Submandibular lymph node metastasis of occult thyroid carcinoma first suspected to be a salivary gland tumor: a case report

Background When diagnosing and treating neck masses, various diseases need to be considered, including benign or malignant tumors, lymph node-related diseases, and cysts. Thus, there may be cases in which making a definitive diagnosis is difficult on the basis of blood testing and imaging alone. Case presentation The patient was an 80-year-old Japanese female who presented with swelling in the right submandibular area. Magnetic resonance imaging and ultrasonography revealed a solid tumor with inhomogeneous content continuous with the submandibular gland. Therefore, the clinical diagnosis was salivary gland tumor. Surgical treatment was performed, and intraoperative frozen-section examination demonstrated submandibular lymph node metastasis of thyroid carcinoma. After surgical treatment, blood test for thyroid gland function yielded normal results except for increased thyroglobulin levels. Further positron-emission tomography–computed tomography and ultrasonography were performed, in addition to fine-needle aspiration biopsy of the thyroid gland and other tests; however, no other thyroid abnormalities were observed. Fine-needle aspiration biopsy revealed no carcinomatous components. Close observational follow-up has been continued without thyroid gland treatment, and as of approximately 8 years postoperation, no recurrence, metastases, or thyroid carcinoma have developed. Conclusion The mass was lymph node metastasis of occult thyroid carcinoma. In general, occult thyroid carcinoma metastasizes to level II–V. To the best of our knowledge, this is the first report of submandibular lymph node metastasis alone of occult thyroid carcinoma.

Oral histiocytic sarcoma in a cat with mandibular invasion and regional lymph node metastasis

Case summary An 11-year-old female spayed domestic medium-hair cat presented for dental prophylaxis, at which time no oral mass was appreciated. Fifteen days after a dental cleaning, a mass expanding the oral mucosa of the rostral mandible was identified. An incisional biopsy revealed that the oral mucosa was infiltrated by neoplastic round-to-spindloid mesenchymal cells arranged in streams and small, dense aggregates consistent with an undifferentiated sarcoma. The patient was managed medically for approximately 6 months following the diagnosis, but, owing to declining health, euthanasia was elected and a post-mortem examination was performed. On post-mortem examination, the previously described neoplastic cells were infiltrating the rostral mandible and had metastasized to the right submandibular lymph node. Immunohistochemistry performed during the postmortem examination found that neoplastic cells were positive for Iba-1, CD18 and CD204, and negative for MUM-1, S100, Melan-A and E-cadherin, favoring a diagnosis of oral histiocytic sarcoma. Although recently recognized in cats, feline oral histiocytic sarcoma is rare, the tumor’s immunohistochemical profile is unstandardized, and the tumor’s behavior and prognosis are unclear. The diagnosis is challenging if small incisional biopsies are submitted and the neoplasm is poorly differentiated. This case report discusses the clinical, macroscopic, microscopic and immunohistochemical features of oral histiocytic sarcoma in a cat with mandibular invasion and submandibular lymph node metastasis. Relevance and novel information Feline primary oral histiocytic sarcoma is rare and tumor behavior and prognosis are unclear. This report broadens the immunohistochemical features of the tumor and recognizes mandibular invasion and submandibular lymph node metastasis.

Essential role of submandibular lymph node dendritic cells in protective sublingual immunotherapy against murine allergy

While sublingual immunotherapy (SLIT) is known as an allergen-specific treatment for type-1 allergies, how it controls allergic pathogenesis remains unclear. Here, we show the prerequisite role of conventional dendritic cells in submandibular lymph nodes (ManLNs) in the effectiveness of SLIT for the treatment of allergic disorders in mice. Deficiency of conventional dendritic cells or CD4+Foxp3+ regulatory T (Treg) cells abrogates the protective effect of SLIT against allergic disorders. Furthermore, sublingual antigenic application primarily induces antigen-specific CD4+Foxp3+ Treg cells in draining ManLNs, in which it is severely impaired in the absence of cDCs. In ManLNs, migratory CD11b+ cDCs are superior to other conventional dendritic cell subsets for the generation of antigen-specific CD4+Foxp3+ Treg cells, which is reflected by their dominancy in the tolerogenic features to favor this program. Thus, ManLNs are privileged sites in triggering mucosal tolerance mediating protect effect of SLIT on allergic disorders that requires a tolerogenesis of migratory CD11b+ conventional dendritic cells.

Disseminated acanthamoebiasis in a horse

Amoebic infections have been described in humans and animals, causing lesions in specific organs or as systemic infections. In both animals and humans, immunocompromised patients are predisposed to the infection. The present report described the macroscopic and histologic findings in a Quarter horse filly who presented with a systemic infection caused by Acanthamoeba spp. that was characterized by multinodular lesions in lung, kidney, heart, submandibular lymph node, and lip. Histopathology revealed dense inflammatory infiltrates composed of neutrophils, histiocytes, occasional multinucleated giant cells, and numerous intralesional trophozoites. Immunohistochemistry was positive for Acanthamoeba spp trophozoites in lungs, kidneys, heart, submandibular lymph node, and lip. No predisposing conditions were identified.

Clinical-epidemiological study of caseous lymphadenitis in goats in the state of Pernambuco

Caseous lymphadenitis (CL), a contagious infectious disease caused by Corynebacterium pseudotuberculosis, stands out with great economic relevance for goat breeding in the country because it is one of the main causes of carcass condemnation and intense depreciation of the leather of small ruminants. The objective was to carry out a descriptive study of the clinical and epidemiological aspects of CL in goats in the state of Pernambuco and also to evaluate the detection of C. pseudotuberculosis in milk, blood, and stool samples by real-time PCR. Six hundred and forty-three goats were evaluated, of which 76 (11.8%) presented clinical signs suggestive of CL. And 88.9% (24/27) of the breeding was considered focus. Among symptomatic animals, 25 were selected and submitted to the collection of abscess content for bacteriological isolation. Milk, blood, and stool samples were analyzed for PLD gene detection by real-time polymerase chain reaction (PCR). Out of the 25 samples of abscess content, 72% (18/25) were positive. The PLD gene was detected in the frequencies of 8% (2/25) and 4% (1/25) in milk and blood samples, respectively. Caseous lymphadenitis is possibly widespread in the dairy herds of goats in the state of Pernambuco, especially in adult animals, with a higher occurrence of submandibular lymph node abscesses. The preliminary detection of C. pseudotuberculosis by mammary and hematogenous pathways may contribute to future approaches on the mechanisms of organic dissemination performed by the pathogen. However, it has little relevance to diagnosing the disease.