Pneumocystis jirovecii pneumonia presenting as a large pulmonary mass in a patient with AIDS.

Pneumocystis jirovecii pneumonia typically presents with diffuse bilateral infiltrates or ground-glass opacities. However, the radiographic pattern may be atypical. We report a case of a woman in her 40s who presented with multiple pulmonary masses and prolonged symptoms of non-productive cough, generalised weakness and fatigue. Serial chest CT performed prior to her presentation showed a large right lower lobe lung mass with multiple additional bilateral pulmonary nodules. Her workup revealed a new diagnosis of AIDS. Pathology of several CT-guided needle biopsies was consistent with Pneumocystis which was confirmed by microbial DNA sequencing. No additional pathogens were identified. Her clinical symptoms and radiographs improved significantly with trimethoprim-sulfamethoxazole and treatment of her HIV infection. Clinicians should evaluate for underlying immunodeficiency and seek infectious disease and pulmonary consultation early for consideration of alternative diagnoses when patients present with cough, dyspnoea and atypical chest radiographs, and initial pathological examination is unrevealing.

A 43-Year-Old Woman With Pleuritic Chest Pain, Shortness of Breath, and Weakness of All Extremities.

CASE PRESENTATION: A 43-year-old woman with a medical history of hypothyroidism, psoriasis, and tobacco abuse (30-pack year history) who had quit smoking several months prior to presentation presented with pleuritic chest pain. She also noted a 2-year history of progressive numbness and weakness in her bilateral upper and lower extremities that now prevented her from completing her activities of daily living. She had worsening exertional dyspnea and a subjective 50-lb weight loss over the past year.

Classical Hodgkin Lymphoma Presenting as a Sigmoid Mass.

Primary classical Hodgkin lymphoma (CHL) in the colon is exceedingly rare and shares many histologic features with other lymphoproliferative disorders in the gastrointestinal tract. Here we report a case of CHL forming a sigmoid mass. An elderly man with a past medical history of mantle cell lymphoma presented with constipation. Imaging revealed an ulcerated, circumferential mass in the sigmoid colon. Endoscopic biopsy of the mass showed ulcerated colonic mucosa with an underlying diffuse mixed inflammatory infiltrate admixed with Hodgkin and Reed-Sternberg cells. Immunohistochemistry was performed to characterize these cells. They were weakly positive for Pax-5, strongly positive for CD30, variably positive for CD15, and negative for CD45, CD20, CD3, and SOX-11. In situ hybridization was positive for Epstein-Barr virus (EBV) and negative for cytomegalovirus or herpes simplex virus. This immunophenotype is diagnostic for CHL in the clinical context of a large mass. It is not possible in this case to determine whether this is de novo CHL or progression from a precursor lesion like EBV-positive mucocutaneous ulcer. Since diagnosis, this patient underwent colectomy followed by chemotherapy and has remained in complete remission.