Pleomorphic lipoma: A rare entity

Pleomorphic lipoma is a rare neoplasm that is considered as a variant of spindle cell lipoma. It predominantly occurs in the dermis or subcutis of the posterior neck, upper back, and shoulders. Pleomorphic lipoma may clinically present as a slow-growing and well-circumscribed subcutaneous mass. Though it is a benign tumour it may contain atypical cells for which it may mimick sarcoma or other malignant soft tissue tumours. So histopathological diagnosis is vital for preventing unnecessary surgery. Here we report a case of a pleomorphic lipoma on upper back in a 55yr old patient.

The Rapidly Expanding Group of RB1-Deleted Soft Tissue Tumors: An Updated Review

The classification of soft tissue tumors has evolved considerably in the last decade, largely due to advances in understanding the pathogenetic basis of many of these, sometimes rare, tumors. Deletion of Retinoblastoma 1 (RB1), a well-known tumor suppressor gene, has been implicated in the tumorigenesis of a particular group of soft tissue neoplasms. This group of so-called ”RB1-deleted soft tissue tumors” has been rapidly expanding in recent years, currently consisting of spindle cell/pleomorphic lipoma, atypical spindle cell/pleomorphic lipomatous tumor, pleomorphic liposarcoma, myofibroblastoma, cellular angiofibroma, and acral fibromyxoma. Most of these neoplasms, except pleomorphic liposarcoma, are considered benign entities and are mainly described in the older adult population. This article will review the currently known morphological, immunohistochemical, and molecular features of this heterogeneous group of mesenchymal tumors with an emphasis on differential diagnosis.

Giant Pleomorphic Lipoma With Malignant Transformation in the Buttock: a Rare Case Report and Literature Review

Background: Pleomorphic lipoma is a benign tumor, which is often located in the neck, shoulder, and other subcutaneous tissues. Pleomorphic lipoma with malignant transformation in the buttock is rarely reported.Case Presentation: A 53-year-old male attended to our department with a large mass in his buttock that had been present for about one year, leading to difficulty with walking and defecation. Computed tomography (CT) showed a 10. 2 × 8. 3 cm mass with lumpy and mixed low to medium density shadows in the right side of the lower part of the tailbone. Color Doppler ultrasound showed that the skin and subcutaneous tissues of the right buttock were thickened with lymphedema. Pre-operative pathology revealed a large amount of adipose and fusiform fibrous tissues with obvious blood vessels. The patient underwent complete resection of the mass in the right buttock. Postoperative pathology indicated that the tumor was pleomorphic lipoma with malignant transformation. The patient recovered well and was discharged from the hospital at day 12 post-surgery. Follow up at 6 months did not find any symptoms of tumor recurrence.Conclusions: Pleomorphic lipoma with malignant transformation is rare. CT, magnetic resonance imaging (MRI) and histopathology are the main methods used to diagnose pleomorphic lipoma. Complete resection of the tumor is vital to treat giant pleomorphic lipoma successfully.

Telocytes/CD34+ Stromal Cells in Pathologically Affected White Adipose Tissue

We studied telocytes/CD34+ stromal cells (TCs/CD34+SCs) in pathologically affected white adipose tissue after briefly examining them in normal fat. To this aim, we reviewed pathological processes, including original contributions, in which TCs/CD34+SCs are conserved, increased, and lost, or acquire a specific arrangement. The pathologic processes in which TCs/CD34+SCs are studied in adipose tissue include inflammation and repair through granulation tissue, iatrogenic insulin-amyloid type amyloidosis, non-adipose tissue components (nerve fascicles and fibres in neuromas and hyperplastic neurogenic processes) and tumours (signet ring carcinoma with Krukenberg tumour and colon carcinoma) growing in adipose tissue, adipose tissue tumours (spindle cell lipoma, dendritic fibromyxolipoma, pleomorphic lipoma, infiltrating angiolipoma of skeletal muscle and elastofibrolipoma), lipomatous hypertrophy of the interatrial septum, nevus lipomatosus cutaneous superficialis of Hoffman–Zurhelle and irradiated adipose tissue of the perirectal and thymic regions. Two highly interesting issues emerged: (1) whether the loss of CD34 expression in TCs/CD34+SCs is by changes in marker expression or the disappearance of these cells (the findings suggest the first possibility) and (2) whether in some invasive and metastatic malignant tumours, TCs/CD34+SCs that completely surround neoplastic cells act as nurse and/or isolating cells. Further studies are required on adipose tissue TCs/CD34+SCs, mainly in lipomatosis and obesity.

An Unusual Presentation of Pleomorphic Lipoma

Introduction/Objective Pleomorphic lipomas are benign tumors that typically occur in the shoulder, posterior neck, and back. Here, we present a case of a pleomorphic lipoma arising in an unusual location. Methods A 63-year-old male presented with a 1.3 x 1.3 x 0.9 cm enhancing slightly heterogeneous mass in the subcutaneous tissue superficial to the right parotid tail. The mass was biopsied and then excised. Results Histopathologic examination of the biopsy and resection specimens revealed an adipocytic neoplasm composed of mature adipose tissue with admixed spindle cells within a myxoid stroma. Lipoblasts, cellular atypia or increased mitotic figures were absent. Numerous floret-like cells were identified. These floret cells are characteristic of pleomorphic lipoma. The tumor cells were diffusely positive for CD34 and negative for desmin, smooth muscle actin, MyoD1, keratin, SOX10, and Melan-A by immunohistochemistry, consistent with pleomorphic lipoma. Conclusion Pleomorphic lipomas arising from the periparotid adipose tissue are rare. They tend to have a favorable prognosis with low incidence of recurrence if excised with clear margins. Following complete excision, the patient is doing well.