Pneumocystis jirovecii genotypes and granulomatous pneumocystosis

High-resolution CT findings of pulmonary infections in patients with hematologic malignancy: comparison between patients with or without hematopoietic stem cell transplantation

Purpose

To evaluate the high-resolution CT (HRCT) findings of pulmonary infections in patients with hematologic malignancy and compare them between patients with or without hematopoietic stem cell transplantation (HSCT).

Materials and methods

A total of 128 patients with hematologic malignancy and pulmonary infection were included in this study. The diagnoses of the patients consisted of bacterial pneumonia (37 non-HSCT cases and 14 HSCT cases), pneumocystis pneumonia (PCP) (29 non-HSCT cases and 11 HSCT cases), and fungal infection other than PCP (20 non-HSCT cases and 17 HSCT cases). Two chest radiologists retrospectively evaluated the HRCT criteria and compared them using chi-squared tests and a multiple logistic regression analysis.

Results

According to the multiple logistic regression analysis, nodules were an indicator in HSCT patients with PCP (p = 0.025; odds ratio, 5.8; 95% confidence interval, 1.2–26.6). The centrilobular distribution of nodules was the most frequent (n = 4, 36%) in HSCT patients with PCP. A mosaic pattern was an indicator of PCP in both HSCT and non-HSCT patients. There were no significant differences in other infections.

Conclusion

The mosaic pattern could be an indicator of PCP in both HSCT and non-HSCT patients. Nodules with centrilobular distribution might be relatively frequent HRCT findings of PCP in HSCT patients.

Multiple Mass Lesions in Pneumocystis Pneumonia

We encountered a case of pneumocystis pneumonia (PCP) presenting with multiple mass lesions in a human immunodeficiency virus (HIV)-negative patient. Diagnosis of PCP before bronchoscopy was difficult because chest computed tomography (CT) findings were atypical of PCP and a serum (1,3)-β-D-glucan concentration was within normal limits. Bronchoscopic biopsy and Grocott’s staining enabled the diagnosis of PCP. PCP can show various patterns on chest CT images, depending on the immune status of the host. In high-risk patients, such as those who are immunocompromised, bronchoscopy should be performed with suspected cases of PCP, even if CT imaging does not show typical ground-glass opacity.

Atypical Presentation of Pneumocystis jirovecii Infection in HIV Infected Patients: Three Different Manifestations

Advances in the treatment and prevention of Pneumocystis jirovecii infection (PJI) in human immunodeficiency virus (HIV) patients decreased incidence and mortality dramatically, however, it may be associated with an increased frequency of unusual manifestation such as cystic formation, pneumothorax, focal infiltration, nodular formation, or extrapulmonary lesions. We report three cases of PJI with atypical manifestations. Each case demonstrates different clinical features: multiple nodular pulmonary lesion (32-year-old man with abnormal chest X-ray finding), subpleural mass-like lesion (43-year-old man with left visual loss and right pleuritic chest pain), and extrapulmonary mass-like lesions in the liver, lymph nodes, and small bowel (39-year-old man with cough, sputum, and dyspnea). P. jirovecii was confirmed in all 3 cases and they were treated well. It is necessary to understand that PJI shows variable clinical features.

PJP granuloma in an Immune competent host: Case report and literature review

PJP (Pneumocystis jirovecii) is a fungal agent by taxonomy. Ones considered a protozoan, it is now recognized as fungi based on ribosomal RNA and other gene sequence homologies, the composition of their cell walls, and structure of key enzymes. This organism generally affects immunocompromised hosts with a CD4 count <200 or <15%.Review of literature does support a rare occurrence of PJP infections in immunocompetent hosts.PJP can occur at normal CD 4 levels.

Pneumocystis Pneumonia Presenting as an Enlarging Solitary Pulmonary Nodule

Pneumocystis pneumonia is a life threatening infection that usually presents with diffuse bilateral ground-glass infiltrates in immunocompromised patients. We report a case of a single nodular granulomatous Pneumocystis pneumonia in a male with diffuse large B-cell lymphoma after R-CHOP therapy. He presented with symptoms of productive cough, dyspnea, and right-sided pleuritic chest pain that failed to resolve despite treatment with multiple antibiotics. Chest X-ray revealed right lower lobe atelectasis and CT of chest showed development of 2 cm nodular opacity with ground-glass opacities. Patient underwent bronchoscopy and biopsy that revealed granulomatous inflammation in a background of organizing pneumonia pattern with negative cultures. Respiratory symptoms resolved but the solitary nodular opacity increased in size prompting a surgical wedge resection which revealed granulomatous Pneumocystis pneumonia infection. This case is the third documented report of Pneumocystis pneumonia infection within a solitary pulmonary nodule in an individual with hematologic neoplasm. Although Pneumocystis pneumonia most commonly occurs in patients with HIV/acquired immunodeficiency syndrome and with diffuse infiltrates, the diagnosis should not be overlooked when only a solitary nodule is present.

Unmasking Granulomatous Pneumocystis jirovecii Pneumonia with Nodular Opacity in an HIV-Infected Patient after Initiation of Antiretroviral Therapy

Pneumocystis jirovecii pneumonia (PJP) in patients with HIV infection can, in rare cases, present with pulmonary nodules that histologically involve granulomatous inflammation. This report describes an intriguing case of granulomatous PJP with pulmonary nodules after commencing antiretroviral therapy (ART) in an HIV-infected patient without respiratory signs or symptoms. Diagnosis of granulomatous PJP was only achieved through thoracoscopic lung biopsy. This case suggests that granulomatous PJP should be considered in the differential diagnosis of pulmonary nodules in HIV-infected patients for unmasking immune reconstitution inflammatory syndrome manifestation after initiation of ART.

Granulomatous Reaction to Pneumocystis jirovecii Diagnosed in a Bronchoalveolar Lavage: A Case Report

BACKGROUND

Granulomatous reaction to Pneumocystis jirovecii is a rare but well-known pathological finding encountered in the setting of immunosuppression, HIV infection being the most common cause. It can also potentially complicate the treatment of hematological malignancies, typically when drugs lowering the count and function of lymphocytes are used. Lung biopsy is considered the gold standard for the diagnosis of granulomatous P. jirovecii pneumonia, whereas the diffuse alveolar form is usually detected cytologically in bronchoalveolar lavage (BAL).

CASE

A female patient pursuing R-CHOP chemotherapy for the treatment of multiple hematological malignancies developed a rapidly progressing dyspnea. Chest CT scans revealed a worsening of a known infiltrative lung disease thought to be secondary to her chemotherapy. Alterations compatible with a drug-induced interstitial lung disease and well-formed focally necrotizing granulomas were observed on an open lung biopsy, but no microorganism was identified with special stains. Eventually, a granulomatous reaction to P. jirovecii was found in a BAL and allowed appropriate treatment with rapid improvement of the dyspnea.

CONCLUSION

Because granulomas are tissue-bound structures, they are rarely described in BAL. This article describes the first reported cytological diagnosis of a granulomatous reaction to P. jirovecii and the potential diagnostic interest of such a peculiar finding.

Single nodular opacity of granulomatous pneumocystis jirovecii pneumonia in an asymptomatic lymphoma patient

The radiologic findings of a single nodule from Pneumocystis jirovecii pneumonia (PJP) have been rarely reported. We described a case of granulomatous PJP manifesting as a solitary pulmonary nodule with a halo sign in a 69-year-old woman with diffuse large B cell lymphoma during chemotherapy. The radiologic appearance of the patient suggested an infectious lesion such as angioinvasive pulmonary aspergillosis or lymphoma involvement of the lung; however, clinical manifestations were not compatible with the diseases. The nodule was confirmed as granulomatous PJP by video-assisted thoracoscopic surgery biopsy.

Granulomatous PJP presenting as a solitary lung nodule in an immune competent female

Pneumocystis jiroveci pneumonia (PJP) opportunistically targets immunosuppressed patients, most notably those with advanced HIV/AIDS. Radiologically, PJP typically appears as bilateral diffuse pulmonary infiltrates. Herein an unusual case of an immunocompetent woman developing granulomatous PJP in the absence of evident risk factors is described. PJP may be an under-recognized cause of pulmonary nodules in immune competent individuals.

Atypical Pneumocystis jiroveci pneumonia with multiple nodular granulomas after rituximab for refractory nephrotic syndrome

BACKGROUND

Rituximab, an anti-CD20 antibody that targets B cells, is a promising agent against steroid-dependent and steroid-resistant nephrotic syndrome in children.

CASE-DIAGNOSIS/TREATMENT

We report a 3-year-old boy who presented with atypical Pneumocystis jiroveci pneumonia (PCP) following administration of rituximab for refractory nephrotic syndrome. He had received cyclosporine and daily prednisolone for over 1 year. Following rituximab therapy, a hazy shadow was observed on his chest X-ray. Chest-computed tomography revealed multiple nodular lesions in bilateral lungs, although his clinical symptoms were subtle. PCR analysis demonstrated the presence of Pneumocystis DNA in his bronchoalveolar lavage. Lung wedge resection of the nodular lesion exhibited granulomas containing a few cysts of P. jiroveci that primarily consisted of T cells and histiocytes and lacked B cells. A deficiency of B cells following rituximab treatment suggests a dramatic effect on the immune response and, therefore, could result in granulomatous PCP. Nodular granulomatous lesions of PCP comprise an emerging concept previously reported in adults with hematological disease, bone marrow transplant, or treatment with rituximab. We report the first pediatric case of nodular PCP. Granulomatous PCP can be life-threatening. Moreover, bronchoalveolar lavage often fails to demonstrate the presence of P. jiroveci DNA. Wedge biopsy is warranted for definitive diagnosis. Our patient fully recovered with sulfamethoxazole/trimethoprim treatment because of early detection.

CONCLUSIONS

The indication of rituximab for refractory nephrotic syndrome has increased recently. Therefore, recognition of the risk of atypical PCP is important. Our findings suggest that PCP prophylaxis should be considered following rituximab therapy.

Detection of microorganisms in granulomas that have been formalin-fixed: review of the literature regarding use of molecular methods

Granuloma is an organized aggregate of immune cells that under the microscope appear as epithelioid macrophages. A granuloma can only be diagnosed when a pathologist observes this type of inflammation under the microscope. If a foreign body or a parasite is not observed inside the granuloma, stains for acid-fast bacilli and fungi are ordered since mycobacteria and fungi are frequently the cause of this type of inflammation. It is calculated that 12 to 36% of granulomas do not have a specific etiology and many have wondered if with new molecular methods we could reduce this number. This paper will summarize the frequently known causes of granulomas and will present the recent literature regarding the use of molecular techniques on tissue specimens and how these have helped in defining causative agents. We will also briefly describe new research regarding formation and function of granulomas and how this impacts our ability to find an etiologic agent.

Granulomatous Pneumocystis jiroveci pneumonia associated with immune reconstituted HIV

Pneumocystis jiroveci pneumonia uncommonly presents with pulmonary nodules and granulomatous inflammation. An unusual case of granulomatous P jiroveci pneumonia in an HIV patient with a CD4(+) lymphocyte count of greater than 200 cells⁄mm(3), occurring in the context of immune reconstitution with highly active antiretroviral therapy, is described. The case highlights the importance of establishing this diagnosis to institute appropriate therapy.