Lung transplantation for patients with severe COVID-19.

Lung transplantation can potentially be a life-saving treatment for patients with nonresolving COVID-19-associated respiratory failure. Concerns limiting lung transplantation include recurrence of SARS-CoV-2 infection in the allograft, technical challenges imposed by viral-mediated injury to the native lung, and the potential risk for allograft infection by pathogens causing ventilator-associated pneumonia in the native lung. Additionally, the native lung might recover, resulting in long-term outcomes preferable to those of transplant. Here, we report the results of lung transplantation in three patients with nonresolving COVID-19-associated respiratory failure. We performed single-molecule fluorescence in situ hybridization (smFISH) to detect both positive and negative strands of SARS-CoV-2 RNA in explanted lung tissue from the three patients and in additional control lung tissue samples. We conducted extracellular matrix imaging and single-cell RNA sequencing on explanted lung tissue from the three patients who underwent transplantation and on warm postmortem lung biopsies from two patients who had died from COVID-19-associated pneumonia. Lungs from these five patients with prolonged COVID-19 disease were free of SARS-CoV-2 as detected by smFISH, but pathology showed extensive evidence of injury and fibrosis that resembled end-stage pulmonary fibrosis. Using machine learning, we compared single-cell RNA sequencing data from the lungs of patients with late-stage COVID-19 to that from the lungs of patients with pulmonary fibrosis and identified similarities in gene expression across cell lineages. Our findings suggest that some patients with severe COVID-19 develop fibrotic lung disease for which lung transplantation is their only option for survival.

Lung transplantation for pulmonary fibrosis secondary to severe COVID-19.

Lung transplantation can potentially be a life-saving treatment for patients with non-resolving COVID-19 acute respiratory distress syndrome. Concerns limiting transplant include recurrence of SARS-CoV-2 infection in the allograft, technical challenges imposed by viral-mediated injury to the native lung, and potential risk for allograft infection by pathogens associated with ventilator-induced pneumonia in the native lung. Additionally, the native lung might recover, resulting in long-term outcomes preferable to transplant. Here, we report the results of the first two successful lung transplantation procedures in patients with non-resolving COVID-19 associated acute respiratory distress syndrome in the United States. We performed smFISH to detect both positive and negative strands of SARS-CoV-2 RNA in the explanted lung tissue, extracellular matrix imaging using SHIELD tissue clearance, and single cell RNA-Seq on explant and warm post-mortem lung biopsies from patients who died from severe COVID-19 pneumonia. Lungs from patients with prolonged COVID-19 were free of virus but pathology showed extensive evidence of injury and fibrosis which resembled end-stage pulmonary fibrosis. Single cell RNA-Seq of the explanted native lungs from transplant and paired warm post-mortem autopsies showed similarities between late SARS-CoV-2 acute respiratory distress syndrome and irreversible end-stage pulmonary fibrosis requiring lung transplantation. There was no recurrence of SARS-CoV-2 or pathogens associated with pre-transplant ventilator associated pneumonias following transplantation in either patient. Our findings suggest that some patients with severe COVID-19 develop fibrotic lung disease for which lung transplantation is the only option for survival. SINGLE SENTENCE SUMMARY: Some patients with severe COVID-19 develop end-stage pulmonary fibrosis for which lung transplantation may be the only treatment.

The diagnostic utility of PRAME and p16 in distinguishing nodal nevi from nodal metastatic melanoma.

The status of the sentinel lymph node is the strongest predictor of recurrence in patients with malignant melanoma, making accurate distinction between nodal metastases and nodal nevi of paramount importance. We explored the utility of p16 and PRAME in differentiating nodal nevi from metastatic melanoma by immunohistochemistry. We searched our institutional database for cases of nodal nevi and nodal metastatic melanoma. p16 and PRAME expression were assessed with immunolabeling quantified by extent of nuclear positivity (0-25 %, >25 %-50 %, >50 %-75 % and >75 %). Sensitivities and specificities were calculated, and discrimination assessed using the area under the receiver operating characteristic curve (AUC). Forty-nine cases out of 51 nevi and 56/56 melanoma cases had lesional tissue present for p16, while 44/51 nevi and 54/56 melanoma cases had lesional tissue present for PRAME. 43 nodal nevi (88 %) had >50 % nuclear staining for p16, while none had >50 % staining for PRAME. More than half (55 %) of melanoma cases had complete loss of nuclear staining for p16, while majority (94 %) had >50 % nuclear staining for PRAME. Using a cut-off value of 50 %, higher PRAME expression had a sensitivity and specificity of 94 % and 100 %, respectively, while lower p16 expression had a sensitivity and specificity of 66 % and 88 %, respectively, for detecting metastatic melanoma. PRAME showed significantly better discrimination (AUC = 0.97, 95 % CI 0.94-1.00) than p16 (AUC = 0.77, 95 % CI 0.68-0.86) for differentiating nodal nevi from nodal melanoma (P < 0.001). Our findings suggest that PRAME is more accurate than p16 in discriminating between the two entities, with excellent sensitivity and specificity.

Delivery of Immunotherapeutic Nanoparticles to Tumors via Enzyme-Directed Assembly.

Amphiphilic diblock copolymers are prepared by ring opening metathesis polymerization, with one block containing hydrophobic Toll-like receptor 7 (TLR7) agonists and one block containing hydrophilic peptides as substrates for matrix metalloproteinases (MMPs). A fluorescent label is incorporated into the polymer chains for in vivo imaging. Upon dialysis against aqueous solution, polymers form 15 nm spherical micelles. Subsequent exposure to MMP-9 elicits a morphological change to yield immunostimulatory microscale assemblies. The intravenous (IV) administration of the formulation to mice bearing 4T1 breast cancer tumors results in nanoparticle accumulation in tumors, reduction in primary tumor growth, and inhibition of lung metastases, as compared to saline-treated animals. Mice administered the parent immunotherapeutic small molecule (1V209) experience significantly increased plasma levels of proinflammatory cytokines IL-6, IP-10, and MCP-1 at 2 h following IV administration, whereas the nanomaterial shows no increase over saline-treated controls. These data suggest that covalently packaging low molecular weight immunotherapeutics at high weight percent loadings in enzyme-responsive nanoparticles maintains drug efficacy while decreasing immunotoxicity, providing a platform for cancer immunotherapeutic delivery.

Single-Cell Transcriptomic Analysis of Human Lung Provides Insights into the Pathobiology of Pulmonary Fibrosis.

Rationale: The contributions of diverse cell populations in the human lung to pulmonary fibrosis pathogenesis are poorly understood. Single-cell RNA sequencing can reveal changes within individual cell populations during pulmonary fibrosis that are important for disease pathogenesis. Objectives: To determine whether single-cell RNA sequencing can reveal disease-related heterogeneity within alveolar macrophages, epithelial cells, or other cell types in lung tissue from subjects with pulmonary fibrosis compared with control subjects. Methods: We performed single-cell RNA sequencing on lung tissue obtained from eight transplant donors and eight recipients with pulmonary fibrosis and on one bronchoscopic cryobiospy sample from a patient with idiopathic pulmonary fibrosis. We validated these data using in situ RNA hybridization, immunohistochemistry, and bulk RNA-sequencing on flow-sorted cells from 22 additional subjects. Measurements and Main Results: We identified a distinct, novel population of profibrotic alveolar macrophages exclusively in patients with fibrosis. Within epithelial cells, the expression of genes involved in Wnt secretion and response was restricted to nonoverlapping cells. We identified rare cell populations including airway stem cells and senescent cells emerging during pulmonary fibrosis. We developed a web-based tool to explore these data. Conclusions: We generated a single-cell atlas of pulmonary fibrosis. Using this atlas, we demonstrated heterogeneity within alveolar macrophages and epithelial cells from subjects with pulmonary fibrosis. These results support the feasibility of discovery-based approaches using next-generation sequencing technologies to identify signaling pathways for targeting in the development of personalized therapies for patients with pulmonary fibrosis.

Surgical Treatment of Multifocal Pulmonary Mucormycosis.

Mucormycosis is a devastating opportunistic fungal infection to which the immunosuppressed are particularly vulnerable. We report the case of a 60-year-old man who was found to have multifocal pulmonary mucormycosis 10 weeks after concomitant heart and kidney transplantation. Despite appropriate antifungal therapy, the infection progressed rapidly and soon involved critical pulmonary vasculature. He successfully underwent staged operative resection of his pulmonary mucormycosis without recurrence of infection. Although surgical debridement of pulmonary mucormycosis is typically reserved for localized disease, this case demonstrates that surgical intervention should be considered as an adjunct to antifungal therapy in multifocal disease.

Ectopic pleural thymoma in a 49-year-old woman: A case report.

Ectopic pleural thymoma is an exceedingly uncommon clinical entity that has only been described sporadically. Because of their peculiar location and variety of histologic patterns manifested, pleural thymomas may be confused with other neoplasms and may cause diagnostic problems clinically, radiologically, and morphologically. We describe the case of a giant left-sided ectopic pleural thymoma, preoperatively suspected to be a solitary fibrous tumor. A complete surgical resection was achieved and a postoperative diagnosis of WHO Type AB, modified Masaoka stage I tumor was attained. Subsequent thymectomy demonstrated unremarkable thymic tissue. The possibility of ectopic thymoma should be considered when the morphology of the lesion reveals a dual population of epithelial cells without significant nuclear atypia and lymphoid cells. Immunohistochemical studies are helpful in supporting the morphologic impression, both by characterizing the epithelial component as thymic in origin and by demonstrating the immature T-cell phenotype of the admixed reactive lymphocytes.

Plexiform fibromyxoma with cotyledon-like serosal growth: A case report of a rare gastric tumor and review of the literature.

Plexiform fibromyxoma is a rare, benign mesenchymal neoplasm that predilects the gastric antrum and has potential for misdiagnosis as a gastrointestinal stromal tumor (GIST). The histology of the tumor is characterized by interwoven fascicular growth of cytologically bland spindled cells within a variably myxoid stroma. The current study reports the clinicopathological and immunohistochemical findings of a plexiform fibromyxoma resected from a 28-year-old Vietnamese female. The patient presented with acute, severe abdominal pain and worsening anemia. The initial fine-needle aspiration and needle core biopsy of the gastric antral mass led to an initial diagnosis of GIST. The subsequent distal partial gastrectomy revealed a 5.5-cm transmural antral mass that ulcerated the overlying mucosa and grew as variably elongated, myxoedematous, polypoid (cotyledon-like) excrescences from the serosal surface. Microscopically, the tumor demonstrated plexiform and multinodular growth of cytologically bland spindled cells proliferating in an abundant myxocollagenous stroma with a prominent capillary network. Tumor cells immunohistochemically expressed smooth muscle actin and CD10, but did not express CD117, Discovered on GIST-1 or nuclear ß-catenin. Follow-up evaluation 23 months post surgery revealed no evidence of residual tumor. A review the cases of this rare entity reported in the English language literature is also provided.

Correlation of EGFR mutation status with predominant histologic subtype of adenocarcinoma according to the new lung adenocarcinoma classification of the International Association for the Study of Lung Cancer/American Thoracic Society/European Respiratory Society.

CONTEXT: Epidermal growth factor receptor (EGFR) mutations have been identified as predictors of response to EGFR tyrosine kinase inhibitors in non-small cell lung cancer. OBJECTIVE: To investigate the relationship of EGFR mutation status to the histologic subtype of adenocarcinoma according to the new International Association for the Study of Lung Cancer (IASLC)/American Thoracic Society (ATS)/European Respiratory Society (ERS) classification. DESIGN: We screened EGFR mutation in 200 consecutive lung adenocarcinoma resection specimens diagnosed between 2008 and 2011. RESULTS: Among 200 lung adenocarcinomas, EGFR mutations were identified in 41 tumors (20.5%). The mean age in the EGFR-mutant group was 64.8 years and this group consisted of 78% females and 22% males. Most patients with EGFR-positive lung cancers were never-smokers (51%) as compared to 8% with EGFR-negative cancers (P < .001). The most common mutations identified in our population were deletions in exon 19 (22 patients) and L858R in exon 21 (12 patients). Five patients had double mutations. The predominant pattern of adenocarcinoma was lepidic (44%) in EGFR-mutant lung cancers as compared to 69% with acinar pattern in EGFR wild-type lung cancers (P < .001). Of 22 minimally invasive adenocarcinomas, 8 (36%) had EGFR mutations, accounting for 20% of adenocarcinomas with EGFR mutations (P < .05). CONCLUSIONS: Based on the new IASLC/ATS/ERS classification, the predominant subtype of adenocarcinoma was lepidic (44%) in EGFR-mutant lung cancers (P < .001). However, histologic subtype should not be used to exclude patients from tyrosine kinase inhibitor therapy, since EGFR mutations are found in lung adenocarcinomas of other subtypes.

Sarcomatoid (spindle cell) carcinoma of the pancreas: A case report and review of the literature.

Sarcomatoid (spindle cell) carcinoma of the pancreas is a rare, high-grade epithelial malignancy composed predominantly or exclusively of spindle cells demonstrating evidence of epithelial derivation, but no features indicative of a specific line of mesenchymal differentiation. The current study presents the case of an 85-year-old Caucasian male with a tumor mass in the body of the pancreas. The individual subsequently underwent a distal pancreatectomy, splenectomy and partial gastrectomy. Microscopic examination of the 3.3-cm mass located in the body of the pancreas revealed a small, but high-grade, adenocarcinomatous component that blended imperceptibly with malignant spindle cells. No light microscopic or immunohistochemical evidence of specific mesenchymal differentiation was identified, and the spindle cells, as in the case of the carcinoma, were diffusely keratin-positive. Sarcomatoid (spindle cell) carcinoma defined in this way rarely presents in the pancreas, with, to the best of our knowledge, only six cases reported in the English literature.

Carbonic anhydrase IX is expressed in mesothelioma and metastatic clear cell renal cell carcinoma of the lung.

High immunohistochemical expression of carbonic anhydrase IX (CAIX) is found in clear cell renal cell carcinoma (ccRCC), but no studies have assessed CAIX in metastatic ccRCC (mccRCC) of the lung. As 75% of patients with mccRCC show lung involvement, characterization of protein expression in these lesions is warranted. This investigation analyzed CAIX immunohistochemical expression in pulmonary/pleural tumors including mccRCC (n = 22), mesothelioma (n = 19), squamous cell carcinoma (n = 27), small cell carcinoma (n = 9), and adenocarcinoma (n = 49), as well as other mesothelial lesions (n = 4). Membranous immunoreactivity was semiquantitatively evaluated for percent of cells stained and intensity. All cases of mccRCC (1+, 4.5%; 3+, 95.5%) and mesothelioma (2+, 10.5%; 3+, 89.5%) expressed CAIX. Most cases of lung squamous cell carcinoma (0, 11.1%; 1+, 25.9%; 2+, 22.2%; 3+, 40.7%) and small cell carcinoma were reactive (0, 11.1%; 1+, 22.2%; 2+, 33.3%; 3+, 33.3%), while CAIX was detected less frequently in pulmonary adenocarcinoma (0, 61.2%; 1+, 16.3%; 2+, 12.2%; 3+, 10.2%). In addition, CAIX was positive in adenomatoid tumor (3+, 100%) and mesothelial hyperplasia (3+, 100%). We demonstrate that CAIX is sensitive for mccRCC within the lung and a novel immunohistochemical marker for mesothelial proliferations, notably mesothelioma. Variable immunoreactivity is present among primary pulmonary epithelial tumors. Knowledge of expression overlap between these entities may prevent an incorrect interpretation of immunohistochemical results, particularly when limited tissue is available. As new carbonic anhydrase inhibitors are being evaluated, testing additional tumors for CAIX may lead to novel treatment options.

Renal medullary-like carcinoma in an adult without sickle cell hemoglobinopathy.

BACKGROUND: A 42-year-old white man with no significant prior medical history presented with macroscopic hematuria of 2 months' duration. His family history was notable for a maternal grandfather with kidney cancer. INVESTIGATIONS: Urinalysis, CT, microscopic examination of tumor, immunohistochemical analysis of tumor, hemoglobin electrophoresis, molecular cytogenetic analysis, gene sequencing. DIAGNOSIS: Renal medullary-like carcinoma in an adult without sickle cell trait, sickle cell disease or other hemoglobinopathies. MANAGEMENT: The patient underwent laparoscopic nephrectomy to remove the tumor and received adjuvant sorafenib (400 mg per day) as part of the E2805 ASSURE (Adjuvant Sorafenib or Sunitinib for Unfavorable Renal Carcinoma) trial. Metastatic recurrence of the tumor occurred 9 months after nephrectomy, for which the patient underwent tumor debulking and retroperitoneal lymph node dissection, followed by chemotherapy consisting of gemcitabine (2,000 mg/m(2)) and doxorubicin (50 mg/m(2)), both given on day 1 of a 14-day cycle. After six cycles of drug treatment, the patient had achieved a partial response. The patient was managed by active surveillance for 4 months, when he developed further symptoms and disease progression was detected. Third-line systemic therapy in the form of 21-day cycles of cisplatin (80 mg/m(2) on day 1) and etoposide (100 mg/m(2) on days 1-3) has recently been initiated.

Paracortical axillary sentinel lymph node ectopic breast tissue.

Benign glandular inclusions in axillary lymph nodes are uncommon, and their presence in axillary sentinel lymph nodes is exceptionally rare. The possibility of over-staging due to misinterpretation of glandular inclusions as metastatic carcinoma is a concerning issue. We present a 54-year-old female with high grade ductal carcinoma in-situ undergoing simple mastectomy with sentinel lymph node biopsy. Permanent sections of the sentinel lymph node revealed scarce naked small glands without surrounding stroma scattered in the paracortex in the superficial level. Deeper levels showed glands spanning a much larger area (2mm), with bland ducts and tubules separated by abundant stroma. The myoepithelial layer was visible and was immunohistochemically confirmed. A final diagnosis of benign ectopic breast tissue within an axillary sentinel lymph node was rendered. Previous studies described axillary sentinel lymph nodes with glandular inclusions separated by stroma or subcapsular in location. It has been suggested that paracortical location and absence of stroma are characteristics of metastasis. As demonstrated in our report, benign inclusions may be paracortical and lack surrounding stroma. We recommend that glandular inclusions should be a diagnostic consideration for cases in which paracortically located naked glands do not histologically resemble the corresponding primary tumor.

Fatal adenovirus pneumonia in a person with AIDS and Burkitt lymphoma: a case report and review of the literature.

Although adenoviruses are a recognized cause of serious pulmonary and disseminated disease among stem cell transplant recipients, their importance in other immunocompromised patient populations is less clearly documented. We present a case of a person with AIDS who was receiving chemotherapy for Burkitt lymphoma in whom fatal adenovirus pneumonia and adenoviremia developed, and we review the published literature on adenovirus infection in the setting of HIV disease.

Cytologic and histologic findings in multiple renal hybrid oncocytic tumors in a patient with Birt-Hogg-Dubé syndrome: a case report.

BACKGROUND: Birt-Hogg-Dubé (BHD) syndrome is a rare autosomal dominant neoplastic syndrome characterized by multiple skin lesions, lung cysts and renal tumors. A variety of histologic types of renal tumors have been reported, including clear cell renal cell carcinoma (RCC), papillary RCC, chromophobe RCC, oncocytoma and a recently described hybrid oncocytic tumor, which is thought to be highly associated with BHD. CASE: We report a case of a 48-year-old woman with BHD who initially presented to our institution with spontaneous pneumothorax and was found to have multiple lung cysts and renal tumors on computed tomography. We describe the fine needle aspiration findings of one of the renal tumors, which was suggestive of so-called hybrid oncocytic tumor. We also describe the gross and histologic findings of the multiple kidney tumors that the patient subsequently had excised. CONCLUSION: When multiple kidney tumors from a single patient appear oncycytic on fine needle aspiration, especially when focal clear cells are present, the possibility of oncocytomas and hybrid tumors associated with BHD must be entertained.

Benign metastasizing leiomyoma: clonality, telomere length and clinicopathologic analysis.

Benign metastasizing leiomyoma is a rare condition affecting women with a history of uterine leiomyomata and is characterized by multiple histologically benign pulmonary smooth muscle tumors. Speculations on its pathogenesis include a benign uterine leiomyoma colonizing the lung, a metastatic low-grade uterine leiomyosarcoma, and primary pulmonary leiomyomatosis. To elucidate its pathogenesis, we analyzed the clinical, pathological and immunohistochemical features, clonality, and telomere length of multiple lung and uterine tumors in three patients with benign metastasizing leiomyoma. In all cases, pulmonary tumors had benign histology and immunohistochemical profiles (estrogen receptor positive, progesterone receptor positive, and very low proliferative index) identical to uterine leiomyoma. In eight tumors from three patients, clonality was assessed by analyzing the variable length of the polymorphic CAG repeat sequence within the human androgen receptor gene. In the two informative patients pulmonary and uterine tumors showed identical patterns of androgen receptor allelic inactivation, indicating that they were clonal. The telomere length measured by fluorescence in situ hybridization in pulmonary leiomyomas of all three patients were either long or very long and were identical to the uterine counterparts, indicating significant telomere shortening is not a crucial step for developing metastases. Our evidence supports the notion that benign metastasizing leiomyoma is clonally derived from benign-appearing uterine leiomyomas.