Fine-needle aspiration of lipoblastoma: Cytological, molecular, and clinical features: Fine-Needle Aspiration of Lipoblastoma

A rare case of giant mesenteric lipoblastoma causing an abdominal mass in an 8-month-old child

INTRODUCTION AND IMPORTANCE

Giant mesenteric lipoblastoma (LB) is a rare and benign tumor derived from adipocytes. It may imitate malignant tumors, and its diagnosis is challenging before surgery. The diagnosis can be guided by imaging studies but cannot be confirmed. Just a few cases of lipoblastoma originating from the mesentery are reported in the literature.

CASE PRESENTATION

We present a case of a rare giant lipoblastoma arising from the mesentery of an 8-month-old boy who consulted our emergency department for an incidentally discovered abdominal mass.

CLINICAL DISCUSSION

LB is most common in the first decade of life, with a high incidence in boys. LBs are generally found in the trunk and extremities. Intra-abdominal locations are rare; however, intraperitoneal tumors generally reach larger dimensions.

CONCLUSIONS

Tumors that arise in the abdomen are usually larger and may be discovered by physical exam as an abdominal mass and may cause compression symptoms.

A Giant Compressive Mesenteric Lipoblastoma Initially Suspected to Be Abdominal Malignancy: A Report of a Rare Case in a Nine-Month-Old Infant

Lipoblastoma is a rare benign soft tissue neoplasm rising from embryonic white adipose tissue known as lipoblast that keeps proliferating during the postnatal period. Although lipoblastomas are benign, they often grow rapidly. Most lipoblastomas are asymptomatic at presentation; they can present as a growing painless palpable mass and progressive symptoms of various organ compression depending on localization. A giant mesenteric lipoblastoma is a rare case with only a few cases reported. An infant with large intraabdominal masses may present preoperative diagnostic difficulties. Differential diagnoses are broad and may include sarcomas, germ-cell tumors, lipomas, lymphomas, hepatoblastomas, Wilm's tumors, and neuroblastomas. Thorough clinical, radiological, and pathological investigations are ultimately required to obtain a definitive diagnosis. Regardless of location, the treatment of choice for lipoblastoma is complete surgical resection. All patients should be followed up for a minimum of five years We report a rare case of a giant compressive mesenteric lipoblastoma that was initially suspected as abdominal malignancy in a nine-month-old infant. As physicians, we must always consider the underlying cause as well as the malignant or benign nature of a growing mass to treat the patient appropriately.

Lipoblastoma in one adult and 35 pediatric patients: Retrospective analysis of 36 cases

Lipoblastoma is a rare benign mesenchymal neoplasm that typically occurs at various sites in infants and children but may also occur in adults. Thus, differential diagnoses are often performed. To understand this tumor type, the present study described clinicopathological features, diagnosis and differential diagnosis of different morphological lipoblastomas. A single-institution retrospective review of 36 lipoblastoma cases diagnosed between 2015 and 2021 was performed. Formalin-fixed paraffin-embedded tissue was used for S-100, CD34, P16 and desmin immunohistochemistry analysis, along with rapid fluorescence in situ hybridization (FISH) detection with pleiomorphic adenoma gene 1 (PLAG1). The 36 cases included 14 females and 22 males [age range, 7 days to 33 years (median, 16.5 years); 28 patients were aged ≤3 years] and the tumors were located in the trunk (n=16), limbs (n=12), head and neck (n=6), and perineum (n=2). Histologically, lipoblastomas were divided into classic (n=15), lipoma-like (n=13) and myxoid (n=8) subtypes. They comprised lobules of mature adipose tissue of varying size and a fine capillary network surrounded by mucinous stroma. Single- or multivesicular lipoblasts positive for S-100 (29/36, 81%) were observed, with occasional mature adipocytes. Peripheral vessels and cytoplasm of primitive mesenchymal cells were diffusely positive for CD34 (36/36, 100%), whereas primitive mesenchymal cells and striated muscle tissue were positive for desmin (26/36, 72%). Most tumor cells were negative while only few were positive for P16 (8/36, 22%). FISH revealed PLAG1 breakage and rearrangement in 24/32 (75%) patients. In total, 28 patients were followed up post-operatively (range, 2-84 months; median, 41 months; 3 patients relapsed and 8 were lost to follow-up). In conclusion, diagnosis of a typical lipoblastoma is not difficult and PLAG1 breakage detection is key for the diagnosis.

Pleomorphic liposarcoma with liver metastasis diagnosed by combined fine-needle aspiration cytology and core-needle biopsy

Pleomorphic liposarcoma (PLPS) is the rarest liposarcoma subtype, with high‐local recurrence and metastasis rates. Fine‐needle aspiration cytology (FNAC) is successfully used in the diagnosis of primary or metastatic soft tissue tumors, but liver metastases of PLPS diagnosed by FNAC have never been reported. The cytological diagnosis depends on the identification of lipoblasts with sharply defined cytoplasmic vacuoles indenting and distorting the nucleus in the context of a pleomorphic tumor and in a proper clinical and imaging context. Despite its aggressive behavior, hematogenous liver metastases are rare, with just one case reported in literature. A case of PLPS liver metastasis and concomitant primary tumor diagnosed by FNAC and core needle biopsy is herein described.

A Cheek Mass in a 5-Year-Old Child

OBJECTIVES

To describe the management of a 5-year old female with a painless, mobile cheek mass.

METHODS

A retrospective chart review of presentation, imaging, pathology and management.

RESULTS

Magnetic resonance imaging showed a heterogenous mass with solid and lipomatous components. The mass was a lipoblastoma on histopathology and was excised completely with no evidence of recurrence.

CONCLUSIONS

The diagnosis and management of a cheek mass in a child is challenging. Imaging is important but not diagnostic. Surgical excision is the primary management of a lipoblastoma.

A Rare Case of Giant Mesenteric Lipoblastoma in a 6-Year-Old Child and Review of the Literature

Giant mesenteric lipoblastoma is a rare benign tumor arising from the adipocytes. It can mimic malignant tumors, and its diagnosis is difficult before surgery. Imaging studies could lead the diagnosis but not confirm it. Those tumors arising in the abdomen are usually larger and can cause symptoms of compression. Surgical excision is the treatment of choice, and a long-term follow-up is necessary to detect local recurrences. Only a few cases of lipoblastomas arising from the mesentery are reported in literature. We present a case of a rare giant lipoblastoma arising from the mesentery of a 6-year-old girl, with a history of postprandial abdominal pain.

Fine needle aspiration cytology of paediatric soft tissue tumours highlighting challenges in diagnosis of benign lesions and unusual malignant tumours

INTRODUCTION

The type of soft tissue lesions seen in children differs from that seen in adults. The role of fine needle aspiration (FNA) cytology in their diagnosis is not well documented.

AIM

To study the cytopathological spectrum of paediatric soft tissue tumours to highlight uncommon benign and malignant lesions and the challenges in their diagnosis.

METHODS

A 3-year retrospective audit of all paediatric soft tissue FNA cytology cases from 2015 to 2017 was performed. Smears were reviewed along with cell block immunocytochemistry and follow-up histopathology of resected specimens wherever available.

RESULTS

A total of 127 cases were reviewed, which included 72 benign and 55 malignant soft tissue tumours. Uncommon lesions described herein are myxoid fibrohistiocytic tumour, myxoma, lipoblastoma, Bednar tumour, malignant extra-renal rhabdoid tumour and desmoplastic small round cell tumour. Histopathology confirmation was available in 25 cases, out of which 16 cases were completely concordant. In eight cases, all benign diagnoses, histopathology provided more accurate subtyping than FNA. These included cases of lipoblastoma, myxoma and spindle cell haemangioma.

CONCLUSION

FNA cytology of paediatric soft tissue tumours is accurate in classifying lesions as benign or malignant which helps in treatment planning. Immunocytochemistry performed on cell blocks is useful for subtyping malignant lesions.

Follow-up outcomes of pediatric patients who underwent surgical resection for lipoblastomas or lipoblastomatosis: a single-institution experience with a systematic review and meta-analysis

PURPOSE

The objective of this study was to examine the long-term outcomes of pediatric patients who underwent surgical resection for lipoblastoma and lipoblastomatosis (LB/LBM).

METHODS

A single-center retrospective study of pediatric patients with LB/LBMs seen between 1991 and 2015 was conducted. A systematic review, including studies published prior to late August 2018, was performed. Using a random effect meta-analysis, pooled weighted proportions and unadjusted odds ratios (OR) with 95% confidence intervals (CI) were calculated.

RESULTS

The retrospective study included 16 patients, while the systematic review included 19 published studies consisting of 381 patients. Among 329 (82%) patients with follow-up information, the pooled recurrence rate was 16.8% (95% CI 10.9-23.5%; I² = 59%). The reported time to recurrence ranged from < 1 to 8 years. Recurrence risk was greater for incomplete (n = 34) than complete resection (n = 150): OR 11.4 (95% CI 3.0-43.6; I² = 43%). LBMs (n = 35) had a greater recurrence risk than LBs (n = 116): OR 5.5 (95% CI 1.9-15.9; I² = 0%). Recurrences were higher for studies with approximately ≥ 3 years of follow-up versus studies with < 3 years of follow-up.

CONCLUSION

Recurrences are more likely to occur with LBMs and/or incomplete resection. Follow-up beyond 3-5 years should be considered given that the recurrence risk appears to be greater in the long-term.

Infantile Abdominal and Pelvic Lipoblastomas: A Case Series

Lipoblastomas are rare benign mesenchymal tumors that arise from embryonal fat cells.

They are usually discovered in infants and children under 3 years of age, and mostly occur in the trunk (from 10 to 60%, depending on the study) and extremities (from 40 to 45%), while head and neck localizations are rare, with only five cases described to date.

We report on three cases of lipoblastomas in infants younger than 4 years, with unusual localizations: one intra-abdominal, discovered during a laparotomy for an intussusception; one pelvic, misdiagnosed as an ovarian mass; and one gluteal with a pelvic extension.

All children underwent magnetic resonance imaging as preoperative workup. All tumors were completely resected with free surgical margins and ultrasonographic follow-up was uneventful for all patients.

The diagnostic utility of retroperitoneoscopic tissue biopsy for unresectable retroperitoneal lesions excluding urogenital cancers

Background

Retroperitoneal tumors are an uncommon disease known to consist of a diverse group of benign and malignant neoplasms. Treatment of unresectable retroperitoneal lesions requires pathological diagnosis. Here, we report the utility and safety of retroperitoneoscopic biopsy for unresectable retroperitoneal lesions excluding urogenital cancers.

Methods

We analyzed 47 patients consisting of 23 (49%) and 24 (51%) cases that underwent retroperitoneoscopic tissue biopsy and open biopsy, respectively. The clinicopathological features, including postoperative complications, were compared between the two groups.

Results

Tumor pathology was diagnosed successfully with a single operation in all patients. Malignant pathology (68%) was more common than benign pathology (32%). The most common pathology was malignant lymphoma, which accounted for about 50% of all cases. There was no significant difference with respect to the age, sex, tumor size, presence of tumor-related symptom, histopathology, operative time, and complications. Three (13%) of 23 patients in the retroperitoneoscopic biopsy group received percutaneous needle biopsy before laparoscopic excisional biopsy because the evaluation of needle cores failed to confirm subclasses of diagnosed pathologies. One patient was converted to open surgery just after the initiation of operation due to severe adhesion of adjacent structures. We had two cases with iatrogenic urinoma due to ureteral injury after retroperitoneoscopic biopsy.

Conclusions

We conclude that retroperitoneoscopic biopsy is a safe and useful tool for benign and malignant retroperitoneal lesions, in comparison to open biopsy. It is critical to carefully examine the preoperative imaging for the location of tumors, especially those close to the renal pelvis and ureter.

Mesenchymal Neoplasms of the Genitourinary System: A Selected Review with Recent Advances in Clinical, Diagnostic, and Molecular Findings

Mesenchymal neoplasms of the genitourinary (GU) tract often pose considerable diagnostic challenges due to their wide morphologic spectrum, relative rarity, and unexpected incidence at GU sites. Soft tissue tumors arise throughout the GU tract, whether from adventitia surrounding or connective tissues within the kidneys, urinary bladder, and male and female genital organs. This selected article focuses on a subset of these lesions, ranging from benign to malignant and encompassing a range of patterns of mesenchymal differentiation, where recent scholarship has lent greater insight into their clinical, molecular, or diagnostic features.

Applications of Ancillary Testing in the Cytologic Diagnosis of Soft Tissue Neoplasms

Soft tissue neoplasms are diagnostically challenging, although many advances in ancillary testing now enable accurate classification of fine-needle aspiration biopsies by detection of characteristic immunophenotypes (including protein correlates of molecular alterations) and molecular features. Although there are many useful diagnostic immunohistochemical markers and molecular assays, their diagnostic utility relies on correlation with clinical and morphologic features, judicious application, and appropriate interpretation because no single test is perfectly sensitive or specific. This review discusses applications of ancillary testing for commonly encountered soft tissue neoplasms in cytopathologic practice in the context of a pattern-based approach.