4D, has been implicated in tumour growth, angiogenesis and metastasis. The binding of Sema4D to Plex-B1 can trigger the activation of Met tyrosine kinase, thereby promoting cell dissociation and invasive growth. We tested the hypothesis that the expression of Plex-B1, either alone or in association with Met, can be of predictive value for tumour progression. METHODS: The expression and distribution of Plex-B1 and Met were investigated by immunohistochemistry and immunofluorescence in 50 human neoplasias originating in the breast and ovary, and correlated with clinical-pathological data at diagnosis. RESULTS: Plex-B1 and Met were individually expressed in 14% and in 24% of the tumours, respectively. Plex-B1 and Met were co-expressed in 24/50 cases (48%), and in the majority of these (83%) Met was tyrosine phosphorylated. The expression of Plex-B1 or Met alone showed no significant correlation with tumour aggressiveness, whereas advanced stage tumours (III-IV) frequently showed Plex-B1-Met double-positive (9/13). Tumours co-expressing Plex-B1 and Met were characterised by worse grading and higher incidence of lymph node metastases. Out of 22 tumours with lymph node metastases, as many as 19 were Plex-B1 and Met double-positive (p=0.0008), and 17 expressed phosphorylated Met (p=0.002). CONCLUSION: Plex-B1 assumes a predictive value for unfavourable outcome when co-expressed with Met.