A case of hypereosinophilic syndrome with STAT5b N642H mutation.

Hypereosinophilia is defined as persistent eosinophilia (>1.5 × 109/L). Hypereosinophilic syndrome (HES) is a term used to describe a group of disorders characterized by sustained hypereosinophilia associated with end-organ damage. Based on underlying molecular mechanism of eosinophilia, there are different subtypes of HES. Diagnosis of HES subtype can be challenging, especially in the absence of overt lymphoid/myeloid neoplasms or discernable secondary causes. Long-term outpatient follow-up with periodic complete blood count and repeated bone marrow biopsy may be needed to monitor disease activity. Somatic signal transducer and activation transcription 5b (STAT5b) N642H mutation was recently found to be associated with myeloid neoplasms with eosinophilia. We report a case of HES who presented with pulmonary embolism and acute eosinophilic pneumonia, found to have recurrent STAT5b N642H mutation by next-generation sequencing, suggesting possible underlying myeloid neoplasm.

A Unique Case of Combined Nodular and Tracheobronchial Amyloidosis.

Amyloidosis is a heterogeneous group of diseases characterized by the extracellular deposition of misfolded proteins that can affect either systemically or locally confined to one system. Pulmonary amyloidosis is rare and can be classified into three forms according to the anatomic site of involvement: nodular pulmonary amyloidosis, tracheobronchial amyloidosis and diffuse alveolar-septal amyloidosis. The former two usually represent localized amyloid disease and the latter represents systemic disease. Typically lung parenchymal and tracheobronchial amyloidosis do not present together in localized forms of pulmonary amyloidosis. Here we report a unique case of localized pulmonary immunoglobulin light-chain amyloidosis, manifested as both parenchymal nodules and tracheobronchial amyloid deposition.

Mysterious quad of constrictive pericarditis, recurrent pleural effusions, bone involvement and interstitial lung disease.

Erdheim-Chester disease (ECD) is a rare multisystemic non-Langerhans cell histiocytic neoplasm. The rarity of the disease and heterogenous clinical presentations often leads to delayed diagnosis. Historically, ECD lacked effective treatment and the prognosis was poor. Following the recent discovery of frequent BRAF-V600E mutation in patients with ECD, vemurafenib, a selective BRAF V600 kinase inhibitor has been approved for BRAF-mutated ECD patients. The prognosis of ECD has dramatically improved with early recognition of the disease and available treatment. ECD affects nearly every organ system. Cardiac involvement with pericardial effusion is common but rarely with constrictive physiology or requiring pericardiectomy. We present a case of a 56-year-old woman with recurrent pericarditis with constrictive physiology along with pleural effusion and interstitial lung disease that was diagnosed with ECD 3 years after initial presentation. The patient's symptoms were relieved with pericardiectomy and targeted therapy.

Banff study of pathologic changes in lung allograft biopsy specimens with donor-specific antibodies.

BACKGROUND: The diagnosis of antibody-mediated rejection (AMR) in the lung transplant is still an area under investigation. We performed a blinded multicenter study to determine if any statistically significant histologic findings in transbronchial biopsy specimens from lung transplant patients correlate with the presence of donor-specific antibodies (DSAs). METHODS: We asked 9 pathologists with experience in lung transplantation to evaluate 161 lung transplant biopsy specimens for various histologic parameters. The findings were correlated with antibody status positive for DSAs, positive for non-DSAs, and no antibodies (NABs) present. The significance of each histologic variable was reviewed. RESULTS: We found no statistically significant association with acute cellular rejection, airway inflammation, or bronchiolitis obliterans and the presence or absence of antibodies. However, biopsy specimens with DSAs had a statistically significant difference vs NABs in the setting of acute lung injury, with or without diffuse alveolar damage (p = 0.0008), in the presence of capillary neutrophilic inflammation (p = 0.0014), and in samples with endotheliitis (p = 0.0155). In samples with complement 4d staining, there was a trend but no statistically significant difference between specimens associated with DSAs and specimens with NABs. CONCLUSIONS: Capillary inflammation, acute lung injury, and endotheliitis significantly correlated with DSAs. The infrequently observed diffuse staining for complement 4d limits the usefulness of this stain.