Atypical pituitary abscess lacking rim enhancement and diffusion restriction with an unusual organism, Moraxella catarrhalis: A case report and review of the literature

Background: Pituitary abscess (PA) can be fatal if diagnosed late. Rim enhancement is a typical radiological finding of PA on postgadolinium T1-weighted magnetic resonance imaging (MRI). Diffusion-weighted imaging is helpful in distinguishing PA from other sellar cystic lesions. Herein, we report the first atypical case of PA showing neither rim enhancement nor diffusion restriction with an unusual organism, Moraxella catarrhalis. Case Description: A 77-year-old woman presented with headache, polyuria, polydipsia, and fatigue for a month before presenting to a local hospital. MRI showed pituitary enlargement with contrast enhancement. She had neither fever nor visual deficits and was followed up with hormonal replacement. Six months later, she complained of visual impairment, and MRI showed further pituitary enlargement with a thickened stalk compressing the optic chiasma. Neither rim enhancement nor diffusion restriction was observed. Endoscopic endonasal transsphenoidal surgery was performed based on the radiological diagnosis of lymphocytic hypophysitis or pituitary tumors. A thick, creamy yellow pus was drained from the sellar lesion. Intraoperative rapid histopathological findings revealed polymorphonuclear leukocytes infiltrating the pituitary gland. PA was diagnosed, and irrigation and open drainage of the abscess was performed. Bacterial culture of the pus detected M. catarrhalis by mass spectrometer, confirming the diagnosis. She underwent appropriate antibiotic administration, and her visual deficits improved. Conclusion: We report the first atypical case of PA showing neither rim enhancement nor diffusion restriction with M. catarrhalis. Even if preoperative findings are not suggestive of PA, it should be considered as a differential diagnosis. Intraoperative rapid histopathological findings are useful for accurately diagnosing PA and initiating appropriate surgical treatment.

Coinciding SARS-CoV-2 infection in HIV patients with cerebral toxoplasma

A massive and notorious impact of coronavirus disease 2019 (COVID-19) pandemic has affected communities worldwide, urging extra preventive measure, especially for individuals with comorbidities including those who are suffering from human immunodeficiency virus/acquired immune deficiency syndrome (HIV/AIDS). We reported a case of a 45-year-old man with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and HIV infection as well as toxoplasmosis. The patient presented to the hospital with decreased consciousness and stiffness on both hands and feet accompanied with loss of appetite, fever, and coughing. Since 2014, he had been diagnosed with HIV and undergone combined antiretroviral therapies. Toxoplasmosis was revealed by multislice computed tomography (MSCT) showing multiple rim-like lesion in cortex-subcortex of left temporal lobe along with surrounding perifocal oedema. Furthermore, the finding was corroborated by the contrasted image exhibiting rim enhancement patterns. The patient was also RT-PCR confirmed Covid-19. Following examinations, the patient received pyrimethamine with a loading dose of 200 mg. The management was continued with oral intake of pyrimethamine, clindamycin, folic acid, and vitamin B6 for maintenance dose. This case report suggests that HIV patient suffering from COVID-19 can be treated with antiretroviral therapies since the specific antivirus for SARS-CoV-2 has not yet available. We believe that this case report could contribute to more understanding on the development of clinical management for COVID-19 in HIV-positive patients.

Conventional and advanced MR imaging findings in a cohort of pathology-proven dermoid cysts of the pediatric scalp and skull

Background In the pediatric population, dermoid cysts are among the most frequent lesions of the scalp and skull. Imaging plays a key role in characterizing scalp and skull lesions in order to narrow the differential diagnoses. In general, dermoids are described as heterogeneous T1-/T2-hypo- to hyperintense lesions on magnetic resonance imaging. Methods The goal of this retrospective study is to evaluate the diffusion weighted imaging findings while reviewing the conventional T1-/T2-/T1+C-weighted MR characteristics in a pathology-proven series of 14 dermoids of the pediatric scalp and skull. Results In our pediatric cohort (eight boys, six girls, age range 3–95 months), half of the dermoids were homogeneous T1-hypointense and homogeneous T2-hyperintense. We found a mixture of restricted (45.5%) and increased diffusion (54.5%) in dermoids. The vast majority of dermoids (91.7%) showed rim enhancement. Most dermoids (57.1%) were located at the midline and adjacent to one of its sutures. Conclusions This study suggests that dermoids may have more variable imaging appearances than hitherto assumed and are frequently seen in close proximity or adjacent to the anterior fontanelle.

Hypercalcaemia associated with disseminated cryptococcosis

We report an elderly man who presented with giddiness and right-sided weakness, constipation and constitutional symptoms for 6 months duration. Blood investigations indicated hypercalcaemia with normal serum phosphate and acute kidney injury. Serum intact parathyroid hormone was suppressed. CT revealed bilateral tiny lung nodules with right upper lobe tree in bud appearance and incidental findings of bilateral adrenal lesion. Tuberculosis was ruled out. CT adrenal showed multiseptated hypodense rim enhancement adrenal lesion bilaterally. Adrenal function tests were normal except for low dehydroepiandrosterone (DHEA). Right-sided cervical lymph node biopsy confirmed fungal infection with the presence of intracellular and extracellular fungal yeast. Serum cryptococcus antigen titre was positive. Our final diagnosis was disseminated cryptococcosis with lungs, bilateral adrenal gland and lymph nodes involvement. The patient was then treated with antifungal treatment. Serum calcium was normalised after 1 month with marked clinical improvement.

Rathke’s Cleft Cyst Abscess—An Unusual Guest in The Sella

Abscess formation within a Rathkes’s cleft cyst (RCC) is extremely rare, particularly at a young age. We report the case of a young girl with abscess formation in RCC. A 21-year-old female presented with headache, vomiting, visual deterioration and features suggestive of hypopituitarism. She had bitemporal hemianopia with impairment of visual acuity. MRI revealed a cystic lesion in the sella with suprasellar extension and peripheral rim enhancement. On the basis of history and imaging, this was indistinguishable from more commonly encountered pituitary pathology. She underwent transsphenoidal decompression, which revealed yellowish purulent material that when cultured grew Staphylococcus epidermidis. Histological examination revealed numerous neutrophils and cyst wall lining with features characteristic of RCC. Postoperatively, she received antibiotics and replacement therapy for hypopituitarism. Three months later, she experienced deterioration in visual fields. Considering persistent disease, she underwent redo surgery which revealed similar findings. Postsurgery, pituitary MRI revealed an empty sella syndrome. Thereafter, follow-up for 1 year was stable with permanent diabetes insipidus and multiple pituitary hormone deficiency on supplementation. Although uncommon, we recommend considering RCC abscess as a differential diagnosis of a pituitary mass lesion, as predicting its presence can be difficult preoperatively. Persistent or recurrent disease is common in these cases, so timely diagnosis and adequate surgical drainage leads to lower morbidity and mortality.

The Clinical Significance of the Hyperintense Acute Reperfusion Marker Sign in Subacute Infarction Patients

Purpose: The hyperintense acute reperfusion marker (HARM) is characterized by the delayed enhancement of the subarachnoid or subpial space observed on postcontrast fluid-attenuated inversion recovery (FLAIR) images, and is considered a cerebral reperfusion marker for various brain disorders, including infarction. In this study, we evaluated the cerebral distribution patterns of HARM for discriminating between an enhancing subacute infarction and an enhancing mass located in the cortex and subcortical white matter. Materials and methods: We analyzed consecutive patients who experienced a subacute ischemic stroke, were hospitalized, and underwent conventional brain magnetic resonance imaging including postcontrast FLAIR within 14 days from symptom onset, as well as those who had lesions corresponding to a clinical sign detected by diffusion-weighted imaging and postcontrast T1-weighted imaging between May 2019 and May 2021. A total of 199 patients were included in the study. Of them, 94 were finally included in the subacute infarction group. During the same period, 76 enhancing masses located in the cortex or subcortical white matter, which were subcategorized as metastasis, malignant glioma, and lymphoma, were analyzed. We analyzed the overall incidence of HARM in subacute ischemic stroke cases, and compared the enhancement patterns between cortical infarctions and cortical masses. Results: Among 94 patients with subacute stroke, 78 patients (83%) presented HARM, and among 76 patients with subcortical masses, 48 patients (63%) presented peripheral rim enhancement. Of 170 subcortical enhancing lesions, 88 (51.8%) showed HARM, and 78 (88.6%) were determined to be subacute infarction. Among 94 patients with subacute stroke, 48 patients (51%) had diffusion restrictions, and HARM was found in 39 patients (81.2%). Of the 46 patients (49%) without diffusion restriction, 39 patients (84.8%) showed HARM. Conclusions: The presence of HARM was significantly associated with subacute infarctions. For the masses, a peripheral rim enhancement pattern was observed around the mass rather than the cerebral sulci on postcontrast FLAIR.

Magnetic resonance imaging features of large joint tuberculous arthritis

Objectives: Large joint monoarticular tuberculous involvement is rare. It may not be associated with classical clinical features. Hence, it is difficult to differentiate from other conditions similarly involving the large joints. Our study aimed to study the characteristics of large joint monoarthritis on magnetic resonance imaging. Material and Methods: We reviewed the radiology database for large joint tubercular arthritis cases over 2 years. In total, there were 21 patients. Male: female ratio was 11:10. The mean age was 34.14 ± 15.82 years with a range of 8–57 years. We diagnosed tuberculosis (TB) based on histopathological examination or response to antitubercular therapy. Results: Knee was most frequently involved (47%; n = 10) followed by wrist and elbow in 3 patients each (14.28%). Concomitant active pulmonary TB was absent in all of our patients. Grade I synovial thickening was seen in eight patients, Grade II in four, and Grade III in seven. It was uniform in all the cases. Grade 1 bone marrow edema was seen in 06 patients, Grade III in 13, and none in 02. There was soft-tissue edema in 12 patients and soft-tissue collection in 2. Bone erosions were seen in 16 patients with rim enhancement in nine patients. Central erosions were seen in eight, while central and peripheral erosions in eight. On T1-weighted images, the signal intensity was hyperintense 10 and isointense in 11 patients. While on T2-weighted images, it was hyperintense in 10, isointense in nine, and hypointense in two patients. Conclusion: Large joint monoarticular tuberculous arthritis can present variably. Large erosions with rim enhancement, the signal intensity of synovium on T1 weighted and T2 weighted, uniformity of synovial thickening, and enhancement pattern of abscesses can help make a diagnosis.

Performance of Contrast-Enhanced Ultrasound in Thyroid Nodules: Review of Current State and Future Perspectives

Ultrasound has been established as a baseline imaging technique for thyroid nodules. The main advantage of adding CEUS is the ability to assess the sequence and intensity of vascular perfusion and hemodynamics in the thyroid nodule, thus providing real-time characterization of nodule features, considered a valuable new approach in the determination of benign vs. malignant nodules. Original studies, reviews and six meta-analyses were included in this article. A total of 624 studies were retrieved, and 107 were included in the study. As recognized for thyroid nodule malignancy risk stratification by US, for acceptable accuracy in malignancy a combination of several CEUS parameters should be applied: hypo-enhancement, heterogeneous, peripheral irregular enhancement in combination with internal enhancement patterns, and slow wash-in and wash-out curve lower than in normal thyroid tissue. In contrast, homogeneous, intense enhancement with smooth rim enhancement and “fast-in and slow-out” are indicative of the benignity of the thyroid nodule. Even though overlapping features require standardization, with further research, CEUS may achieve reliable performance in detecting or excluding thyroid cancer. It can also play an operative role in guiding ablation procedures of benign and malignant thyroid nodules and metastatic lymph nodes, and providing accurate follow-up imaging to assess treatment efficacy.

Role of multi-parametric MRI in the differentiation between mucinous breast carcinoma and fibroadenoma

Background The purpose of this study was to evaluate diagnostic performance of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and functional MRI (diffusion and MR spectroscopy) using the latest MRI breast imaging reporting and data system (MRI-BIRADS) descriptors and non-BIRADS items for differentiation of mucinous breast carcinomas from fibroadenomas. Methods We included 19 cases of mucinous breast carcinoma and 37 cases of fibroadenoma. DCE-MRI, Diffusion-weighted MR imaging (DWI) and multi-voxel MR spectroscopy (MRS) were done, MRI-BIRADS (5th edition) analysis of the lesions was performed, and histopathological examination of all cases was done. Results According to univariate analysis, mucinous carcinoma was frequently detected in older age-group (COR = 1.4, 95% CI = 1.1–1.7 and p value < 0.001) and had more frequent irregular borders and non-circumscribed margins than fibroadenoma (COR = 11.6, 95% CI = 2–66.4 and p value = 0.002). All mucinous carcinoma had high T2 signal. Fibroadenomas had more frequent homogenous enhancement than mucinous carcinoma; none of the fibroadenomas had rim enhancement nor enhancing internal septations; mucinous carcinoma had more frequent rim enhancement and (n = 6, p value < 0.001) and enhancing internal septations (n = 7, p value < 0.001). Fibroadenoma had frequent dark non-enhancing internal septations than mucinous carcinoma (p value < 0.001). On multivariate analysis, mucinous carcinoma had significant combination of being common in older age, larger in size, with irregular shape, and non-circumscribed margins. On ADC map and MRS, mucinous carcinoma had higher ADC values and higher CHO.SNR than fibroadenoma. The mean ADC value of mucinous carcinoma was 1.3 ± 0.1 × 10−3mm2/s, which was significantly higher than that of fibroadenoma (1.1 ± 0.1 × 10−3mm2/s), with p = 0.002. Also, the mean CHO.SNR was significantly higher in mucinous carcinoma (3.1 ± 0.8) than fibroadenoma (0.8 ± 0.5) with p value < 0.001. According to our results, the presence of type 3 (washout curve), dark internal septations, non-circumscribed margins and irregular shape of the lesion showed the highest sensitivity and accuracy for differentiation of mucinous carcinomas and fibroadenomas (100, 78.6%), (89.4, 82%), (86.5, 80.3%) and (81, 71.4%), respectively. Conclusion The combined use of DCE-MRI, DW-MRI and MRS with breast MRI-BIRADS descriptors and non-BIRADS items increases the diagnostic accuracy for differentiation of mucinous carcinomas from fibroadenomas.