Recurrent Giant Cell Fibroblastoma in an Infant: A Diagnostic Challenge.

Background: Giant cell fibroblastoma (GCF) shows a wide spectrum of morphological patterns which may lead to a misdiagnosis of sarcoma. Case Report: This 14- month- old baby was referred to us for recurrent left scrotal embryonal rhabdomyosarcoma (ERMS), first diagnosed at 8 months, status post chemotherapy. Review of previous histology, cytology (with frequent multinucleated floret type giant cells but without cross striations) and immunohistochemistry resulted in the change of diagnosis to GCF. It was re-excised, recurred at 20 months of age, and was again re-excised. The morphology was the same in both recurrences as the original. Conclusion: Despite chemotherapy, the histology of multiple recurrences for GCF remained the same as the original. Cytologically, identification of the multinucleated floret like giant cells without cross striations was helpful in differentiating this lesion from embryonal rhabdomyosarcoma.

Recurrent giant cell fibroblastoma: Malignancy predisposition in Kabuki syndrome revisited.

Kabuki syndrome is a genetic condition characterized by distinctive facial phenotype, mental retardation, and internal organ malformations. Mutations of the epigenetic genes KMT2D and KDM6A cause dysregulation of certain developmental genes and account for the multiple congenital anomalies of the syndrome. Eight cases of malignancies have been reported in young patients with Kabuki syndrome although a causative association to the syndrome has not been established. We report a case of a 12-year-old girl with Kabuki syndrome who developed a tumor on the right side of her neck. A relapsing tumor 19 months after initial excision, proved to be giant cell fibroblastoma. Τhis is the first report of giant cell fibroblastoma -a rare tumor of childhood- in a patient with Kabuki syndrome.

Dermatofibrosarcoma protuberans: pathology, genetics, and potential therapeutic strategies.

Dermatofibrosarcoma protuberans (DFSP), the most common dermal sarcoma, is a malignant fibroblastic tumor most frequently arising in middle-aged adults. It is typically a low-grade sarcoma that grows slowly but has a high rate of local recurrence with low metastatic potential. Dermatofibrosarcoma protuberans is characterized by a specific translocation t(17;22)(q22;q13) leading to the formation of COL1A1-PDGFB fusion transcripts. Histologically, DFSP has characteristic morphology, of storiform islands of bland spindle cells, and immunohistochemically, it shows diffuse expression of CD34. However, the morphology and immunoprofile can overlap with a variety of other soft tissue neoplasms. The preferred management of localized disease is wide surgical resection or Mohs micrographic surgery, whereas radiotherapy may be used for margin-positive disease where reexcision is not possible, or for inoperable disease. Dermatofibrosarcoma protuberans is generally regarded as refractory to conventional chemotherapy. Treatment options for systemic disease have been previously limited, but the PDGFßR, KIT, and ABL inhibitor imatinib is now an option for effective systemic therapy. Continued insight into the tumorigenic molecular changes generated by the fusion oncogene may lead to further specific targeted treatments. We review DFSP, discussing the morphologic spectrum and variants, immunohistochemistry, molecular genetic findings, potential targeted treatments, and the differential diagnosis.

Infantile Hemangioma Mimics Dermatofibrosarcoma Protuberans.

Infantile hemangiomas are commonly encountered at all levels of medical practice. Clinicians should be aware of their typical clinical history and findings in order to expedite early diagnosis and management. It is also necessary to be aware of differential diagnoses that may mimic infantile hemangiomas but have a more concerning prognosis. The objective of this report is to describe the clinical case of one such mimic, dermatofibrosarcoma protuberans. This report highlights key clinical findings of infantile hemangiomas, while also identifying "red flags" that necessitate urgent additional investigations and referral to a multidisciplinary team. Additionally, key features in the management of both infantile hemangiomas and extremity masses are discussed.

Pediatric dermatofibrosarcoma protuberans: A clinicopathologic and genetic analysis of 66 cases in the largest institution in Southwest China.

Background: Dermatofibrosarcoma protuberans (DFSP) is an uncommon cutaneous tumor in children. Most published articles are sporadic or small series and lack systematically molecular analyses. The aim of our study is to better understand the clinicopathologic and genetic features of these rare lesions. Methods: All patients diagnosed with DFSP aged ≤ 18 years were retrospectively reviewed from January 2006 to May 2022. Results: A total of 66 cases (32 male and 34 female patients) were identified, with ages ranging from 0.3 to 18 years (median, 13 years). Tumor locations predominantly occurred on the trunk (38/66, 57.6%), followed by the extremities (20/66, 30.3%) and head/neck (8/66, 12.1%). Histological findings revealed classic (41/66, 62.1%), myxoid (4/66, 6.1%), pigmented (6/66, 9.1%), plaque-like (3/66, 4.5%), giant cell fibroblastoma (GCF; 6/66, 9.1%), and fibrosarcomatous (6/66, 9.1%) variants of DFSP. Immunochemistry revealed minority tumors (9/66, 13.6%) showing patchy or negative staining for CD34. Fluorescence in situ hybridization (FISH) indicated that 49 of 53 tested cases including all detected biopsy specimens (11/11) contained COL1A1-PDGFB fusion, in which the average copy number gain of COL1A1-PDGFB was 0.68. There were four cases negative for COL1A1-PDGFB rearrangement, one of which was found to harbor a novel COL3A1-PDGFB fusion by next-generation sequencing (NGS). Treatment for 63 patients comprised 40 marginal excisions and 23 wide local excisions (WLEs), including 1 with imatinib therapy. Follow-up information was available on 49 patients with a duration of 12-161 months (median, 60 months). Fourteen patients developed tumor recurrence, all with initial marginal excisions. The others survived with no evidence of disease. Conclusions: This study of pediatric DFSP indicates certain discrepancies in clinicopathologic characteristics between children and adults. The majority of pediatric DFSPs contain COL1A1-PDGFB fusion, the same as their adult counterparts. The COL3A1-PDGFB chimerism might be associated with the special morphology of GCF, which needs further investigation. FISH is valuable in biopsy tissues and cases with atypical CD34 immunostaining, while supplementary NGS could be helpful to identify the cytogenetically cryptic DFSP. Overall, an urgent accurate diagnosis is needed to formulate an optimal therapeutic strategy in the pediatric population.

Rare tumors in pediatric age group: Single center experience from Saudi Arabia.

Rare pediatric tumors are heterogeneous group containing a variety of histopathological diseases, they represent approximately 10% of all childhood cancers. These rare tumors had a diversity of histology and clinical behaviors that pose different challenges to the investigators. Exploring different pediatric rare tumors. The data were reviewed, retrospectively, through the medical records of seven rare pediatric diseases between 2012 and 2019. Giant cell fibroblastoma (GCF) presented as painless swelling in the trunk, positive for CD34 with PTEN gene mutation. Neuroglial heterotopic tissue presented in 7 days old girl with facial asymmetry and bulging in the oral cavity, maximal de-bulking was done, histopathology was positive for GFAP and S100p. Left side neck mass, surgically excised revealed non-metastatic salivary grand mucoepidermoid carcinoma. Follow up without any chemotherapy or radiotherapy for 5 years with complete remission. Mesenchymal chondrosarcoma (MCS) presented in maxillofacial bones by persistent nasal bleeding, HEY1-NCOA2 fusion gene confirmed the diagnosis. Extra-osseous Ewing sarcoma (EES) presented as rubbery painless swelling in the scalp with fusion transcript involving EWSR1-FL11. Juvenile xanthogranuloma (JXG) presented by butter fly like skin patch in the face with foamy histiocytes in upper dermis with few Touton giant cells, extensive systemic involvement of lung and bone marrow. Metastatic ovarian choriocarcinoma with choriocarcinoma syndrome received induction two different lines of chemotherapy and consolidated with autologous stem cell transplant. Seven pediatric rare tumors, with different aspects of challenges in diagnosis and management, despite the absence of formal protocols and rarity of other center experiences.

Ultrasound and MRI Findings of Giant Cell Fibroblastoma in the Abdominal Wall: Radiologic-Pathologic Correlations.

Giant cell fibroblastoma (GCF) is a rare soft-tissue sarcoma of fibroblastic origin. To the best of our knowledge, only one brief description of the MRI findings of GCF exists in the pathologic literature. Herein, we report a case of histologically proven GCF in a 3-year-old boy who underwent ultrasonography and MRI of a superficial mass in the abdominal wall.

Nonepithelial Tumors and Tumor-like Lesions of the Skin and Subcutis in Children.

This overview of mesenchymal tumors presenting in the skin and/or subcutis in children brings together the range of neoplasms and hamartomas which are seen in this age-group. It is not surprising from the perspective of the pediatric or general surgical pathologist that vascular anomalies, including true neoplasms and vascular malformations, are the common phenotypic category. Since there is considerable morphologic overlap among these lesions, clinicopathologic correlation may be more important than for many of the other mesenchymal tumors. The skin and subcutis are the most common sites of clinical presentation for the infantile myofibroma which is the most common of fibrous mesenchymal tumors in children. Several of the other mesenchymal tumors are more common adults-like dermatofibrosarcoma protuberans, but nonetheless have an important presence in children, even as a congenital neoplasm. A lipomatous tumor in a young child should be considered as a possible manifestation of an overgrowth syndrome.

FNA diagnosis of giant cell fibroblastoma: a case report of an unusual pediatric soft tissue tumor.

Giant cell fibroblastoma (GCF) is a rare pediatric soft tissue tumor, which exists on a spectrum with dermatofibrosarcoma protuberans (DFSP). Histologic features are well established for these entities; however, cytologic findings have not been well characterized. We report for the first time a case of GCF, confirmed by cytogenetics, with mixed DFSP features. In this case of an 8-month-old boy, a fine needle aspiration specimen showed a low-grade spindle cell tumor, with oval to spindled cells dispersed singly and in patternless groups, and with occasional giant cells. Subsequent histologic features were consistent with GCF, which is an uncommon, CD34 positive, soft tissue neoplasm with a distinct molecular aberration. This case emphasizes the differential diagnosis in pediatric soft tissue tumors and stresses the unique features of GCF.