Inflammatory Myofibroblastic Tumor of the Kidney and Bilateral Lung Nodules in a Child Mimicking Wilms Tumor With Lung Metastases

Anaplastic Lymphoma Kinase (ALK)-Negative Inflammatory Myofibroblastic Tumor of the Kidney in a Nine-Month-Old Girl

An inflammatory myofibroblastic tumor (IMT) is an uncommon, benign tumor of myofibroblastic spindle cells. An IMT can occur in any part of the body. However, involving kidney is exceedingly rare. When this rare entity occurs in children, it becomes incredibly challenging to distinguish this rare entity from other malignancies such as Wilms tumor. Although imaging studies of the abdomen and pelvis add to the diagnosis, however, histological examination and immunohistochemical staining remain the gold standard for the precise diagnosis of this rare entity. To the best of our knowledge, only 48 cases of renal IMT have been published in the medical literature so far. We report the case of a nine-month-old girl who was brought with complaints of hematuria, and later, imaging and histological confirmation revealed an anaplastic lymphoma kinase (ALK)-negative IMT of the kidney.

Twenty children with non-Wilms renal tumors from a reference center in Central Anatolia, Turkey

Background/aim

Non-Wilms renal tumors (NWRTs) are rarely encountered in children. The aim of this study is to determine the treatment strategies, prognosis, outcomes, and survival of children with NWRTs at Erciyes University in Kayseri, Turkey.

Materials and methods

Medical records of all patients (n = 20) treated for NWRTs over a 23-year period (1995–2018) were reviewed retrospectively.

Results

There was male predominance (female/male: 7/13); the median age at diagnosis was 3.2 years old (0.1–13.5 years old). The major histological groups included mesoblastic nephroma (MBN), (n: 5, 25%), malignant rhabdoid tumor (MRT), (n: 5, 25%), renal cell carcinoma, (n: 3, 15%), inflammatory myofibroblastic tumor (n: 2, 10%), multilocular cystic renal tumors (n: 2, 10%), metanephric adenoma (n: 1, 5%), renal neuroblastoma (n: 1, 5%), and bilateral renal Ewing sarcoma/primitive neuroectodermal tumor (ES/PNET) (n: 1, 5%). All of the patients with NWRTs had radical nephrectomy except the child with bilateral renal ES/PNET. Six children died because of progressive disease; the mortality rate was 30% (n: 6).

Conclusion

We have made the first report of bilateral renal involvement of ES/PNET in the English medical literature. Physicians dealing with pediatric renal masses should be alert to the high mortality rate in children with MRT, MBN, and ES/PNET and they should design substantial management plans for NWRTs.

Kidney inflammatory myofibroblastic tumor masquerading as metastatic malignancy: A case report and literature review

BACKGROUND

Inflammatory myofibroblastic tumor (IMT) is a rare mesenchymal tumor that is characterized by spindle cells differentiated from muscle fibroblasts and infiltration of various types of inflammatory cells. IMT can occur at any age and at any anatomic site. The most common location of IMT is the bladder in the genitourinary tract. Only scarce cases of kidney IMT have been reported in the literature.

CASE SUMMARY

A 77-year-old woman, with a history of bilateral renal calculus for 15 years, was admitted to the Department of Urology of our hospital complaining of recurrent painless gross hematuria for one month. The treatment with cephalosporin was ineffective. Computed tomography imaging showed a mixed density and slightly heterogeneously enhanced lesion in the middle pole of the left kidney and ipsilateral adrenal enlargement. The patient underwent surgical treatment by retroperitoneoscopic left radical nephrectomy plus adrenalectomy. A large number of typical spindle cells surrounded by plasma cells and lymphocytes were observed microscopically. Immunohistochemical analyses indicated that these spindle cells were positive for vimentin, cytokeratin (CK), Ki-67, CK7, CD34, and CD31 and were focally positive for CD10 and anaplastic lymphoma kinase (ALK-1). Thus, a diagnosis of IMT was made definitively. The patient recovered well after operation, and no recurrence or metastasis was noted during the 22-mo follow-up.

CONCLUSION

Since kidney IMT is very rare and lacks characteristic clinical manifestation, it is easily misdiagnosed as a malignant tumor before operation. Surgery remains the best choice for diagnosis and treatment, and such cases must be followed carefully because of the uncertain biological behavior of this tumor. This report suggests that renal calculus may be one of the causes of IMT, but further investigation is necessary to prove it.

Imaging of Unusual Renal Tumors

PURPOSE OF REVIEW

Renal masses are a wide entity and a common finding in clinical practice. Detection of these masses has increased in the last years, yet mortality rates have slightly decreased.

RECENT FINDINGS

According to the World Health Organization classification, there are 8 types, 51 subtypes, and a lot more subsequent subclassifications of renal tumors. Histopathological analysis should always be assessed for final diagnosis of theses tumors. However, imaging can be an important diagnostic guidance. The most common diagnoses of renal tumor are clear cell carcinoma, papillary renal cell carcinoma, angiomyolipoma, and transitional cell carcinoma. Nonetheless, a considerable variety of particular tumors can arise from the kidney, challenging the expertise of radiologists and urologists on this subject. The awareness of these unusual entities is vital for professionals working at a complex medical facility with greater volume of patients. We hereby present uncommon renal tumors and its pathological and radiological features.

Inflammatory myofibroblastic tumors in the kidney and abdominal wall mimicking malignancy: A case report

RATIONALE

Inflammatory myofibroblastic tumor (IMT) is uncommon, coexistence of IMTs in the kidney and abdominal wall are more uncommon.

PATIENT CONCERNS AND DIAGNOSIS

We report a 74-year-old female who presented with 6 months history of left flank pain and approximately 5 kg weight loss that were diagnosed as renal cell carcinoma and locally metastatic abdominal wall tumor.

INTERVENTIONS AND OUTCOMES

A left radical nephrectomy and excision of the abdominal wall tumor were done. The pathologic result was IMTs. After follow-up for 66 months, the patient showed no signs of tumor recurrence.

LESSONS

Coexistence of IMTs in the kidney and abdominal wall is extremely rare and is often diagnosed as malignancy. Therefore, IMTs should be considered in the diagnosis of the patient with both kidney and abdominal wall tumors.

Inflammatory myofibroblastic tumour

While initially controversial, the proposal that a subset of inflammatory pseudotumours were myofibroblastic neoplasms is now acknowledged. Inflammatory myofibroblastic tumour is a spindle cell neoplasm of intermediate biological potential that may arise in a wide range of anatomic sites but has a particular propensity for the lung and abdominal soft tissues. Depending on its location, IMT may present with a variety of clinical symptoms and it may also express a variable pathologic phenotype, leading to a broad range of clinical and pathological differentials. Recent discoveries about the molecular signatures of IMT not only provide additional tools to assist in their diagnosis, they also point to possible therapeutic interventions that may transform the management algorithms for patients with this condition.

Complete and Repeated Response of a Metastatic ALK-rearranged Inflammatory Myofibroblastic Tumor to Crizotinib in a Teenage Girl

Inflammatory myofibroblastic tumors (IMT) are rare tumors in children and young adults, considered by the World Health Organization to be intermediate malignancies and rarely metastasizing, with the presence of an anaplastic lymphoma kinase rearrangement in about 50% of the cases. We report the case of a teenager who presented with a metastatic aggressive IMT that was life-threatening despite multiple treatments, and which responded repeatedly to anaplastic lymphoma kinase-targeted crizotinib therapy. Crizotinib induced drastic primary tumor regression, which was sufficient to allow surgical resection and to control distant disease. This case shows that crizotinib is a promising therapy in IMT, even in adolescents and young adults.