The Utility of Fine Needle Aspiration (FNA) Biopsy in the Diagnosis of Mediastinal Lesions.

Fine needle aspiration is a minimally invasive, low-morbidity, and cost-efficient technique for the sampling of mediastinal lesions. Additionally, ancillary testing on FNA samples can be used for the refinement of diagnoses and for treatment-related purposes (flow cytometry, cytogenetics, immunohistochemistry, and molecular diagnostics). Mediastinal lesions, however, can show a variety of lineages and morphologic features, giving rise to diagnostic dilemmas. As a result, the differential diagnosis can vary widely and becomes especially challenging due to the smaller sample size on FNA and the variability in component sampling. For appropriate patient management and to determine the correct treatment strategies, accurate pathologic diagnoses are paramount. In this review, we present the cytomorphologic features together with the immunophenotypic findings of mediastinal lesions, with emphasis on the diagnostic challenges and pitfalls in FNA cytology samples, including smears and cell block sections.

Diagnostic value of intraoperative fine-needle aspiration cytologic diagnosis versus frozen section-based histopathologic diagnosis in thoracic malignancies: A single institution's experience.

BACKGROUND: Primary lung cancer is the leading cause of cancer death in the United States. Most lung cancers are diagnosed in an outpatient setting, but a subset requires intraoperative diagnosis. Two intraoperative diagnostic methods are available, frozen section (FS) and fine needle aspiration (FNA) cytology. This study compares intraoperative FNA cytology and FS based diagnosis in thoracic malignancies within the same clinical practice. METHODS: Pathology reports from thoracic intraoperative FNA cytology or FS (January 2017-December 2019) were reviewed. Resection diagnosis was the gold standard. If unavailable, concurrent biopsy and final FNA cytology diagnosis were the gold standard. RESULTS: Of 300 FNA specimens (155 patients), 142 (47%) cases were benign, and 158 (53%) were malignant. Adenocarcinoma was the most common malignant diagnosis (40%), followed by squamous cell carcinoma (26%), neuroendocrine tumors (18%), and other (16%). Intraoperative FNA yielded 88% sensitivity, 99% specificity, and 92% accuracy (p < .001). Of 298 FS specimens (252 patients), 215 (72%) cases were malignant and 83 (28%) were benign. Adenocarcinomas was the most common malignant diagnosis (48%), followed by squamous cell carcinoma (25%), metastatic carcinomas (13%), and other (14%). FS yielded 97% sensitivity, 99% specificity, and 97% accuracy (p < .001). CONCLUSION: Our findings confirm FS is the gold standard for intraoperative diagnosis. FNA cytology may be useful as a non-invasive, inexpensive initial diagnostic tool intraoperatively, given the similar specificity (99% FNA, 99% FS) and accuracy (92% FNA, 97% FS). Negative FNA could be followed by the costlier and invasive FS. We encourage surgeons to utilize intraoperative FNA first.

Docetaxel treatment for widely metastatic invasive vulvar extramammary Paget's disease with multifocal bone metastasis.

•Invasive extramammary Paget's disease of the vulva is rare.•Distant metastasis has a very poor prognosis.•Given rarity of disease, no standardized treatment exists.•Single agent docetaxel is a viable treatment for metastatic invasive extramammary Paget's disease.

Ovarian Microcystic Stromal Tumor With Intraovarian Recurrence and Peritoneal and Omental Spread: A Case Report With Morphological, Immunohistochemical, and Molecular Analysis.

Microcystic stromal tumors (MCSTs) are rare ovarian stromal tumors. They harbor CTNNB1 or APC mutations, resulting in ß-catenin nuclear expression. To date, all MCST cases treated with oophorectomy or more extensive surgery have followed benign clinical courses. However, 1 of the 3 cases treated with ovarian cystectomy/tumor resection recurred in the residual ovary and iliac fossa 9 years after ovarian cystectomy. Here, we report a case of recurrent MCST in a 38-year-old woman. The patient underwent ovarian cystectomy for a 7.5 cm solid-cystic right ovarian mass, which showed classic morphological and immunophenotypical features of MCST. Four years later, the tumor recurred in the residual right ovary as a 21 cm mass, involving the pelvic peritoneum and omentum. Molecular analysis using next-generation sequencing revealed a single C TNNB1 exon 3 S37A mutation in the recurrent tumor. To the best of our knowledge, this is the second case of recurrent MCST, which presents more evidence that MCST has the potential to recur and spread locally. Rather than ovarian cystectomy/tumor resection, more aggressive surgery, such as unilateral oophorectomy, may be necessary to decrease the risk of recurrence. Long-term postsurgery follow up is needed, especially after simple ovarian cystectomy/tumor resection.

A Quantitative and Qualitative Assessment of Frozen Section Diagnosis Accuracy and Deferral Rate Across Organ Systems.

OBJECTIVES: Monitoring of frozen section diagnostic performance provides an important quality improvement measure. METHODS: Surgical specimens involving a frozen section diagnosis over a 3-year period were retrospectively reviewed. Glass slides were reviewed on cases with discordance. Discordance and deferral rates were calculated. RESULTS: Of 3,675 frozen section diagnoses included, 96 (2.7%) were discordant with the final diagnosis. Additionally, 114 frozen section diagnoses (3.1%) were deferred. The organ-specific discordance rates were lowest in breast and genitourinary specimens and highest for pancreas, lymph node, and gynecologic specimens. Deferral rates were highest in musculoskeletal, breast, and hepatobiliary cases and lowest in thyroid, parathyroid, and neuropathology cases. Discordance was explained by block-sampling error (45%), specimen-sampling error (27%), or interpretation error (27%). Discordant frozen section diagnoses from gynecologic specimens were responsible for 81% of specimen-sampling errors; frozen section diagnoses of lymph nodes, head and neck, and pancreas were responsible for 54% of interpretation errors; 51% of block-sampling errors involved lymph node evaluation for metastatic carcinoma. CONCLUSIONS: Careful gross evaluation and microscopic examination of multiple levels should minimize specimen-sampling error and block-sampling error, respectively. Periodic review of accuracy and deferral rates may help reduce errors and improve the overall performance of this essential procedure.

Cutaneous reactive B-cell lymphoid proliferations.

Cutaneous lymphoid hyperplasia (CLH), also known as cutaneous pseudolymphoma, is a spectrum of benign conditions characterized by reactive B- and T-cell cutaneous lymphocytic infiltrates. B-cell lymphoid proliferations are a heterogenous group of non-neoplastic cutaneous diseases that must be histopathologically distinguished from cutaneous B-cell lymphomas. These proliferations can be observed as reactive phenomena to infections, medications, allergens, neoplasms, and more. Furthermore, there are many inflammatory conditions that present with reactive B-cell infiltrates, including actinic prurigo, Zoon balanitis, Rosai-Dorfman disease, and cutaneous plasmacytosis. This review summarizes multiple cutaneous B-cell lymphoid proliferations within the major categories of reactive and disease-associated CLH. Further we discuss major discriminating features of atypical CLH and malignancy. Understanding the specific patterns of B-cell CLH is essential for the proper diagnosis and treatment of patients presenting with such lesions.

GPR65 (TDAG8) inhibits intestinal inflammation and colitis-associated colorectal cancer development in experimental mouse models.

GPR65 (TDAG8) is a proton-sensing G protein-coupled receptor predominantly expressed in immune cells. Genome-wide association studies (GWAS) have identified GPR65 gene polymorphisms as an emerging risk factor for the development of inflammatory bowel disease (IBD). Patients with IBD have an elevated risk of developing colorectal cancer when compared to the general population. To study the role of GPR65 in intestinal inflammation and colitis-associated colorectal cancer (CAC), colitis and CAC were induced in GPR65 knockout (KO) and wild-type (WT) mice using dextran sulfate sodium (DSS) and azoxymethane (AOM)/DSS, respectively. Disease severity parameters such as fecal score, colon shortening, histopathology, and mesenteric lymph node enlargement were aggravated in GPR65 KO mice compared to WT mice treated with DSS. Elevated leukocyte infiltration and fibrosis were observed in the inflamed colon of GPR65 KO when compared to WT mice which may represent a cellular mechanism for the observed exacerbation of intestinal inflammation. In line with high expression of GPR65 in infiltrated leukocytes, GPR65 gene expression was increased in inflamed intestinal tissue samples of IBD patients compared to normal intestinal tissues. Moreover, colitis-associated colorectal cancer development was higher in GPR65 KO mice than WT mice when treated with AOM/DSS. Altogether, our data demonstrate that GPR65 suppresses intestinal inflammation and colitis-associated tumor development in murine colitis and CAC models, suggesting potentiation of GPR65 with agonists may have an anti-inflammatory therapeutic effect in IBD and reduce the risk of developing colitis-associated colorectal cancer.

COVID-19: a Disease with a Potpourri of Histopathologic Findings-a Literature Review and Comparison to the Closely Related SARS and MERS.

Since the coronavirus disease 2019 (COVID-19) pandemic has hit the entire world, there is ample knowledge regarding its clinical course and prognostic biomarkers. Still, the pathophysiology of COVID-19 is poorly understood. Since the first guidelines published in February 2020 for autopsy of both confirmed and suspected COVID-19 cases, there has been an increasing number of autopsies and literature reporting histopathological findings. However, our knowledge about the immunological response of various organ systems to the virus, as well as response patterns, is inadequate but is essential to understand and initiate timely and targeted antiviral, anti-inflammatory, or anticoagulative therapy. Although severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is primarily considered a respiratory virus, current evidence shows that it causes life-threatening complications in almost all organ systems including the heart, brain, kidney, spleen, liver, and eyes. Hence, in this article, we reviewed the published case reports and case series in order to increase our understanding of COVID-19 pathophysiology. The main histopathological findings of the lungs include diffuse alveolar damage with activated type II pneumocytes, fibroblasts, protein-rich exudate, and hyaline membranes. Other significant histopathological findings include cardiomegaly, right ventricular dilation, splenic pulp atrophy, kidneys with severe podocytopathy, and collapsing glomerulopathy, and the brain showed hypoxic changes in the cerebellum and cerebrum. Furthermore, in this review, we also explained different pathological findings of SARS-CoV and MERS and compared them to SARS-CoV-2. This comprehensive review will improve our understanding of COVID-19 pathophysiology and various disease stages, hence promoting the application of targeted therapy.

Morbihan disease: A diagnostic dilemma: two cases with successful resolution.

Morbihan syndrome is a rare entity characterized by persistent erythema and solid edema of upper two-thirds of the face. Although its etiology is poorly understood, it is known to have a wide differential diagnosis and is frequently under-recognized.1-3 We report two such cases of Morbihan syndrome in patients that responded well to treatment with a combination of 2.5% hydrocortisone cream, brimonidine 0.33% topical gel, metronidazole gel and 100 mg doxycycline twice daily. This report emphasizes the necessity of biopsy for clinical correlation in cases of chronic facial edema. It also serves to highlight a potential association of Morbihan syndrome to diabetes mellitus through recently discovered pathophysiology of diabetes on the lymphatic system. It underscores the effectiveness of our therapeutic regimen in the context of other treatment regimen effectiveness. Finally, it highlights novel advances into the diagnosis and treatment of the disease.

A Case Study and Review of Literature of Eruptive Syringoma in a Six-Year-Old.

Syringomas are benign tumors originating from the intraepidermal portion of eccrine sweat ducts. A six-year-old African American female presented with multiple 2-3 mm hyperpigmented papules over the neck, upper chest, and axillae bilaterally. The lesions were non-tender, non-pruritic, and did not bleed when lightly scraped. A café-au-lait macule was incidentally found in the mid-back of the patient. Histopathologically, multiple small ducts displaying a tadpole-shaped/paisley-tie pattern with fibrotic stroma were identified on hematoxylin and eosin staining. Epithelium showing nests of cells with basaloid appearance and dilated glands filled with eosinophilic material were also identified. These histopathologic findings were consistent with a diagnosis of eruptive syringoma. The patient was treated conservatively, and the lesions subsided without intervention. In most patients requesting treatment, isotretinoin is used; however, this may be an unnecessary measure in many patients. Overall, this case was significant due to the patient's young age, ethnicity, and clinical improvement in the absence of treatment.

Kikuchi Fujimoto disease: sinister presentation, good prognosis.

Kikuchi-Fujimoto disease (KFD) is a rare, benign, self-limiting necrotizing lymphadenitis of unknown etiology. The disease can affect people of all ages and of any sex and ethnicity. Tissue biopsy is needed for accurate diagnosis. The condition commonly masquerades as more sinister conditions such as malignancy and rheumatologic disorders, but has a much better prognosis. Treatment is generally supportive but patients may require corticosteroids with eventual spontaneous resolution. We discuss a case of KFD in a 34-year-old male and highlight the need for prompt and accurate diagnosis.

An Objective Histopathological Scoring System for Placental Pathology in Pre-Eclampsia and Eclampsia.

Background and objective Pre-eclampsia and eclampsia are common complications in pregnancy, and they lead to uteroplacental vascular insufficiency. More than 38% of pregnant women succumb to seizures without meeting the clinical criteria for pre-eclampsia or eclampsia. This highlights the importance of a confirmatory diagnosis of pre-eclampsia or eclampsia using the histopathological changes seen in the placenta. Hence, the present study aimed to validate an objective histopathological scoring system of the placenta for an appropriate diagnosis of pre-eclampsia or eclampsia. Material and methods In this prospective study spanning two years, 50 cases of pre-eclampsia/eclampsia and 50 control subjects with normal placenta were included. The histomorphological changes in the placenta were examined for both groups and a scoring system was formulated to assess the severity of pre-eclampsia/eclampsia syndrome. A maximum score of 2 and a minimum score of 0 was assigned for maternal floor infarcts, calcification, villous basement membrane thickening, and fibrin deposition. Syncytial knots were assigned a minimum score of 0 and a maximum score of 1. The association of various placental histopathological variables with a clinical diagnosis of pre-eclampsia, eclampsia, and control was analyzed using the chi-squared/Fisher's exact test. A one-way analysis of variance (ANOVA) test was used for comparing objective histopathological scores between pre-eclampsia, eclampsia, and control groups. A p-value of less than 0.05 was considered to be statistically significant. Results We found a significant association between each histopathological parameters of the placenta, including fibrin deposition, maternal floor infarction, calcification, villous basement membrane thickening, and syncytial knots, and clinical diagnosis of pre-eclampsia, eclampsia, and control groups. A median score of 2 significantly correlated with the normal group, while median scores of 4 and 6 correlated with pre-eclampsia and eclampsia respectively. Conclusion This comprehensive scoring system can be a basis for validating reporting patterns of the placenta in pre-eclampsia and eclampsia patients, as well as other disorders related to maternal uteroplacental insufficiency.

A Rare Case of Round Cell Sarcoma with CIC-DUX4 Mutation Mimicking a Phlegmon: Review of Literature.

BACKGROUND Undifferentiated small blue round cell sarcomas with CIC-DUX4 translocation differ morphologically and in clinical outcomes from other types of sarcoma. Although classified by the World Health Organization as undifferentiated sarcomas, it is unclear whether these tumors are variants of Ewing's sarcoma or a distinct entity. This report describes a round cell sarcoma with CIC-DUX4 translocation that presented clinically as a phlegmon. CASE REPORT A 31-year-old African American man presented with a mass in the right upper abdominal quadrant. Examination at a local hospital suggested an intra-abdominal abscess, and incision and drainage were performed. One week later, he returned with increased pain and bloody drainage from the incision site. Computed tomography showed a complex solid-cystic area measuring 7.8 cm suggesting a large phlegmon/abscess or neoplasm. Histologically, the sarcomatous malignancy was cellular, multinodular, and necrotic, with cells having round-ovoid to spindled nuclei and variable amounts of pale cytoplasm. Immunohistochemically, the mass was focally positive for CD99, but much less positive than an Ewing sarcoma. The mass also showed diffuse nuclear positivity for WT-1 and ETV4, but was negative for desmin. Fluorescence in-situ hybridization showed positivity for CIC-DUX4 gene fusion, resulting in a final diagnosis of round cell sarcoma with CIC-DUX4 translocation. The patient has completed 14 cycles of chemotherapy with no evidence of metastasis or local recurrence. CONCLUSIONS A round cell sarcoma with CIC-DUX4 translocation can present clinically as a phlegmon with pleomorphic morphology. Early tumor identification by molecular analysis and early initiation of treatment can improve patient prognosis.