Diffuse Idiopathic Pulmonary Neuroendocrine Cell Hyperplasia: A Blanked Out Pulmonary Neuroendocrine Tumor.

Introduction: Lung neuroendocrine tumors (NETs) are a rare type of pulmonary tumor and represent approximately 2% of all lung cancers. The prevalence of lung NETs is increasing, which may be due to improved diagnostic techniques for asymptomatic tumors. Diffuse idiopathic pulmonary neuroendocrine cell hyperplasia (DIPNECH) is a rare and underdiagnosed disease that falls under the spectrum of NETs. Case Presentation: We presented a case of a 59-year-old male who presented with severe coughing spells, flushing, and diarrhea. His computed tomography scan showed innumerable pulmonary nodules and irregular nodular opacities throughout the lungs. He underwent a left upper lobe wedge resection and was eventually diagnosed with neuroendocrine tumorlets via immunohistochemical stains. He was started on a trial of octreotide and reported significant improvement in symptoms after 1 month. Conclusion: DIPNECH is a rare preinvasive lesion characterized by the abnormal proliferation of pulmonary neuroendocrine cells. Patients with DIPNECH can present initially with respiratory symptoms, while other cases are discovered incidentally during the workup of different conditions. Definitive diagnosis of DIPNECH requires histopathological examination of lung tissue. There is limited evidence on DIPNECH management, and an individualized approach is currently advised.

AKR1B10 as a Potential Novel Serum Biomarker for Breast Cancer: A Pilot Study.

Background: Aldo-keto reductase 1B10 (AKR1B10) is a secretory protein that is upregulated in breast cancer. Objective: This case-controlled pilot study evaluated the serum level of AKR1B10 in healthy women and patients with a localized or metastatic breast cancer. Methods: AKR1B10 levels were measured by ELISA and IHC in several patient cohorts. Results: Our data showed that serum AKR1B10 was significantly elevated in patients with localized (6.72 ± 0.92 ng/ml) or metastatic (7.79 ± 1.13 ng/ml) disease compared to cancer-free healthy women (1.69 ± 0.17 ng/ml) (p<0.001); the serum AKR1B10 was correlated with its expression in tumor tissues, but not with the tumor burden, molecular subtypes or histological stages. After surgical removal of primary tumors, the serum AKR1B10 was rapidly decreased within 3 days and plateaued at a level similar to that of healthy controls in most patients. ROC curve analysis suggested the optimal diagnostic cut-off value of serum AKR1B10 at 3.456 ng/ml with AUC 0.9045 ± 0.0337 (95% CI 0.8384 - 0.9706), sensitivity 84.75% (95% CI 73.01% to 92.78%), and specificity 93.88% (95% CI 83.13% to 98.72%). Conclusions: These data indicate the potential value of serum AKR1B10 as a biomarker of breast cancer.

Doxycycline-induced acquired haemophilia A.

An 80-year-old man with no personal or family history of bleeding, presented to hospital with extensive haematomas and skin bruising after using doxycycline. His basic lab workup was concerning for a coagulopathy with an elevated activated partial thromboplastin time and significant anaemia. Mixing studies and other factor levels were tested that led to the diagnosis of acquired haemophilia A with low factor VIII levels and high factor VIII antibodies. He was started on steroids, but his haemoglobin level continued to drop. Later, during his treatment, he was given multiple therapeutic agents, including cyclophosphamide, rituximab and recombinant factor VII (NovoSeven-R). Gradually factor VIII levels increased and haemoglobin stabilised. The hospital course was complicated by COVID-19 pneumonia leading to acute respiratory distress syndrome; the patient eventually expired due to respiratory failure.

Renal Mucosa-Associated Lymphoid Tissue (MALT) Associated End-Stage Renal Disease in a Patient Presenting With Diarrhea.

Extranodal marginal zone lymphoma (MZL) of mucosa-associated lymphoid tissue (MALT) is most commonly found in the GI tract. Other less common anatomical sites for MALT include the skin, intestine, salivary glands, lungs, and ocular adnexa. Isolated MALT of the kidney has only been sporadically reported. Most of the reported cases in the literature present with underlying renal mass and are generally diagnosed post nephrectomy. We present a case of a 73-year-old gentleman with biopsy-proven primary MALT of the kidney who presented with acute kidney injury (AKI) in the background of Clostridium difficile (C. difficile) colitis. However, our patient did not have a renal mass a renal biopsy was performed due to accelerated deterioration of renal function. Due to the inherent heterogeneity of the disease, it is challenging to have a unifying treatment strategy for MALT with treatment varying with the anatomical site. We also discuss current and prospective treatment strategies for MALT and marginal zone lymphoma in general.

Isoniazid Induced Pure Red Blood Cell Aplasia.

Pure red blood cell aplasia (PRCA) is one of the uncommon causes of anemia. Drug-induced PRCA is even more infrequent. Only a few drugs are implicated in PRCA. Isoniazid is a widely used drug for the treatment of tuberculosis all over the world. It is known to cause hepatotoxicity, but in rare instances, it can lead to PRCA.  A 72-year-old Caucasian male, who was started on isoniazid after the diagnosis of latent tuberculosis, presented two months later with episodes of syncope to primary care physician's office. The initial blood work showed severe anemia. There were no signs of acute or chronic gastrointestinal blood loss, and the stool hemoccult test was negative. Iron, vitamin B12, folate, lactate dehydrogenase, bilirubin, transaminases, and erythropoietin were within normal limits. Peripheral blood smear showed normochromic and normocytic anemia. A reticulocyte count was less than 1,000 per microliter. Thymoma, human immunodeficiency virus, and parvovirus B19 were ruled out. Further work-up with bone marrow biopsy confirmed pure red blood cell aplasia. A detailed review of recently started medications revealed isoniazid as the offending drug. Isoniazid was stopped. Reticulocyte count and bone marrow recovered a few days after stopping with eventual improvement in hemoglobin level, thus confirming the diagnosis of isoniazid induced red blood cell aplasia. Isoniazid is the first-line therapy for tuberculosis. Rarely, it can cause pure red blood cell suppression and severe anemia, an untoward effect, worth remembering.

Whistling Lipoma: Bronchial Obstruction Caused by a Lipoma.

Lipomas are extremely common benign tumors that occur in a variety of locations. However, lipomas in the bronchus are exceptionally rare and account for a very small number of all bronchial tumors. Diagnosis of an endobronchial lipoma can be challenging at times, as they may present with overlapping symptoms of central airway obstruction, pneumonia, or dyspnea. We present an 82-year-old male with a 40-pack-year history of smoking who presented with recurrent pneumonia and signs of airway obstruction. Imaging studies showed an obstructive lesion. The biopsy sample revealed adipose cells. Eventually, the lesion was successfully resected. The surgical specimen ruled out malignancy and confirmed the diagnosis of lipoma. Timely identification and differentiating a malignant lesion from benign lesions, like lipoma, is crucial to management.