Carcinoma Cuniculatum of the Maxilla Arising From Oroantral Fistula: A Report of an Extremely Rare Case.

Carcinoma cuniculatum (CC) is extremely rare in the maxilla. Here, we report a case of CC arising from an oroantral fistula (OAF). The patient was a 70-year-old Japanese man who was followed up for a non-closing OAF. Although there were no findings based on an intraoral examination, follow-up contrast-enhanced computed tomography and magnetic resonance imaging showed a 22-mm mass in the maxilla close to the OAF. Histologically, cystic and endophytic papillary proliferation of squamous epithelium with abundant keratinization mimicking rabbit burrows occupied the alveolar bone. This tumor was directly connected to the atypical proliferation of the covering epithelium of the OAF. The tumor cells showed mild cytological atypia and a few mitoses. Finally, the patient was diagnosed with CC arising from an OAF. CC is often misdiagnosed; nonetheless, the unique endophytic, branching, and tunnel-like structure is a hallmark of this tumor. We present the first well-documented case of CC arising from an OAF, discuss its diagnostic features, and highlight its differences from other common benign and malignant pathological entities.

Eosinophilic pancreatitis with serum IgG4-positivity, potentially associated with autoimmune pancreatitis.

A 70-year-old man presented with unprovoked weight loss and intermittent left upper quadrant tenderness for one-and-a-half month. Computed tomography revealed irregular cystic lesions in the pancreatic tail. Endoscopic ultrasonography (EUS) revealed pancreatic tail enlargement and giant, thick-walled cysts surrounding the pancreatic tail with no connection with the pancreatic duct. Endoscopic ultrasonography-guided fine-needle aspiration was performed on the enlarged pancreatic parenchyma and thickened cyst wall. Both biopsies showed hyper eosinophilia and few plasma cells. Endoscopic retrograde pancreatography revealed an irregular narrowing of the main pancreatic duct. Pancreatic juice cytology revealed substantial eosinophilia. Blood sampling showed an elevated eosinophil count and immunoglobulin G4 (IgG4) and immunoglobulin E (IgE) levels at the initial examination. We considered the patient to have eosinophilic pancreatitis (EP) with autoimmune pancreatitis, or alternately, EP with IgG4-related retroperitoneal fibrosis (RPF). Upon prednisolone administration, the abdominal pain improved, the peripheral blood eosinophil count decreased to zero, IgG4 and IgE levels decreased, pancreatic enlargement improved, and the cystic lesions disappeared. The condition did not recur within the following 3 years. Both EP and EP with IgG4-related RPF are rare etiologies of pancreatitis, and this case is very instructive.

A symptomatic intercalated duct lesion of the parotid gland: a case report with immunohistochemical and genetic analyses.

Intercalated duct lesions (IDLs) are usually asymptomatic. We report a case of IDL, in which a palpable mass formed. The patient was a 45-year-old Japanese male, who noticed a mass in the left parotid region. The nodular lesion was well-circumscribed, but did not have a fibrous capsule or exhibit infiltrative growth. It contained a small cystic space and consisted of basaloid cells arranged in a cribriform pattern and inner ductal cells. It had some solid areas of nest-like proliferation displaying mild cellular atypia. Immunohistochemically, the luminal cells were positive for cytokeratin (CK)7 and epithelial membrane antigen, and the abluminal cells were positive for CK5/6, p63, and DOG1. S-100 protein-positive stromal cells were also seen. The lesion's cells were all positive for SOX10, and the nuclei of some basaloid cells were positive for ß-catenin. The Ki-67 labeling index was 3.8%. The ductal cells contained diastase-digestion-resistant, Periodic acid Schiff-positive zymogen granules. Genetically, the lesion harbored a missense mutation in the CTNNB1 gene. We diagnosed the lesion as an IDL. As IDLs are usually small non-neoplastic lesions, symptomatic cases are rare. Based on its common immunohistochemical and genetic features, IDL may be a precursor of basal cell adenoma/adenocarcinoma, such as intercalated duct adenoma.

The implicated clinical factors for outcomes in 304 patients with salivary duct carcinoma: Multi-institutional retrospective analysis in Japan.

BACKGROUND: Salivary duct carcinoma (SDC) is a high-grade salivary malignancy that frequently occurs as the carcinomatous component of carcinoma ex pleomorphic adenoma. We herein examined the clinical factors affecting outcomes in a large cohort of SDC. METHODS: We selected 304 SDC cases and investigated clinical characteristics and the factors affecting outcomes. RESULTS: The median age of the cases examined was 68 years, the most common primary site was the parotid gland (238 cases), and there was a male predominance (M/F = 5:1). Outcomes were significantly worse when the primary tumor site was the minor salivary glands (SG) than when it was the major SG. Outcomes were also significantly worse in pN(+) cases (161 cases) than in pN0 cases, particularly those with a metastatic lymph node number ≥11. The cumulative incidence of relapse and distant metastases was significantly higher in stage IV cases than in stage 0-III cases. CONCLUSIONS: The absolute number of lymph node metastases, higher stages, and the minor SG as the primary tumor site were identified as factors affecting the outcome of SDC.

Leiomyosarcoma of the chest wall mimicking schwannoma resected by a video-assisted thoracoscopic approach: a case report.

Chest wall sarcomas account for <20% of all soft tissue sarcomas of which leiomyosarcomas represent only 1-4%. We report a case of thoracic leiomyosarcoma that resembled schwannoma in preoperative image studies. A 79-year-old man presented to our hospital with a chest wall tumor that increased in size over 3 months. Computed tomography of the chest revealed a 3-cm mass arising from the chest wall. Thoracic magnetic resonance imaging showed a solid tumor that was hypo-intense on T1-weighted imaging and iso-intense on T2-weighted imaging. Chest wall resection was performed using a video-assisted thoracoscopic approach after a frozen section examination revealed sarcoma. The histological diagnosis was leiomyosarcoma. Liver and multiple lung metastases were detected 5 years after surgery. Malignant tumors should be considered in any patient with chest wall tumors. The thoracoscopic approach could be an optimal treatment for chest wall tumor.

Hybrid Carcinoma of the Parotid Gland: An Extremely Rare Three Cases with an Immunohistochemical Analysis and a Review of the Literature.

Salivary hybrid carcinoma (HC) is defined as when two or more kinds of carcinoma exist at the same location in a single mass. We reestimated and examined three cases of salivary gland HC. Case 1 involved a 76-year-old male. Case 2 involved a 74-year-old female. Case 3 involved a 66-year-old male. Histologically, case 1 involved a combination of salivary duct carcinoma (SDC) and squamous cell carcinoma (SqCC). Immunohistochemically, the former was positive for gross cystic disease fluid protein (GCDFP)-15 and androgen receptor (AR). Case 2 involved a combination of SqCC and neuroendocrine carcinoma. Immunohistochemically the latter was positive for synaptophysin and neural cell adhesion molecule (NCAM). Case 3 involved a combination of SDC and epithelial-myoepithelial carcinoma (EMC). Immunohistochemically, the former was positive for GCDFP-15 and AR, whereas the inner cells of the latter were positive for cytokeratin 7, and the outer cells of the latter were positive for actin. Because of the transitional zone between SDC and EMC, it was speculated that high-grade SDC arose from low-grade EMC.

Pathological Complete Response to Neoadjuvant Chemotherapy in a Patient with HER2-Positive Squamous Cell Carcinoma of the Breast.

Squamous cell carcinoma (SCC) of the breast is a rare malignancy that usually has a triple-negative phenotype and poor clinical outcomes. Because HER2-positive SCC of the breast is extremely rare, its clinicopathologic features are understudied, and the effects of neoadjuvant chemotherapy including anti-HER2-targeted therapy on the tumor are unclear, although treatment resistance was described in some reports. In this study, we reported a case of HER2-positive SCC of the breast in which a pathological complete response to neoadjuvant chemotherapy was observed.

Periostin expression and its supposed roles in benign and malignant thyroid nodules: an immunohistochemical study of 105 cases.

BACKGROUND: Thyroid tumors are often difficult to histopathologically diagnose, particularly follicular adenoma (FA) and follicular carcinoma (FC). Papillary carcinoma (PAC) has several histological subtypes. Periostin (PON), which is a non-collagenous extracellular matrix molecule, has been implicated in tumor invasiveness. We herein aimed to elucidate the expression status and localization of PON in thyroid tumors. METHOD: We collected 105 cases of thyroid nodules, which included cases of adenomatous goiter, FA, microcarcinoma (MIC), PAC, FC, poorly differentiated carcinoma (PDCa), and undifferentiated carcinoma (UCa), and immunohistochemically examined the PON expression patterns of these lesions. RESULTS: Stromal PON deposition was detected in PAC and MIC, particularly in the solid/sclerosing subtype, whereas FA and FC showed weak deposition on the fibrous capsule. However, the invasive and/or extracapsular regions of microinvasive FC showed quite strong PON expression. Except for it, we could not find any significant histopathological differences between FA and FC. There were no other significant histopathological differences between FA and FC. Although PDCa showed a similar PON expression pattern to PAC, UCa exhibited stromal PON deposition in its invasive portions and cytoplasmic expression in its carcinoma cells. Although there was only one case of UCa, it showed strong PON immunopositivity. PAC and MIC showed similar patterns of stromal PON deposition, particularly at the invasive front. CONCLUSIONS: PON may play a role in the invasion of thyroid carcinomas, particularly PAC and UCa, whereas it may act as a barrier to the growth of tumor cells in FA and minimally invasive FC.

[A case of poorly differentiated pancreatic adenocarcinoma with spontaneous regression wherein retrospective rim enhancement findings were important for diagnosis].

A 66-year-old man with epigastric pain was admitted to our hospital for further evaluation of a pancreatic mass, as indicated on transabdominal ultrasonography performed by his family doctor. Using various imaging modalities, the 22-mm tumor was diagnosed as a cystic tumor with hemorrhagic necrosis. The tumor diameter reduced to 11mm over the course of 1 month. However, the tumor margin was irregular than that at the initial diagnosis, and circumferential rim enhancement was observed in equilibrium phase computed tomography images. Therefore, we diagnosed the patient with pancreatic ductal adenocarcinoma with a necrotic component. Distal pancreatectomy with splenectomy was performed, and the subsequent histological diagnosis was poorly differentiated adenocarcinoma. This case had an interesting course as described by the diagnostic images.

Epithelial-myoepithelial carcinoma ex-pleomorphic adenoma of the parotid gland: report of a rare case with immunohistochemical and genetic analyses.

Epithelial-myoepithelial carcinoma (EMCa) is a rare low-grade salivary malignancy. It is rare for EMCa to occur as the carcinomatous component of carcinoma ex-pleomorphic adenoma (PA). We examined one additional case of EMCa ex-PA, immunohistochemically and genetically. The patient was an 83-year-old female, who suffered from swelling of the right parotid region. Histologically, the tumor contained a hyalinized nodule, which displayed elastosis. The main tumor exhibited a bi-layered structure, involving inner ductal cells and clear outer myoepithelial cells. Immunostaining indicated that the inner cells were positive for epithelial membrane antigen, whereas the outer cells were positive for p40. On the genetic level, the carcinoma harbored no HRAS gene mutations, whereas fluorescence in situ hybridization (FISH) of the Pleomorphic Adenoma Gene1 showed splitting signals in the carcinomatous component. We diagnosed this case as EMCa ex-PA. It is necessary to differentiate EMCa ex-PA from myoepithelial carcinoma and clear cell carcinoma, and FISH is useful for such purposes.

Basaloid squamous cell carcinoma with adenoid cystic-like features of the head and neck region: A report of two cases.

The histology of basaloid squamous cell carcinoma (BSCC) can resemble that of adenoid cystic carcinoma (AdCC). Herein, we report two cases of BSCC with adenoid cystic-like features (BSCC-AdC). We collected cases of AdCC and BSCC of the head and neck region, extracted two cases with unusual histology, and reexamined them histologically and immunohistochemically. Case 1 involved an 81-year-old Japanese male, who had an elastic-hard mass on the left side of his tongue, and a biopsy examination suggested AdCC. Case 2 involved a 63-year-old Japanese male, who had a polypoid mass on his right hypopharynx. He was diagnosed with AdCC with high-grade transformation. Histologically, atypical cells in a myxoid stroma, which exhibited trabecular, nest-like, and/or cribriform growth patterns, and necrosis were observed in both cases. Case 2 displayed more marked cellular atypia than Case 1. Immunohistochemically, the tumor cells were diffusely positive for cytokeratin 5/6, p63/p40, SRY-related HMG-box 10 and Ki-67, but negative for other myoepithelial markers and p16. Finally, both cases were rediagnosed as BSCC-AdC. It is known that esophageal BSCC displays adenoid cystic-like features, and BSCC-AdC also sometimes occurs in the head and neck region. Clinicians should carefully differentiate BSCC-AdC from AdCC of the minor salivary glands and human papillomavirus-related carcinoma.

Hyperprogressive disease after treatment with pembrolizumab in lung adenocarcinoma: An autopsy case study.

Although immune-checkpoint inhibitors (ICIs) have become an important choice of treatment for advanced NSCLC, recent reports show hyperprogressive disease (HPD) after ICI administration. The clinico-pathological features of HPD still remain unclear. Here we report a 65-year-old man with lung adenocarcinoma who abruptly presented HPD two days after pembrolizumab administration. The primary tumor increased in size from 40 mm to 57 mm on the chest HRCT. The patient died on day 37 after pembrolizumab administration. The autopsy demonstrated widespread progression of cancer cells into the alveolar spaces and lymphangitic carcinomatosis in the left lung, with plenty of bloody pleural effusion. We compared the pathohistology and immunohistochemical expression of PD-L1 between the pretreatment biopsy material and posttreatment autopsy materials, and found a change in PD-L1 expression which may be related to HPD. We also discuss the possibility of HPD, pseudoprogression, and interstitial lung disease when there is evidence of tumor growth or ground glass shadows on chest images after ICI treatment.

Potential involvement of kinesin-1 in the regulation of subcellular localization of Girdin.

Girdin is an actin-binding protein that has multiple functions in postnatal neural development and cancer progression. We previously showed that Girdin is a regulator of migration for neuroblasts born from neural stem cells in the subventricular zone (SVZ) and the dentate gyrus of the hippocampus in the postnatal brain. Despite a growing list of Girdin-interacting proteins, the mechanism of Girdin-mediated migration has not been fully elucidated. Girdin interacts with Disrupted-In-Schizophrenia 1 and partitioning-defective 3, both of which have been shown to interact with the kinesin microtubule motor proteins. Based on this, we have identified that Girdin also interacts with kinesin-1, a member of neuronal kinesin proteins. Although a direct interaction of Girdin and kinesin-1 has not been determined, it is of interest to find that Girdin loss-of-function mutant mice with the mutation of a basic amino acid residue-rich region (Basic mut mice) exhibit limited interaction with kinesin-1. Furthermore, expression of a kinesin-1 mutant with motor defects, leads to Girdin mislocalization. Finally, consistent with previous studies on the role of kinesin proteins in trafficking a cell-cell adhesion molecule N-cadherin, Basic mut mice showed an aberrant expression pattern of N-cadherin in migrating SVZ neuroblasts. These findings suggest a potential role of Girdin/kinesin-1 interaction in the regulation of neuroblast migration in the postnatal brain.