Gye-Yeon Lim

Pilomatricomas in children: imaging characteristics with pathologic correlation

BackgroundAlthough pilomatricoma commonly occurs in children, there is still a poor understanding of the imaging characteristics of pilomatricoma and lack of agreement regarding its imaging findings and histopathologic features.ObjectivesTo characterize the radiologic appearance of pilomatricomas on US, CT, and MR and to correlate the imaging findings with histopathologic features.Materials and methodsThe imaging findings of 47 pilomatricomas on US (n = 17), CT (n = 31), and MR (n = 5) were retrospectively evaluated. Pathologic specimens of all cases were reviewed and compared with imaging findings.ResultsAll lesions were well-circumscribed, subcutaneous nodules with partial attachment to the overlying skin. On US, the lesions were mostly hyperechoic with posterior acoustic shadowing and hypoechoic rim. On CT, they appeared as enhancing soft-tissue masses with varying amounts of calcification. MR findings were internal reticulations and patchy areas on T2-weighted images and contrast-enhanced T1-weighted images, corresponding to edematous stroma on pathology. Peritumoral inflammatory changes and connective capsule on pathology were well correlated with imaging findings.ConclusionPilomatricoma should be considered when US or CT shows a well-defined hyperechoic or calcific nodule in subcutaneous fat attached to the skin in children. MR images may be helpful in diagnosis. Pathologic findings are well correlated with imaging findings.

Subcutaneous panniculitis-like T-cell lymphoma in a child: whole-body MRI in the initial and follow-up evaluations

Subcutaneous panniculitis-like T-cell lymphoma (SPTCL) is classified as an unusual subtype of peripheral T-cell lymphoma that preferentially infiltrates the subcutaneous tissue without overt lymph node involvement. SPTCL is particularly rare in children, and there have been only a few case reports describing the US and CT findings of SPTCL. To our knowledge, the use of whole-body (WB) MRI as the initial and follow-up diagnostic method to assess the extent of disease and relapse of SPTCL has not been reported in children. In our case report involving one child, WB MRI was useful as both the initial and follow-up diagnostic method to assess the extent of disease and to monitor the patient’s response to therapy for SPTCL.

Gastrointestinal Complications Following Hematopoietic Stem Cell Transplantation in Children

Gastrointestinal system involvement is one of the principal complications seen in the recipients of hematopoietic stem cell transplantation (HSCT), and it is also a major cause of morbidity and death in these patients. The major gastrointestinal complications include typhlitis (neutropenic enterocolitis), pseudomembranous enterocolitis, viral enteritis, graft-versus-host disease, benign pneumatosis intestinalis, intestinal thrombotic microangiopathy, and post-transplantation lymphoproliferative disease. As these patients present with nonspecific abdominal symptoms, evaluation with using such imaging modalities as ultrasonography and CT is essential in order to assess the extent of gastrointestinal involvement and to diagnose these complications. We present here a pictorial review of the imaging features and other factors involved in the diagnosis of these gastrointestinal complications in pediatric HSCT recipients.

A large infiltrating fibrous hamartoma of infancy in the abdominal wall with rare associated tuberous sclerosis

Tuberous sclerosis is a complex autosomal-dominant neurocutaneous syndrome characterized by hamartomatous malformations of fibrous and connective tissues in various organs. Although various histologic types of soft-tissue masses can occur with tuberous sclerosis, we present a unique case of fibrous hamartoma of infancy presenting as large infiltrating cutaneous and subcutaneous masses in the abdominal wall in a 4-year-old boy with tuberous sclerosis. Although the co-occurrence of tuberous sclerosis and fibrous hamartoma of infancy is very rare, it should be considered in the differential diagnosis of subcutaneous soft-tissue masses found in children with tuberous sclerosis.

Neostigmine for the treatment of acute colonic pseudo-obstruction (ACPO) in pediatric hematologic malignancies

Background Acute colonic pseudo-obstruction (ACPO) refers to dilatation of the colon and decreased bowel motility without evidence of mechanical obstruction. Neostigmine, an acetylcholinesterase inhibitor, has been used in patients in whom supportive therapy failed to resolve ACPO. Here, we report the results of administering neostigmine to treat ACPO in children with hematologic malignancies. Methods Between September 2005 and December 2009, 10 patients (8 male and 2 female) were diagnosed with ACPO at the Department of Pediatrics, Catholic University of Korea. Diagnosis of ACPO was based on typical clinical features as well as colonic dilatation found on abdominal CT imaging. Neostigmine was administered subcutaneously at a dosage of 0.01 mg/kg/dose (maximum 0.5 mg) twice daily for a maximum of 5 total doses. ACPO was determined to be responsive to neostigmine if the patient showed both stool passage and improvement of clinical symptoms. Results The study group included 8 acute lymphoblastic leukemia patients, 1 patient with malignant lymphoma, and 1 patient with juvenile myelomonocytic leukemia. The median age at ACPO diagnosis was 8.5 years (range, 3-14). Overall, 8 patients (80%) showed therapeutic response to neostigmine at a median of 29 hours after the initial administration (range, 1-70). Two patients (20%) showed side effects of grade 2 or above, but none complained of cardiovascular symptoms that required treatment. Conclusion In this study, ACPO was diagnosed most often in late-childhood ALL patients. Subcutaneous neostigmine can be used to effectively treat ACPO diagnosed in children with hematologic malignancies without major cardiovascular complications.

Myxoid chondrosarcoma of the sinonasal cavity in a child: a case report.

Chondrosarcomas are malignant tumors of cartilage that rarely involve the sinonasal region, and myxoid chondrosarcoma is a rare histologic variant of chondrosarcoma that usually occurs in the soft tissue of extremities. Although several case reports and results of small series of chondrosarcomas in the sinonasal region in children are available, myxoid type chondrosarcoma is extremely rare. We recently experienced a case of low grade myxoid chondrosarcoma involving the sinonasal cavity in a 10-year-old boy, and here we report its radiologic-pathologic findings. In this case, chondroid calcification on CT and septal and marginal enhancement on MRI suggested a chondrosarcoma. Whole body PET-CT demonstrated no definite metastatic lesion and a low peak standardized uptake value primary tumor. However, no definite distinguishing imaging features were observed that distinguished low grade myxoid chondrosarcoma from conventional chondrosarcoma.

Complicated duplication cysts on the ileum presenting with a mesenteric inflammatory mass

Mesenteric inflammation caused by complicated duplication cysts rarely occurs. We present and discuss the imaging findings of a mesenteric inflammatory mass caused by complicated duplication cysts in an infant. Sonography showed a complex, echogenic cystic mass occupying the right subhepatic region containing two thick-walled cystic lesions inseparable from the normal bowel loop. On CT images a large, heterogeneously enhancing, hypodense peritoneal mass was observed to infiltrate the mesentery, which contained small cystic masses with enhancing thick walls. At surgery a mesenteric inflammatory mass caused by two complicated duplication cysts was found to be firmly fixed by surface contact with the ileum. A review of the literature relating to the etiologic relationship between a mesenteric inflammatory mass and complicated duplication cysts is presented.

A congenial cutaneous bronchogenic sinus of the abdominal wall in an infant

Cutaneous bronchogenic anomalies are very rare, and we report a child who presented with mucoid discharge from a small opening on her epigastrium that was present since birth. Diagnosis and treatment of congenital bronchogenic anomalies are important because surgical excision is needed to prevent the potential risk of infection and malignant degeneration. To the best to our knowledge, this is the first report of a congenital bronchogenic sinus of the abdominal wall.

Spontaneous gastric perforation in a neonate presenting with massive hydroperitoneum

We report the imaging findings in a case of neonatal spontaneous gastric perforation presenting as massive hydroperitoneum rather than pneumoperitoneum. Plain abdominal radiography showed a diffuse ground-glass opacity with paucity of bowel gas. Subsequent ultrasonography demonstrated numerous echogenic peritoneal fluid collections containing echogenic debris shown at surgery to be due to milk and bile.

Disseminated congenital tuberculosis presenting as peritonitis in an infant

Congenital tuberculosis is a rare disease which is curable after early diagnosis. Making an early diagnosis of tuberculosis in an infant is difficult, however, because of its nonspecific clinical findings. It therefore requires a high index of suspicion. In this paper we report the case of an infant with disseminated congenital tuberculosis involving the chest, liver, spleen, abdominal lymph nodes, mesentery, and peritoneum, and which presented as chylous ascites with peritonitis.