A ciliated adenocarcinoma of the lung mimicking lung abscess and pneumonia.

This case report describes a 78-year-old man initially treated for pneumonia and lung abscess who was resistant to antimicrobial treatment and was eventually diagnosed with ciliated adenocarcinoma. Ciliated adenocarcinoma, a rare non-terminal respiratory unit (TRU)-type lung adenocarcinoma, presents a unique diagnostic challenge because of its similarity to pneumonia and lung abscesses. Morphologically, the ciliated adenocarcinoma in this case appeared to be a non-TRU type adenocarcinoma, with partial mucous epithelium, no visible extracellular mucus, thyroid transcription factor (TTF)-1 negativity, and mucin (MUC) 5AC positivity on immunostaining. The patient was considered to have ciliated adenocarcinoma based on the fact that the mucous epithelium was partial and extracellular mucus was not prominent. This case emphasizes the importance of considering malignancy in patients with non-resolving pulmonary infections.

Double somatic mutations in CTNNB1 and GNA11 in an aldosterone-producing adenoma.

Double somatic mutations in CTNNB1 and GNA11/Q have recently been identified in a small subset of aldosterone-producing adenomas (APAs). As a possible pathogenesis of APA due to these mutations, an association with pregnancy, menopause, or puberty has been proposed. However, because of its rarity, characteristics of APA with these mutations have not been well characterized. A 46-year-old Japanese woman presented with hypertension and hypokalemia. She had two pregnancies in the past but had no history of pregnancy-induced hypertension. She had regular menstrual cycle at presentation and was diagnosed as having primary aldosteronism after endocrinologic examinations. Computed tomography revealed a 2 cm right adrenal mass. Adrenal venous sampling demonstrated excess aldosterone production from the right adrenal gland. She underwent right laparoscopic adrenalectomy. The resected right adrenal tumor was histologically diagnosed as adrenocortical adenoma and subsequent immunohistochemistry (IHC) revealed diffuse immunoreactivity of aldosterone synthase (CYP11B2) and visinin like 1, a marker of the zona glomerulosa (ZG), whereas 11ß-hydroxylase, a steroidogenic enzyme for cortisol biosynthesis, was mostly negative. CYP11B2 IHC-guided targeted next-generation sequencing identified somatic CTNNB1 (p.D32Y) and GNA11 (p.Q209H) mutations. Immunofluorescence staining of the tumor also revealed the presence of activated ß-catenin, consistent with features of the normal ZG. The expression patterns of steroidogenic enzymes and related proteins indicated ZG features of the tumor cells. PA was clinically and biochemically cured after surgery. In conclusion, our study indicated that CTNNB1 and GNA11-mutated APA has characteristics of the ZG. The disease could occur in adults with no clear association with pregnancy or menopause.

Insulin-like Growth Factor II mRNA-binding Protein 3 is a Highly Sensitive Marker for Intravascular Large B-cell Lymphoma: Immunohistochemical Analysis of 152 Pathology Specimens From 88 Patients.

Intravascular large B-cell lymphoma (IVLBCL) is a rare type of aggressive extranodal large B-cell lymphoma characterized by the selective growth of lymphoma cells within the lumina of blood vessels, particularly capillaries. IVLBCL lacks mass formation, and its diagnosis can be challenging. We analyzed the utility of insulin-like growth factor II mRNA-binding protein 3 (IMP3) immunohistochemistry for IVLBCL diagnosis in various organs. Double staining with paired box 5 (PAX5) was performed for validation. Overall, 152 pathological specimens (111 positive and 41 negative for IVLBCL) obtained from 88 patients with a diagnosis of IVLBCL were stained for IMP3 and IMP3/PAX5. As negative controls, 40 pathology specimens from 38 patients with no history of IVLBCL or other B-cell lymphomas were stained for IMP3, which comprised 31 benign pathological specimens from 29 patients in whom malignancy was suspected, 7 cases of appendicitis with intravascular and/or intralymphatic lymphoid proliferations, and 2 cases of intravascular natural killer/T-cell lymphoma. All mononuclear cells with cytoplasmic staining were considered positive for IMP3 expression, but expression restricted to germinal center B cells was excluded from evaluation. All 111 IVLBCL pathological specimens were positive for IMP3 and IMP3/PAX5. In addition, 11 of the 41 specimens originally diagnosed as IVLBCL-negative showed IMP3/PAX5 double-positive cells, raising the suspicion of IVLBCL. However, of the 40 negative control samples, IMP3-positive non-germinal center B cells were detected in only 2 samples ( P = 0.0131) and no intravascular IMP3-positive B cells suspicious for IVLBCL were identified. Altogether, IMP3 immunohistochemistry is a highly sensitive marker of IVLBCL and can be a helpful adjunct for IVLBCL diagnosis.

FSH-producing pituitary neuroendocrine tumor as a cause of ovarian hyperstimulation syndrome.

Summary: Functioning gonadotroph tumors are rare neoplasms that can cause ovarian hyperstimulation syndrome (OHSS) in women of reproductive age. Here, we present a case of a follicle-stimulating hormone (FSH)-producing pituitary neuroendocrine tumor (PitNET) with irregular menstrual cycles and OHSS in a Japanese woman. A 34-year-old woman with bilateral multi-cystic ovarian mass was referred to our hospital for ovarian surgery. The imaging feature of magnetic resonance imaging (MRI) of the ovary and elevated estradiol levels with normal FSH and low luteinizing hormone (LH) levels led us to suspect the presence of a functioning gonadotroph PitNET. MRI revealed a 19-mm pituitary tumor, and increased tracer uptake was observed in the pituitary lesion on 111In-pentetreotide scintigraphy. Transsphenoidal tumor resection resulted in the resolution of the ovarian enlargement, normalization of her menstrual cycles, and spontaneous pregnancy. Immunohistochemistry (IHC) of the resected tumor for pituitary transcription factors, including steroidogenesis factor 1 (SF1) and estrogen receptor alpha, demonstrated positive immunoreactivity, whereas IHC for pituitary-specific positive transcription factor 1 was negative, suggesting that the tumor belonged to the SF1 lineage of PitNETs (gonadotroph tumor). The tumor cells showed positive expression of FSHß, while LHß was mostly negative. Consistent with the high pituitary tumor uptake observed on 111In-pentetreotide scintigraphy, the pituitary tumor showed positive expression of somatostatin receptor 2A. Detailed clinical and histological evaluations will provide useful information to understand these rare functioning gonadotroph tumors better. Learning points: Functioning gonadotroph tumors are very rare neuroendocrine tumors of pituitary origin. Women of reproductive age presenting with bilateral multi-cystic ovarian enlargement, irregular menstrual cycles, and hyperestrogenemia under unsuppressed follicle-stimulating hormone (FSH) levels should be evaluated for FSH-producing tumor. Raising awareness of OHSS due to functioning gonadotroph tumors is crucial to prevent unnecessary ovarian surgery. Comprehensive histological analysis may provide useful information to better understand the characteristics of functioning gonadotroph tumors.

Metastatic pancreatic cancer with multiple metastases confined to the large intestine: a case report and literature review.

The incidence and mortality rate of pancreatic cancer are increasing worldwide. Regional lymph nodes, liver, lung, and peritoneum are common sites of metastasis from pancreatic cancer, but the gastrointestinal tract is rare as a metastatic organ from pancreatic cancer. An 80-year-old man was referred to our department for a hypovascular pancreatic mass on contrast-enhanced computed tomography (CECT). Endoscopic ultrasound-guided fine needle aspiration revealed adenocarcinoma, and he was diagnosed with pancreatic cancer. No lymph nodes or distant metastases were detected by either CECT or gadolinium-enhanced magnetic resonance imaging, and we evaluated this case as borderline resectable. However, total colonoscopy for positive fecal occult blood tests revealed a reddish and hemorrhagic mucosal thickening in the ascending and sigmoid colon and rectum, which was inconsistent with primary colorectal cancer. Biopsy specimens from these sites revealed cytokeratin (CK)7-positive and CK20- and CDX2-negative adenocarcinoma, consistent with cancer of pancreatic origin. The patient underwent palliative chemotherapy with gemcitabine but died from COVID-19 infection eight months after diagnosis. Performing total colonoscopy as a preoperative screening is important for accurate cancer staging of patients with possible resectable pancreatic cancer.

Intraneural fibrosis within ilioinguinal nerve in inguinal hernia patients with preoperative pain: it's the sign of irreversible nerve injury, isn't it?

PURPOSE: Preoperative pain is known as one of the most powerful risk factors for chronic postoperative inguinal pain (CPIP), while its pathogenesis has not been fully elucidated. The aim of the present study was to evaluate patients with preoperative pain from the pathological perspective and discuss the potential pathogenesis of CPIP in those patients. METHODS: This was a single-institutional retrospective study. The study population was inguinal hernia patients with preoperative pain who underwent open anterior hernia repair for primary inguinal hernia with pragmatic ilioinguinal neurectomy during surgery between March 2021 and March 2023. The primary and secondary outcomes were proportion of collagen deposition and mucus accumulation within ilioinguinal nerve in those patients, respectively, which were evaluated histologically using Image J software. RESULTS: Forty patients were evaluated. Median value of proportion of intraneural collagen deposition was 38.3% (27.7-95.9). These values were positively correlated with the duration of pain (r2=0.468, P<0.001). Median value of proportion of mucus accumulation in ilioinguinal nerve was 50.1% (0-82.0). These values had no correlation with any clinicopathological variables. CONCLUSIONS: In the present study population, all patients with preoperative pain had intraneural fibrosis within ilioinguinal nerve, and its degree had a positive correlation with the pain duration.

Colonic amyloidosis: Rare endoscopic findings mimicking a depressed neoplastic lesion.

A colonic depressed lesion was found in a 77-year-old man and suspected as a neoplastic lesion using conventional endoscopy. Magnifying endoscopy, however, did not support it and biopsy revealed the lesion to be AL amyloidosis.

De Novo SCLC Transformation From KRAS G12C-Mutated Lung Adenocarcinoma With Excellent Response to Sotorasib: A Case Report.

The transformation to SCLC is a known mechanism of resistance against molecularly targeted therapies. This study reports a patient with untreated lung adenocarcinoma, characterized by a KRAS G12C mutation, which transformed into SCLC before treatment. Both the adenocarcinoma and SCLC components were responsive to sotorasib.

Multisystem inflammatory syndrome and lymphohistiocytic myocarditis after Covid-19 vaccine in a middle-aged woman.

We describe a 51-year-old otherwise healthy woman hospitalized for hypotension, fever, and weakness 4 days after the second-dose Covid-19 mRNA vaccine. Elevated inflammatory markers, natriuretic peptide levels and troponin levels, and slightly reduced left ventricular ejection fraction of 50% were noted. We also found the multiple organ damage, including mucocutaneous, gastrointestinal, and neurologic systems. In addition, we revealed the positive results for anti-nucleocapsid SARS-CoV-2 IgG, albeit negative for SARS-CoV-2 polymerase chain reaction testing, suggesting the prior asymptomatic Covid-19 infection. We finally diagnosed her as multisystem inflammatory syndrome after vaccination. Of note, we obtained myocardial specimen from the patients and demonstrated the lymphohistiocytic myocarditis, which is a rare form of myocarditis.

Asymptomatic pulmonary cryptococcosis presenting with mixed lesions of infiltrative and nodular shadow in an immunocompromised patient.

Pulmonary cryptococcosis (PC) is a rare fungal lung infection that usually occurs in immunocompromised hosts. We report a rare case of PC with asymptomatic and mixed lesions of infiltrative and nodular shadows. A woman in her 50s with a 7-year history of methotrexate treatment for rheumatoid arthritis (RA) presented with abnormal chest shadows on annual examination. Chest CT revealed two tiny nodules and two infiltrative shadows in the right lower lobe of the lung. We suspected lung cancer, cryptogenic organising pneumonia or RA-interstitial lung disease. However, transbronchial lung biopsy and positivity for serum cryptococcal antigen confirmed the diagnosis of PC. We initiated treatment with fluconazole, which drastically reduced the chest shadows without any adverse events. Since PC can present with several pulmonary shadows, it should be considered as a differential diagnosis of any pulmonary lesion.

Natural course of pulmonary hyalinizing granuloma over a decade.

Background: Pulmonary hyalinizing granuloma (PHG) is a very rare pulmonary disease characterized by multiple fibrosclerotic inflammatory lung nodules. The disease is supposedly caused by an unusual immune response. Case presentation: We present a case involving a 53-year-old female with a history of lumpectomy surgery due to invasive ductal carcinoma who was admitted for slowly progressive pulmonary nodules. The patient's elevated serum IgG4 level and the pathological findings obtained in surgical biopsy indicated IgG4-related lung disease. The nodules continued to enlarge despite administration of corticosteroid therapy, and we performed a second surgical biopsy to obtain a correct diagnosis. The pathological findings obtained in the second biopsy were different and consistent with the features of PHG. Conclusions: In this report, the radiological follow-up data obtained after lumpectomy surgery demonstrate the very early stage of PHG and the following radiological changes over a decade, and the two surgical biopsies support us to realize the pathological change from previous diagnosed disease before PHG.

White matter edematous change with moderate vascular lesions in pretreated acute stage of leukoencephalopathy with cerebral amyloid angiopathy.

A 79-year-old man presented with subacute onset of dementia. Brain magnetic resonance imaging revealed leukoencephalopathy in the posterior lobes with presence of microbleeds. Although clinical manifestation suggested a diagnosis of leukoencephalopathy associated with cerebral amyloid angiopathy (CAA), the patient died of sudden rupture of an aneurysm of the thoracic aorta two months after the onset of dementia. Autopsy revealed pathological features of advanced-stage Alzheimer's disease. Immunohistochemistry for amyloid-ß revealed CAA mainly affecting arteries but not capillaries. Klüver-Barrera staining revealed white matter edema predominantly in the occipital lobes without ischemic changes. Perivascular cuffing was found to be sparse, but there was no evidence of angiitis. Pathological findings suggest that leukoencephalopathy was caused by the disruption of the blood-brain barrier rather than ischemia. Because the present patient died before immunotherapy, his neuropathological findings could reflect the pathomechanism of the acute stage of leukoencephalopathy with CAA.

A multi-institutional study of salivary gland cytopathology: Application of the Milan System for Reporting Salivary Gland Cytopathology in Japan.

BACKGROUND: The Milan System for Reporting Salivary Gland Cytopathology (MSRSGC) is a risk-stratification reporting system that was introduced in 2018. The objective of this multi-institutional study was to evaluate the utility of the MSRSGC in Japan. METHODS: In total, 1608 fine-needle aspiration samples with matching histologic diagnoses were retrieved from 12 large institutions in Japan. The diagnostic categories of the MSRSGC were assigned prospectively or retrospectively, and the results were compared with the histologic diagnoses. RESULTS: The cases were classified as follows: nondiagnostic, 18.1%; non-neoplastic, 4.1%; atypia of undetermined significance, 11.5%; neoplasm-benign, 43.7%; salivary gland neoplasm of uncertain malignant potential, 9.6%; suspicious for malignancy, 3.6%; and malignant, 9.4%. The risk of neoplasm and the risk of malignancy in each MSRSGC category were as follows: nondiagnostic, 72.9% and 13.4%, respectively; non-neoplastic, 15.2% and 9.1%, respectively; atypia of undetermined significance, 77.9% and 24.9%, respectively; neoplasm-benign, 99% and 1.8%, respectively; salivary gland neoplasm of uncertain malignant potential, 94.8% and 37%, respectively; suspicious for malignancy, 100% and 89.7%, respectively; and malignant, 100% and 99.3%, respectively. The accuracy of the MSRSGC for diagnosing neoplasms was 97.8%, and its accuracy for diagnosing malignancy was 97.3%. Institutions that used Romanowsky-stained preparations had lower nondiagnostic rates and lower risks of neoplasm and malignancy in the non-neoplastic category. CONCLUSIONS: The MSRSGC is useful for risk stratification and quality control. Widespread use of the MSRSGC would improve the accuracy of salivary gland cytology and lead to better patient care in Japan.

Giant Pilomatrical Tumor With Broad Epidermal Components: An Example of Histological Diversity and a Potential Diagnostic Pitfall of Tumors With Pilomatrical Differentiation.

ABSTRACT: The diagnosis of pilomatricoma, the most common matrical tumor, is generally straightforward; however, it exhibits diverse histology associated with various morphological stages and several clinical variants, and matrical differentiation can occur in various neoplastic diseases. A 56-year-old man was admitted to our hospital to resect an 11.0-cm skin tumor on his right shoulder. Because of its large size and surface irregularities, including multiple erosions and ulcers, cutaneous malignancies were clinically suspected. Histologically, the tumor formed numerous nodules with marked matrical differentiation in the superficial to deep dermis. Although the tumor was macroscopically asymmetrical and irregular, each nodule was microscopically round-shaped and consisted of basaloid cells without marked atypia, atypical mitoses, or lymphovascular invasion. Immunohistochemically, the tumor cells were positive for beta-catenin, LEF-1, and PHLDA-1, consistent with their pilomatrical differentiation. We diagnosed the case as a giant pilomatrical tumor with uncertain malignant potential, considering its "contradictory" features, namely, the worrisome histoarchitecture, such as the asymmetrical silhouette, but bland-looking cytological appearance. Unlike typical pilomatrical tumors, this tumor contained numerous epidermal components with features similar to those of the dermal components, resulting in a unique macroscopic and histological appearance. Our case broadens the known histological diversity of pilomatrical tumors.

ACTH-independent production of 11-oxygenated androgens and glucocorticoids in an adrenocortical adenoma.

SIGNIFICANCE STATEMENT: Due to its rarity, biochemical and histologic characteristics of androgen and glucocorticoid co-secreting adrenocortical adenomas are largely unknown. Herein, we report a case of adrenocortical adenoma that caused marked hyperandrogenemia and mild autonomous cortisol secretion. In this study, we investigated serum steroid profiles using liquid chromatography-tandem mass spectrometry (LC-MS/MS) and histologic characteristics of the resected tumor. LC-MS/MS revealed highly elevated levels of 11-oxygenated androgens which have not been well studied in adrenal tumors. The expression patterns of steroidogenic enzymes determined by immunohistochemistry supported the results of steroid profiling and suggested the capacity of the tumor cells to produce 11-oxygenated androgens. Measurement of 11-oxygenated steroids should facilitate a better understanding of androgen-producing adrenocortical neoplasms.

The Expression of Insulin-Like Growth Factor 2 Messenger RNA-Binding Protein 3 in Langerhans Cell Histiocytosis and Langerhans Cell Sarcoma.

Langerhans cell neoplasms, which include Langerhans cell histiocytosis and Langerhans cell sarcoma, are tumors that originate from dendritic cells. Langerhans cell sarcoma is defined as a high-grade neoplasm with overtly malignant cytological features and the Langerhans cell-like phenotype, and generally has a poorer prognosis and more aggressive phenotype than Langerhans cell histiocytosis. Insulin-like growth factor 2 messenger RNA-binding protein 3 (IGF2BP3 or IMP3) is an oncofetal protein that is expressed in various cancer types; its expression is often associated with a poor prognosis and aggressive phenotype. Here, we used immunohistochemistry to evaluate IGF2BP3 expression in Langerhans cell neoplasms. IGF2BP3 expression was scored as negative (< 1%) or positive (≥ 1%) by immunohistochemistry. All 4 patients with Langerhans cell sarcoma (100%) and 6 of 22 pediatric (age < 18 years) patients with Langerhans cell histiocytosis (27.3%) had positive results for IGF2BP3; however, 16 of 22 pediatric patients with Langerhans cell histiocytosis (72.7%) and all 15 adult (age ≥ 18 years) patients with Langerhans cell histiocytosis (100%) had a negative result. Among patients with Langerhans cell histiocytosis, IGF2BP3 expression was independent of sex, location, prognosis, and BRAF V600E staining results. Taken together, these results indicate that IGF2BP3 expression may be a helpful marker for distinguishing Langerhans cell sarcoma from Langerhans cell histiocytosis in adult patients.

A pathological perspective to painful inguinal hernia: Report of two cases.

INTRODUCTION: Preoperative inguinal pain (painful inguinal hernia) is a well-known factor associated with chronic postoperative inguinal pain (CPIP). However, it remains unclear what preventive measures should be taken in such patients. CASE PRESENTATION: We report two patients with painful inguinal hernia who underwent pragmatic ilioinguinal nerve neurectomy during open anterior repair. The nerve was compressed by bulky spermatic cord lipoma in case 1 and by the hernia sac presenting over a few decades in case 2. Hematoxylin and eosin staining of the resected nerves revealed mucoid degeneration. Toluidine blue staining of resin-embedded nerve sections demonstrated that fully-myelinated axons had significantly decreased in case 1 and almost disappeared in case 2, indicating the development of massive demyelination of the ilioinguinal nerve in both cases. DISCUSSION: In cases where the injured nerve is left in situ, CPIP may occur since demyelinating neuropathy sometimes becomes irreversible. CONCLUSION: Planned nerve resection via open anterior inguinal hernia repair may be an option to prevent CPIP in patients with painful inguinal hernia.

Immunoglobulin A vasculitis without purpura in an elderly female patient: a case report.

Immunoglobulin A (IgA) vasculitis mainly affects the joints, skin, kidneys, and gastrointestinal tract; however, purpura is an essential diagnostic criterion. Here, we report an unusual case of IgA vasculitis without purpura in an elderly woman. A 76-year-old woman was admitted to our hospital complaining of diarrhea and abdominal pain. No skin rash, purpura, jaundice, or peripheral lymphadenopathy was observed. Endoscopy of the small intestine revealed severe mucosal sloughing in the duodenum, and a biopsy specimen showed severe erosive duodenitis. A decrease in coagulation factor XIII (FXIII) activity was also observed during laboratory blood tests. IgA immunostaining revealed granular IgA deposition on the walls of the interstitial small blood vessels. Although the patient showed no purpura or renal involvement, a diagnosis of IgA vasculitis was made based on the histopathology findings from biopsies. The administration of purified FXIII concentrate improved her symptoms immediately and facilitated regeneration of the duodenal villi. When gastroenterologists encounter severe erosive duodenitis or inflammation of the small intestine, IgA vasculitis should be listed as part of the differential diagnosis even without purpura and/or renal involvement. For a definitive diagnosis, measurement of FXIII and IgA immunostaining using duodenal biopsy specimens should be performed actively.