A tale of 3 testes? A rare presentation of lipoblastoma with a novel karyotype

Lipoblastoma Arising in the Head and Neck: A Clinicopathologic Analysis of 20 Cases

BACKGROUND

Lipoblastomas (LPBs) are benign adipocytic neoplasms believed to recapitulate the development of embryonal fat.

METHODS

We investigated the clinicopathologic and immunohistochemical features of 20 lipoblastomas arising in the head and neck in 18 patients.

RESULTS

Patients included 6 males and 12 females (1:2 ratio) with age at diagnosis ranging from 4 months to 28 years. Tumors occurred more commonly in the neck (12, 66.7%) and less commonly in the forehead, scalp, and tongue (2, 11.1%). Tumor size ranged from 1.4 to 6.0 cm (median 5.0 cm). Two patients, a 4-month-old female and 3-year-old male, had local recurrence of neck tumors at 4 months and 3 years after excision, respectively. Microscopically, tumors had a lobulated growth pattern and consisted of adipocytes at varying stages of differentiation. In addition to the classical histologic features, lipoma-like and myxoid variants constituted 45% of cases. Metaplastic elements, including brown fat and cartilage, were identified in two cases.

CONCLUSIONS

LPBs arising in the head and neck region are not uncommon and occurred at a rate of 9% in our cohort. They should be kept in the differential diagnosis when a fatty tumor is encountered in an older child or occurring at an unusual location.

Intrascrotal lipoblastoma in adulthood

This case report describes the case of a 37-year-old man that noticed an intrascrotal right mass with 1 month of evolution. During physical exam presented with a large mass at the inferior portion of the right testicle, clearly separated from the testicle, with a tender consistency and mobile. An ultrasound was performed that showed a solid and subcutaneous nodular lesion, extra testicular, heterogeneous, measuring 7.2 cm. Pelvic magnetic resonance imageMRI showed a lesion compatible with a lipoma. The patient was subjected to surgical excision of the lesion by scrotal access, having histology revealed a lipoblastoma (LB) of the scrotum. Histological diagnosis was obtained by microscopic characteristics (well-circumscribed fatty neoplasm) and immunohistochemistry (stains for CD34, S100 protein and PLAG1 were positive; stains for MDM2 and CDK4 were negative). LB is extremely rare after adolescence in any location, being this first described case of intrascrotal LB described in adulthood.

Intrascrotal lipoblastoma: report of a case and the review of literature

Intrascrotal lipoblastoma is a rare pediatric benign soft tissue neoplasm, and only 11 cases have been reported. The accurate preoperative diagnosis is difficult because of its rarelity and the similarity with the other soft tissue tumors. Among them, accurate preoperative diagnosis had been made in only one case. Thus, almost all of the cases had required inguinal mass excision (and orchidectomy in one case). In this paper, we discuss the accurate preoperative diagnosis of intrascrotal lipoblastoma and subsequent simple tumorectomy via minimal invasive scrotal skin incision, in 1-year-old boy. On physical examination, intrascrotal extra-testicular lobulated mass was palpated on the right scrotum. An ultrasonography revealed the well-circumscribed, iso-echoic, scant blood-flow, and lobulated tumors with each lobules of 1 to 4 cm in diameter, and the tumor located outside of the tunica vaginalis testis. The serum values of alpha-fetoprotein (AFP) and beta-human chorionic gonadotropin (b-hCG) were within normal limit. The preoperative diagnosis of intrascrotal lipoblastoma was made, and the mass was excised via minimal scrotal incision. The right testicle and epididymis were normal. The lesion consisted of the distinct two lobulated tumors, and microscopic examination confirmed the diagnosis of intrascrotal lipoblastoma. The postoperative course was uneventful without evidence of recurrence. A rare intrascrotal lipoblastoma is seldom made accurate preoperative diagnosis; however, the accurate preoperative suspicion of this tumor leads to the minimal invasive tumorectomy via scrotal skin incision and favorable postoperative recovery without recurrence.

Undifferentiated myxoid lipoblastoma with PLAG1-HAS2 fusion in an infant; morphologically mimicking primitive myxoid mesenchymal tumor of infancy (PMMTI)--diagnostic importance of cytogenetic and molecular testing and literature review

Lipoblastoma is a benign myxoid neoplasm arising in young children that typically demonstrates adipose differentiation. It is often morphologically indistinguishable from primitive myxoid mesenchymal tumor of infancy (PMMTI), which is characterized by a well-circumscribed myxoid mass with a proliferation of primitive mesenchymal cells with mild cytologic atypia. PMMTI occurs in the first year of life and is known to have locally aggressive behavior. No specific genetic rearrangements have been reported to date. In contrast, the presence of PLAG1 (Pleomorphic Adenoma Gene 1) rearrangement is diagnostic for lipoblastoma. We hereby demonstrate the combined application of multiple approaches to tackle the diagnostic challenges of a rapidly growing neck tumor in a 3-month-old female. An incisional tumor biopsy had features of an undifferentiated, myxoid mesenchymal neoplasm mimicking PMMTI. However, tumor cells showed diffuse nuclear expression by immunohistochemical (IHC) stain. Conventional cytogenetic and fluorescence in situ hybridization (FISH) analyses as well as next generation sequencing (NGS) demonstrated evidence of PLAG1 rearrangement, confirming the diagnosis of lipoblastoma. This experience warrants that undifferentiated myxoid lipoblastoma can mimic PMMTI, and the combination of cytogenetic and molecular approaches is essential to distinguish these two myxoid neoplasms. Literature on lipoblastomas with relevant molecular and cytogenetic findings is summarized. Our case is the first lipoblastoma diagnosed with a PLAG1 fusion defined by NGS technology.

[Intrascrotal lipoblastoma in childhood: diagnostic strategies and therapy planning]

Based on a case report of an intrascrotal lipoblastoma in childhood, we present the preoperative diagnostic algorithm and the main differential diagnoses in testicular and paratesticular tumors as well as their surgical management. An 8-week-old infant was admitted with a scrotal tumor known since birth. MRI showed a pinnate vessel supply, originating in the left internal iliac artery. The tumor was exposed operatively and could be completely removed. Intrascrotal lipoblastoma are rare. Like most testicular and paratesticular tumors in childhood lipoblastomas are benign. Today ultrasound and Doppler sonography are basic tools for diagnosis and surgical planning in testicular and scrotal tumors in childhood. In some cases MRI can provide additional important information for surgical planning. In contrast to adults testis sparing surgery is favoured in children.

Intrascrotal lipoblastoma: a report of two cases and a review of the literature

Lipoblastomas are rare benign mesenchymal tumors of fetal white fat tissue appearing most commonly in children under 3 years of age, and usually affecting the extremities. Only nine cases of intrascrotal lipoblastoma have been reported to our knowledge, and although they are benign, in one case an orchidectomy was performed. We describe two new cases of intrascrotal lipoblastoma, and review the literature.

Cytogenetic analysis in the diagnosis and management of lipoblastomas: results from a single institution

BACKGROUND

Lipoblastomas are rare, benign, soft tissue tumors that occur primarily in young children. Treatment includes complete excision and surveillance for recurrence. Lipoblastomas can be indistinguishable from other benign lipomatous tumors and liposarcomas. Cytogenetic analysis can provide the definitive diagnosis in questionable cases, because benign and malignant lipomatous tumors exhibit specific nonrandom cytogenetic abnormalities. The purpose of the present study was to discuss the disease management and outcomes in a large contemporary group of patients with lipoblastoma.

MATERIALS AND METHODS

A retrospective chart review of patients diagnosed with lipoblastoma presenting from 2000-2011 was conducted. The data from these patients were compared with data from a previously published historical group of patients (1985-1999) from the same children's hospital.

RESULTS

We identified 37 patients in the contemporary cohort group and compared them with 25 patients from the historical group. The tumor involvement sites were similar. The current cohort group had a lower recurrence rate, although this might have been underestimated owing to a shorter follow-up period (median 1.4 y, range 2 wk to 11.0 y). Preoperative imaging findings led to an incorrect diagnosis in 62% of the patients. Cytogenetic analysis was used to help determine the final diagnosis in 50% of the cases. In 39% of cases, translocations involved the long arm of chromosome 8, the most common anomaly in lipoblastoma.

CONCLUSIONS

Lipoblastomas are rare tumors in young children that can be misclassified as other malignant or benign lipomatous tumors with markedly different outcomes and treatments. We recommend that cytogenetic analysis be routinely used for all pediatric lipomatous tumors to provide an accurate diagnosis and guide appropriate therapy and follow-up.