Alpha-fetoprotein producing endometrioid carcinoma arising in an adenomyoma of the uterus.

We report a case of alpha-fetoprotein-producing endometrioid carcinoma (AFP-EC) that originated within an adenomyoma of the uterine corpus. A 76-year-old Japanese woman was incidentally discovered to have a uterine tumor along with multiple lung nodules. Upon surgical removal of the uterus, it was revealed that the tumor was situated within the adenomyoma. The tumor exhibited microfollicular structures and solid growth patterns, with hyaline globules, clear cell glands, and primitive tumor cells. Immunohistochemical analysis indicated the presence of germ cell markers, including AFP, SALL4, and glypican3, leading to final diagnosis of AFP-EC. Histopathologically, AFP-ECs exhibit characteristics similar to those of AFP-producing neoplasms in other organs. Furthermore, a nomenclature issue arises when distinguishing AFP-ECs from yolk sac tumors of the endometrium in older patients due to their shared features. The concept of retrodifferentiation or neometaplasia suggests that "endometrioid carcinoma with yolk sac tumor differentiation" or "endometrioid carcinoma with a primitive phenotype" may serve as more fitting terms for the diverse spectrum of AFP-producing neoplasms in the endometrium. In conclusion, this case underscores the diagnostic challenges posed by AFP-ECs arising from adenomyomas and emphasizes the need for refining the nomenclature and classification of AFP-producing neoplasms within the endometrium.

Clinicopathological correlations of endometrioid and clear cell carcinomas in the uterus and ovary.

Endometrioid carcinoma (EC) and clear cell carcinoma (CC) are associated with endometrial tissue hyperplasia and endometriosis, and they occur in the endometrium and ovaries. However, detailed differences between these tumors based on immunostaining are unclear; therefore, in this study, we aimed to analyze the clinicopathological correlations between these tumors using immunostaining and to develop new treatments based on histological subtypes. Immunohistochemistry was used to investigate differentially expressed hypoxia-associated molecules (hypoxia-inducible factor-1 subunit alpha [HIF-1α], forkhead box O1, prostate-specific membrane antigen, signal transducer and activator of transcription 3 [STAT3], hepatocyte nuclear factor 1ß [HNF-1ß], aquaporin-3, and vimentin [VIM]) between these carcinomas because of the reported association between CC and ischemia. Immunostaining and clinicopathological data from 70 patients (21 uterine endometrioid carcinomas [UECs], 9 uterine cell carcinomas, 20 ovarian endometrioid carcinomas [OECs], and 20 ovarian cell carcinomas [OCCs]) were compared. HIF-1α and prostate-specific membrane antigen expression levels were higher in UEC and OCC than in uterine cell carcinomas and OEC. STAT3 was slightly overexpressed in UEC. Additionally, forkhead box O1 expression was either absent or significantly attenuated in all ECs. VIM and AQ3 were highly expressed in UEC, whereas HNF-1ß expression was higher in OCC. UEC, OEC, and OCC were more common in the uterine fundus, left ovary, and right ovary, respectively. Ovarian endometriosis was strongly associated with EC. Our findings suggest that UEC and OCC share a carcinogenic pathway that involves HIF-1α induction under hypoxic conditions via STAT3 expression, resulting in angiogenesis. Furthermore, the anatomical position of carcinomas may contribute to their carcinogenesis. Finally, aquaporin-3 and VIM demonstrate strong potential as biomarkers for UEC, whereas HNF-1ß expression is a crucial factor in CC development. These differences in tumor site and histological subtypes shown in this study will lead to the establishment of treatment based on histological and immunohistological classification.

Uncommon case of cytopathological features of sialadenoma papilliferum.

Sialadenoma papilliferum, a benign and rare salivary gland neoplasm, accounts for 0.4%-1.2% of all salivary gland tumors and occurs primarily in minor salivary glands of the oral cavity. Here, we report a case of sialadenoma papilliferum and its associated cytological findings. A papillary tumor was incidentally detected on the palate of an 86-year-old Japanese man. Conventional oral exfoliative cytology was performed; the cytology smear exhibited epithelial clusters composed of atypical epithelial cells with a high nuclear/cytoplasm ratio and arranged in sheet or small papillary-like projections. Cytoplasmic vacuoles were also observed in the papillae. It was difficult to make a definitive diagnosis due to the presence of uncommon cytological features. The excisional biopsy specimen revealed histological features characteristic of sialadenoma papilliferum. Mutational analysis detected BRAFV600E mutation, which confirmed the diagnosis of sialadenoma papilliferum. To the best of our knowledge, no prior cytomorphological evaluations of sialadenoma papilliferum have been reported in detail. Oral exfoliative cytology specimens from salivary gland tumors can demonstrate uncommon cytomorphological features. A differential diagnosis of sialadenoma papilliferum can be based on the observation of mildly atypical epithelial cells that form small papillary-like structures.

Histopathological Aspects of the Prognostic Factors for Salivary Gland Cancers.

Salivary gland cancers (SGCs) are diagnosed using histopathological examination, which significantly contributes to their progression, including lymph node/distant metastasis or local recurrence. In the current World Health Organization (WHO) Classification of Head and Neck Tumors: Salivary Glands (5th edition), malignant and benign epithelial tumors are classified into 21 and 15 tumor types, respectively. All malignant tumors have the potential for lymph node/distant metastasis or local recurrence. In particular, mucoepidermoid carcinoma (MEC), adenoid cystic carcinoma (AdCC), salivary duct carcinoma, salivary carcinoma, not otherwise specified (NOS, formerly known as adenocarcinoma, NOS), myoepithelial carcinoma, epithelial-myoepithelial carcinoma, and carcinoma ex pleomorphic adenoma (PA) are relatively prevalent. High-grade transformation is an important aspect of tumor progression in SGCs. MEC, AdCC, salivary carcinoma, and NOS have a distinct grading system; however, a universal histological grading system for SGCs has not yet been recommended. Conversely, PA is considered benign; nonetheless, it should be cautiously treated to avoid the development of metastasizing/recurrent PA. The aim of this review is to describe the current histopathological aspects of the prognostic factors for SGCs and discuss the genes or molecules used as diagnostic tools that might have treatment target potential in the future.

CD8/PD-L1 immunohistochemical reactivity and gene alterations in cutaneous squamous cell carcinoma.

In recent years, several immune checkpoint inhibitors targeting programmed death-ligand 1 (PD-L1) or PD-1 have been developed for cancer therapy. The genetic background of tumors and factors that influence PD-L1 expression in tumor tissues are not yet elucidated in cutaneous squamous cell carcinoma (cSCC). CD8-positive tumor-infiltrating lymphocytes (TILs) are known to be related to tumor immunity. Here, we aimed to study the relationship between CD8/PD-L1 immunohistochemical reactivity and gene alterations in cSCC. Tumorigenic genes were examined to identify gene alterations using next-generation sequencing (NGS). We collected 27 cSCC tissue samples (from 13 metastatic and 14 non-metastatic patients at primary diagnosis). We performed immunohistochemical staining for CD8 and PD-L1, and NGS using a commercially available sequencing panel (Illumina Cancer Hotspot Panel V2) that targets 50 cancer-associated genes. Immunohistochemically, CD8-positive TILs showed a high positive score in cSCC without metastasis; in these cases, cSCC occurred predominantly in sun-exposed areas, the tumor size was smaller, and the total gene variation numbers were notably low. The tumor depth, PD-L1 positivity, and gene variation number with or without tumor metastasis were not related, but the gene variation number tended to be higher in cSCCs arising in non-sun-exposed areas. Tumor metastasis was more common in cSCC arising in non-sun-exposed areas, which decreased the number of TILs or CD8-positive cells. From a genetic perspective, the total gene alterations were higher in cSCC with metastasis. Among them, ERBB4 and NPM1 are presumably involved in cSCC tumorigenesis; in addition, GNAQ, GNAS, JAK2, NRAS, IDH2, and CTNNB1 may be related to tumor metastasis. These results provide information on potential genes that can be targeted for cSCC therapy and on immune checkpoint inhibitors that may be used for cSCC therapy.

Micronodular Thymic Carcinoma with Lymphoid Stroma: A Case Report.

Background. Micronodular thymic carcinoma (MTC) with lymphoid hyperplasia is believed to be the malignant counterpart of micronodular thymoma (MT) with lymphoid hyperplasia. Since MT and MTC share a similar morphology, MTC is considered a malignant form of MT; there have been a few malignant transformations from MT to MTC. We report a case of MTC with lymphoid hyperplasia. Case presentation. A 53-year-old woman presented with an incidental tumor on a chest X-ray. The resected tumor consisted of nodular epithelial nests and lymphoid tissue within a surrounding germinal center. Some epithelial nests showed apparent malignant morphology. Atypical epithelial cells with large vesicular nuclei formed nests, some of which showed comedo necrosis. These cells showed transition continuously to low-grade type B thymoma-like cells, demonstrating cord-like arrangements. Carcinomatous elements, expressed GLUT1, CD5, KIT, and BCL2; conversely, low-grade nests displayed attenuated expression of these markers. GTF2I point mutation and Langerhans/dendritic cells, which are indicators of favorable thymoma prognosis, were not detected. Due to pleural metastasis, the patient was treated with lenvatinib 27 months postoperatively. Conclusions. This is the first report of a partially low-grade, GTF2I-negative MTC. Histological and genetic findings might be predictive of tumor prognosis.

A Rare Case of Tracheal Crystal-Storing Histiocytosis Associated with Marginal Zone Lymphoma of Mucosa-Associated Lymphoid Tissue.

Crystal-storing histiocytosis (CSH) is a rare non-neoplastic histiocytic lesion with abnormal accumulation of immunoglobulin (Ig) light chain. CSH is associated with Ig overproduction by B-lymphoproliferative disorders (B-LPDs) or by persistent inflammatory diseases. Eighteen cases of pulmonary CSH have been reported. However, no case reports of tracheal CSH have been published. In this patient, we found a solitary tracheal tumor in an asymptomatic 60-year-old man on chest computed tomography scan. Histologically, the tumor comprised two different lesions. One lesion showed diffuse proliferation of spindle-shaped histiocytes with abundant eosinophilic granular cytoplasm. With immunohistochemistry, the histiocytic cells were positive for CD68, CD163 and Ig kappa light chain, and the cytoplasm was weakly positive for anaplastic lymphoma kinase (ALK) protein. Fluorescence in situ hybridization indicated no split signals for the ALK gene. Electron microscopy demonstrated many elongated or rhomboid-shaped dense crystals in the cytoplasm of histiocytes. The second lesion showed proliferation of CD20-positive small atypical lymphocytes mixed with Ig kappa chain-positive plasma cells. A diagnosis of CSH and concomitant mucosa-associated lymphoid tissue lymphoma was made. In this patient, unexpected ALK protein was detected in infiltrating histiocytes. Therefore, careful assessment of the ALK protein and gene was necessary to differentiate from other histiocytic disorders.

Short 57 kb CDKN2A FISH probe effectively detects short homozygous deletion of the 9p21 locus in malignant pleural mesothelioma.

Homozygous deletion (homo-d) of the cyclin-dependent kinase inhibitor 2A (CDKN2A) gene is frequently found in malignant pleural mesothelioma (MPM). Fluorescence in situ hybridization (FISH) is commonly used to detect chromosomal deletion, and sometimes reveals more frequent heterozygous deletion (hetero-d) compared with homo-d. In clinical practice, such CDKN2A FISH results belong to the 'borderline' homo-d rate, which makes it difficult to definitively diagnose MPM. Microdeletion, [<200 kilobase (kb)], can induce a 'pseudo' hetero-d signal in FISH assays with long probes owing to redundant probe reactivity. Thus, the present study hypothesized that shorter FISH probes can effectively detect the small deletion status of the CDKN2A gene and increase homo-d rate in MPM, which has high hetero-d and low homo-d status. The present study aimed to evaluate the effectiveness of a shorter CDKN2A FISH probe in diagnosing MPM. CDKN2A FISH with either a 222 kb long probe (L-probe) or a 57 kb short probe (S-probe) was performed in four MPM cases with high hetero-d and low homo-d patterns. Furthermore, immunohistochemistry for methylthioadenosine phosphorylase (MTAP) and quantitative (q)PCR analyses were performed to confirm the microdeletion of the 9p21 locus. The results demonstrated that all four MPM cases retained MTAP protein expression. CDKN2A FISH with L-probe revealed high hetero-d (cases 1-4; 73.3, 37.1, 59.2 and 64.8%, respectively) and low homo-d (cases 1-4; 12.1, 12.4, 25.4 and 22.2%, respectively). CDKN2A FISH with S-probe revealed high homo-d (cases 1-4; 96.8, 90.0, 87.5 and 82.6%, respectively), with low hetero-d (cases 1-4; 0.0, 1.2, 1.2 and 4.3%, respectively). qPCR analysis demonstrated no allele deletions of the MTAP gene and two-allele deletions of the CDKN2A gene in 3/4 cases. Taken together, these results suggest that the S-probe detects the short homo-d of the 9p21 locus more effectively than the L-probe in MPM. This can assist in solving diagnostic difficulties in cases involving high hetero-d with low homo-d.

Pulmonary wedge aspiration cytology for the rapid diagnosis of pulmonary tumor thrombotic microangiopathy: A case report.

Pulmonary tumor thrombotic microangiopathy (PTTM) is a cancer-related pulmonary complication characterized by rapid progression of dyspnea and pulmonary hypertension, occasionally causing sudden death. Given the condition of patients with dyspnea, lung biopsies are limited because of their invasiveness. A 72-year-old man presented with chronic atrial fibrillation and a high right heart load, as determined using ultrasonography. He had previously undergone resection of the left axillary skin secondary to extramammary Paget's disease (EMPD). Clinically, PTTM was suspected and pulmonary wedge aspiration cytology, collected from the pulmonary artery during catherization, was performed. Cytologically, the tumor demonstrated three-dimensional cell clusters with good cohesion and molding by the blood vessel lumen. Additionally, endothelial-like cells were observed at the periphery of the tumor clusters; fibrin was evident in the clusters. The tumor cells were large, round, and had high nuclear/cytoplasmic ratios. The nuclei demonstrated a variety of sizes and were irregularly shaped, with prominent nucleoli; cells undergoing mitosis were evident. The tumor cells were suspected of being poorly differentiated adenocarcinoma cells, consistent with PTTM. Two days after the aspiration cytology, the patient died and a pathological autopsy was performed. Histologically, the PTTM was determined to have caused the pulmonary hypertension and the primary PTTM site was apparently derived from the EMPD. For rapid diagnoses, an understanding of the tumor's cytological features is important and should contribute to early treatment intervention. Aspiration cytology, using pulmonary artery blood samples, during catherization is a useful tool for diagnosing PTTM.

An Autopsy Case of Acute Pancreatitis Caused by Cholesterol Crystal Embolization.

Cholesterol crystal embolization (CCE) shows a poor prognosis and it can cause ischemic organ damage due to a cholesterol embolism from atherosclerotic lesions in large blood vessels. Such an embolism mainly affects the kidneys and skin, although cases involving digestive organs have also been reported. We encountered an autopsy case of CCE with damage mainly to the digestive organs, including the pancreas. The patient had non-specific abdominal symptoms or image findings. Symptomatic therapy failed to save him. CCE can involve the digestive organs, and so must be differentiated from abdominal pathologies. Moreover, conventional treatments may be ineffective, and new treatments might thus be necessary.

Two cases of idiopathic multicentric Castleman disease with nephrotic syndrome treated with tocilizumab.

We report two cases of idiopathic multicentric Castleman disease (iMCD) with nephrotic syndrome (NS) treated with tocilizumab. Case 1 was a 58-year-old man diagnosed with iMCD prior to the onset of NS. Renal biopsy revealed membranous nephropathy, which was considered to be secondary membranous nephropathy associated with iMCD. Case 2 was a 49-year-old woman diagnosed with iMCD prior to NS. Renal biopsy revealed renal amyloidosis positive for Congo red staining and amyloid A protein immunostaining. In both the cases, the proteinuria improved after the initiation of glucocorticoid and tocilizumab therapy. Tocilizumab may be a good therapeutic choice for iMCD with NS.

Macroglossia in Beckwith-Wiedemann Syndrome Is Attributed to Skeletal Muscle Hyperplasia.

Macroglossia is a common feature in patients with Beckwith-Wiedemann syndrome (BWS). The underlying cause of macroglossia in BWS remains unknown, and further histological studies are required to uncover its etiology. We present the case of a 5-year-old girl who was diagnosed with BWS and underwent partial tongue resection for difficulties in articulation and aesthetics. The keyhole-shaped partial resection revealed a harder posterior side than the anterior. Microscopically, the posterior side consisted of dense subepithelial eosinophilic areas composed of an abundance of tightly packed skeletal muscle fibers that were arranged in a fascicular or storiform pattern. BWS-associated macroglossia results from skeletal muscle hyperplasia, consistent with true macroglossia. Therefore, tongue resection may be beneficial for such patients. Further studies are required to develop personalized surgical interventions for each patient with BWS.

Pulmonary tumor thrombotic microangiopathy associated with extramammary Paget's disease: An autopsy case report.

Pulmonary tumor thrombotic microangiopathy (PTTM) is histologically characterized by micro tumor cell embolism and intimal fibrocellular proliferation of pulmonary arteries or arterioles. We report a secondary case of PTTM associated with extramammary Paget's disease (EMPD). The patient was a 72-year-old man with exertional dyspnea. Clinical examinations found he had pulmonary hypertension and multiple osteolytic lesions of vertebra. Cytological analysis of pulmonary wedge artery sample detected malignant cells and he was dead before treatment was started. Multiple tumor embolisms (>17) were identified in pulmonary arteries or arterioles at autopsy, consistent with PTTM. Metastatic nodules were found in liver and lymph node. Furthermore, disseminated carcinomatosis of the bone marrow (DCBM) was seen. Immunostaining results pointed out that tumor cells possessed mammary gland phenotype. He had 4-years history of EMPD in the left axilla without recurrence, and immunohistochemistry results were the same as the autopsy specimen. Thus, we diagnosed the primary site of PTTM to be EMPD. Our case highlights the usefulness of the recent proposed classification of PTTM, potential association between PTTM and DCBM, and the necessity for long-term follow-up in EMPD. EMPD can rarely cause PTTM to manifest as a paraneoplastic syndrome.

A Case of Dendritic Cell Neurofibroma With Pseudorosettes.

Dendritic cell neurofibroma with pseudorosettes (DCNP) is a rare benign peripheral nerve sheath tumor. Till date, 34 cases of DCNP arising from various sites have been reported. Histopathologically, DCNP is known to present with characteristic pseudorosettes, in which a type II cell is surrounded by type I cells. In the present report, we discuss the rare case of a 63-year-old man diagnosed with DCNP on the left flank (size: approximately 10 mm). On microscopic examination of the resected lesion, we observed the characteristic pseudorosettes with centrally placed type I cells, which exhibited small, dark, slightly irregular oval nuclei with nuclear inclusions, surrounded by type II cells, which showed a large pale nucleus with a constriction, a small nucleolus, and mildly eosinophilic cytoplasm. The type II cells were positive for S-100, CD57, LAMP2, fascin, and factor XIIIa. Although previous reports have suggested that type II cells exhibit a dendritic form, our immunohistochemical analyses revealed that these cells were dermal interstitial dendritic cells.

A case of desmoplastic fibroma of bone with CTNNB1 point mutation.

Desmoplastic fibroma of bone (DFB), a bone tumor, is considered to be an osseous counterpart of desmoid-type fibromatosis (DF). Herein, we report a case of DFB with CTNNB1 point mutation. The 5-year-old male patient had complained of trismus and pain in the jaw. Magnetic resonance imaging revealed a mass in the left mandible. Radical treatment involved surgical resection. Microscopically, the lesion consisted of a bundle-like proliferation of uniform spindle-shaped cells with abundant collagenous stroma, which resembled DF. Immunohistochemical analysis revealed intranuclear accumulation of ß-catenin in the tumor cells. Based on clinical and histologic analysis, we diagnosed the patient as having DFB. We examined the CTNNB1 and APC sequence and found an A-to-G transition at codon 41 of CTNNB1; i.e., Thr was substituted by Ala. Our findings suggest that the dysregulation of Wnt/ß-catenin signaling pathway is related to the tumorigenesis of some cases of DFB. This hypothesis indicates that there are some cases of DFB in which nuclear positive expression of ß-catenin is useful for diagnosis.

Immunohistochemical Reactivity of Prostate-Specific Markers for Salivary Duct Carcinoma.

OBJECTIVES: NKX3.1, a transcription factor related to androgen expression, has recently been introduced as a diagnostic marker of prostate adenocarcinoma. Salivary duct carcinoma (SDC) is typically positive for androgen receptor (AR). Therefore, we hypothesized that NKX3.1 is a new immunohistochemical marker for SDC and aimed to investigate whether NKX3.1 staining in combination with other immunomarkers of prostate carcinoma could have a diagnostic or prognostic value in SDC. METHODS: Materials obtained from 42 resected SDCs were examined by immunohistochemistry using antibodies against AR, NKX3.1, α-methylacyl-CoA racemase (AMACR), prostatic acid phosphatase (PAP), and prostate-specific antigen (PSA). RESULTS: In immunoreactivity among SDC cases, 81.0, 35.7, 58.5, 33.3, and 0% were positive for AR, NKX3.1, AMACR, PAP, and PSA, respectively. AMACR and PAP immunoreactivity rates were higher in recurrence cases than in cases with no recurrence. CONCLUSIONS: NKX3.1 expression is useful for SDC diagnosis, but decreased NKX3.1 expression was not correlated with SDC progression. The immunoreactivity of AMACR and PAP could be useful for assessing prognosis in SDC, but immunohistochemical staining of prostate-specific markers should be interpreted with caution when determining whether a metastatic tumor is of prostate origin, especially when patients have a history of SDC.