Cryptococcus infection is an invasive fungal infection common in immunocompromised hosts, especially in organ transplant recipients and in patients with HIV. Its presentation varies from localized skin lesions to systemic disseminated infection involving the lungs and the central nervous system (CNS). We present the case of a 50-year-old woman with diabetes mellitus type 2 (DM-2), end-stage renal disease (ESRD) status post deceased donor kidney transplantation seven and a half years ago who presented with a low-grade fever, cough, nausea, vomiting, and a large cystic mass on the right foot. A CT scan of the chest showed a 14 mm cavitary lesion in the middle lobe of the right lung. Serum and cerebrospinal fluid cryptococcal antigens were detected. MRI of the right foot showed a large multilocular lobulated septated cystic mass. Histopathology showed cryptococcus; the diagnosis was made as disseminated cryptococcus infection. She was treated with antifungal therapy successfully. A large cutaneous cystic mass is a rare cutaneous presentation of cryptococcus infection; clinicians should keep it in the differential diagnosis, especially in transplant recipient patients.

UNASSIGNED: Neuroglial heterotopia is a rare lesion composed of differentiated neuroectodermal cells that manifest in extracranial locations, with the majority of cases predominantly occurring in the head and neck region. Retroperitoneal neuroglial heterotopia is exceptionally rare, with isolated cases published in the scientific literature.
UNASSIGNED: Here, we present the case of a 3-year-old girl who was admitted without clinical signs but presented with a palpable abdominal mass. Ultrasonography and computed tomography scans revealed a sizable cystic lesion within the retroperitoneal space. Subsequently, laparoscopic resection was performed. Histological examination unveiled neuroglial cell-lined cysts encompassing fibrous connective tissue, ganglia, glial tissue, and nerve bundles. Notably, distinct areas and cell types exhibited expression of S100, glial fibrillary acidic protein, and neuron-specific enolase. Follow-up assessments revealed no relapses or late complications.
UNASSIGNED: In cases of retroperitoneal neuroglial heterotopia, most children may remain asymptomatic without any congenital anomalies. Despite their detectability through imaging, accurate preoperative diagnosis is seldom achieved. Generally, a favorable prognosis follows complete surgical resection, although further cases are required to confirm its long-term efficacy, necessitating extended follow-up for verification.

OBJECTIVE: TFE3-rearranged renal cell carcinomas (RCCs) harbor gene fusions between TFE3 and 1 of many partner genes. MED15::TFE3 fusion RCC is rare, often cystic, and easily misdiagnosed.
METHODS: This study aimed to characterize 2 cases of MED15::TFE3 fusion RCC with extensive cystic change using fluorescence in situ hybridization and targeted RNA sequencing.
RESULTS: Both patients were young adult women aged 29 and 35 years. Radiologically, both presented with a cystic Bosniak category II renal lesion. The cysts measured 9.3 cm and 4.8 cm in greatest dimension. Both patients underwent cyst enucleation, and neither had tumor recurrence or metastasis at 26 and 6 months of follow-up, respectively. Microscopically, both tumors were entirely cystic, with thick, fibrous cystic walls lined by small clusters of cells with clear to eosinophilic cytoplasm and uniform, round nuclei with inconspicuous nucleoli. There were also small aggregations of similar clear cells within the cystic walls. Foci of basement membrane-like material depositions were noted in 1 case; calcifications were observed in both cases. Both cases demonstrated nuclear positivity for PAX8 and TFE3 and cytoplasmic staining for Melan-A; HMB45, CAIX, and CK7 were negative. Fluorescence in situ hybridization revealed that both tumors were positive for TFE3 rearrangements. RNA sequencing identified MED15::TFE3 gene fusions in both cases.
CONCLUSIONS: The main differential diagnosis of MED15::TFE3 fusion RCC includes multilocular cystic renal neoplasm of low malignant potential and atypical renal cysts. Molecular confirmation of TFE3 fusion is essential for establishing the correct diagnosis.

Retroperitoneal ganglioneuroma is a rare neuroectodermal tumor with a benign nature. We performed a literature review among 338 studies. We included 9 studies, whose patients underwent CT and/or MRI to characterize a retroperitoneal mass, which was confirmed to be a ganglioneuroma by histologic exam. The most common features of ganglioneuroma are considered to be a solid nature, oval/lobulated shape, and regular margins. The ganglioneuroma shows a progressive late enhancement on CT. On MRI it appears as a hypointense mass in T1W images and with a heterogeneous high-intensity in T2W. The MRI-\"whorled sign\" is described in the reviewed studies in about 80% of patients. The MRI characterization of a primitive retroperitoneal cystic mass should not exclude a cystic evolution from solid masses, and in the case of paravertebral location, the differential diagnosis algorithm should include the hypothesis of ganglioneuroma. In our case, the MRI features could have oriented towards a neurogenic nature, however, the predominantly cystic-fluid aspect and the considerable longitudinal non-invasive extension between retroperitoneal structures, misled us to a lymphatic malformation. In the literature, it is reported that the cystic presentation can be due to a degeneration of a well-known solid form while maintaining a benign character: the distinguishing malignity character is the revelation of immature cells on histological examination.

Presented are four cystic renal masses which harbored a MED15::TFE3 gene fusion detected by RNAseq, mimicking multilocular cystic neoplasm of low malignant potential. Clinicopathologic and outcomes data were collected for all cases. Radiologically, three cases were diagnosed as complex cystic masses and one case as a renal cyst, three years prior to surgery. The tumors ranged in size from 1.8 to 14.5 cm. Grossly, all masses were extensively cystic. Microscopically, cells with a clear or minimally granular cytoplasm and nuclei with inconspicuous nucleoli lined the cysts\' septa. Focally, small mass-forming aggregates of malignant cells were present between septae and were associated with psammomatous calcifications. In case one, apparent prior cyst wall rupture was associated with reactive changes and cystic spaces filled with fibrin clots. Two of the tumors were staged as T1a, one as T1b, and the other as T2b. By immunohistochemistry, the tumors were positive for TFE3, MelanA, and P504S, with apical CD10 while CAIX and CK7 were negative. RNA sequencing was performed on all cases revealing a MED15::TFE3 gene fusion. The patients were alive and without evidence of disease 11-49 months (mean 29.5) after partial nephrectomy. To date, 12 of the 15 MED15::TFE3 fusion renal cell carcinomas published in the literature are cystic, with three being extensively cystic. Thus, if a multilocular cystic renal neoplasm is encountered in a kidney specimen, translocation renal cell carcinoma should be included in the differential diagnosis as cystic MED15::TFE3 tRCCs carry an uncertain prognosis making recognition for future characterization necessary.

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A meconium pseudocyst is formed following meconium peritonitis. At present, antenatal diagnosis and planned management of meconium pseudocyst have reduced the mortality rate significantly. We presented a case of a neonate with abdominal distension and non-passage of meconium who experienced respiratory distress and was taken for exploratory laparotomy at a tertiary care center due to suspected bowel perforation. The neonate was diagnosed with a meconium pseudocyst intraoperatively as maternal ultrasound and ultrasound of the abdomen of the neonate after birth failed to make a definitive diagnosis; even an X-ray abdomen did not reveal pathognomonic egg-shell calcification. An interesting aspect of this case is the mother\'s complex obstetric history, which compelled us to conjecture whether it was possible to predict the chances of meconium peritonitis and take steps to prevent it. It must be noted that, despite rigorous research, the researchers could not find reliable literature co-relating the obstetric history of the mother with the formation of a meconium pseudocyst in the neonate.

As the majority of incidentally detected lesions in the anterior mediastinum is small nodules with soft tissue appearance, the differential diagnosis has typically included thymic neoplasm and prevascular lymph node, with benign cyst. Overestimation or misinterpretation of these lesions can lead to unnecessary surgery for ultimately benign conditions. nonsurgical anterior mediastinal lesions. The pitfalls of MRI evaluation for anterior mediastinal cystic lesions are as follows: first, we acknowledge the limitation of T2-weighted images for evaluating benign cystic lesions. Due to variable contents within benign cystic lesions, such as hemorrhage, T2 signal intensity may be variable. Second, owing to extensive necrosis and cystic changes, the T2 shine-through effect may be seen on diffusion-weighted images (DWI), and small solid portions might be missed on enhanced images. Therefore, both enhancement and DWI with apparent diffusion coefficient values should be considered. An algorithm will be suggested for the diagnostic evaluation of anterior mediastinal cystic lesions, and finally, a management strategy based on MRI features will be suggested.

Pseudomyxoma peritonei (PMP) is a rare manifestation of primary mucinous neoplasms. We report two rare cases of PMP originating from mucinous primary ovarian neoplasms. The case series discusses the cases of female patients aged 86 and 52 years who presented with worsening dyspepsia, abdominal distension, pelvic pain, and altered bowel habits. Both of the patients underwent evaluation comprising cancer antigen-125 (CA-125) levels, ultrasound (US) examination of the abdomen and the pelvis, tumor markers, cytological evaluation, and contrast-enhanced computed tomography (CECT) of the pelvis and abdomen. Patients were diagnosed to have pseudomyxoma peritonei arising from mucinous ovarian tumors. Patients were referred to the surgical department and were successfully managed with repeated removal of mucinous material. The present case report highlights the significant radio-pathologic characteristics of PMP, which originated from mucinous ovarian tumors.

UNASSIGNED: The prenatal detection of an intrathoracic cyst during the first trimester of pregnancy is an exceedingly rare condition. In this report, we describe a case of first-trimester intrathoracic cyst causing cardiac dextroposition, which resolved by 24 weeks\' gestation.
UNASSIGNED: A 5-mm intrathoracic cyst causing cardiac dextroposition was detected during the routine sonographic scan performed at 12 weeks + 2 days. The cyst remained stable in size until 20 weeks and was no longer identified during focused fetal echocardiography at 24 weeks.
UNASSIGNED: Our case demonstrates that a first-trimester intrathoracic cyst can have a benign course, either by remaining stable in size or even undergoing complete resolution during the second trimester. A focused sonographic examination should therefore be undertaken as follow-up to determine the final prognosis of these lesions.
UNASSIGNED: The etiology of intrathoracic cysts detected in the first trimester is unclear and could represent a resolving pericardial cyst.