MIMICKING SOFT TISSUE TUMOUR- SPINDLE CELL LIPOMA

Spindle cell lipomas (SCL) are slow-growing benign adipocyte tumours that are most commonly seen in (1) the upper back, posterior aspect of the neck, and shoulders . Both genders are affected, but it is more (1) prevalent in males between the ages of 40 and 70 . Spindle cell lipoma is a benign tumour that is frequently confused with (1) liposarcoma. SCLs account for approximately 1.5 percent of all lipomatous tumours reported, making them uncommon . They (2) have a morphology similar to other benign and malignant fatty/spindle cell or myxoid lesions . Microscopically, it is a complex mixture of lipocytes and uniform spindle cells embedded in a mucinous matrix and traversed by (2) a variable number of birefringent collagen bres . Due to the unusual presentation and similar morphology of tumours, early diagnosis is critical; thus, diagnosis is based on clinical examination and conrmed by histopathological ndings. Because SCL has a favourable prognosis, wide local (1) excision is the treatment of choice . This is a case report of a 52-year-old male with a similar presentation in the right upper limb.

Histological and Ultrastructural Description of Benign Adipocytic Tumors in Farmed Striped Sea Bream (Lythognathus mormyrus)

Cutaneous neoplasms affecting wild striped bream (Lythognathus mormyrus) have been recorded after their introduction in a marine aquaculture farm in the Adriatic Sea. The tumors were evident on 24% of the reared fish, showing single or multiple nodules, with a diameter ranging between 0.5–4.0 cm. Histologically, all the neoplastic lesions were located in the stratum spongiosum of the dermis and were surrounded by a thin capsule of connective tissue. The tumors were predominantly composed of adipocytes grouped and surrounded by a thin net of fibroblasts and collagen fibers. In some lipomas a mixture of adipocytes and uniform spindle cells were also observed. Fibroblasts and collagen fibers, or spindle cells, showing few mitotic figures were mainly observed in other nodules. Three of the tumors showed bands of cells with elongated nuclei. Five neoplasms differed from the classic spindle cell lipoma due to the presence of scattered giant cells. These cells presented acidophilic abundant cytoplasm with multiple hyperchromatic nuclei showing a concentric “floret-like” arrangement. The tumors were further characterized by ultrastructural observations that allowed ruling out the presence of virus-like particles within the lesions. Histological features of the masses lead to the identification of four prevalent patterns of neoplasms: lipoma, fibrolipoma, spindle cell lipoma (SCL), and atypical spindle cell-like lipoma (ASCL). The different neoplasms could arise from the transformation of mesenchymal cells of dermal origin. To the author’s knowledge, this is the first report describing key differential histological and ultrastructural features of these neoplasms in striped sea bream.

Spindle Cell Lipoma with Ossification Mimicking Atypical Lipomatous Tumor/Well-Differentiated Liposarcoma: A Case Report

Although spindle cell lipoma (SCL) is a subtype of lipoma, the characteristics of SCL are observed in both lipomatous and non-lipomatous tumors. In this article, we present a case of SCL with ossification mimicking atypical lipomatous tumors/well-differentiated liposarcomas (ALTs/WDLs). Considering the findings of magnetic resonance imaging and needle biopsy, which exhibited ALTs/WDLs, marginal resection was performed. Histopathological findings demonstrated mature adipocytes and spindle cells without atypia and no malignant osteoid tissue in the ossified region. In addition, immunohistochemistry (IHC) showed positive staining for CD34, heterogeneous retinoblastoma protein deficiency, and negative staining for mouse double minute 2 homolog (MDM2) and cyclin-dependent kinase. Fluorescence in-situ hybridization showed negative amplification of MDM2. The final diagnosis of the tumor was established using IHC as an extremely rare SCL with ossification.

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.