Dados do Trabalho

Título

GIANT LIPOSARCOMA IN LOWER LIMB SYNCHRONIC TO KIDNEY CANCER: A CASE REPORT

Apresentação do caso

A 79-year-old man admitted to the oncology service for a 7-year evolution of a left thigh tumor. On examination, a large, soft, painless mass on the left thigh. MRI showed a heterogeneous lipomatous mass in the medial and posterior portions of the left thigh, measuring 30cm, and close to the neurovascular bundle. Abdominal CT showed two expansive lesions with heterogeneous post-contrast enhancement in the middle and lower thirds of the left kidney, calcifications, and intermingled hematic content. He underwent a tumor biopsy in the thigh, which showed mature adipose tissue, and decided to complete tumor resection. Intraoperatively, tumor infiltration of the sciatic nerve was noted, opting to section the lesion to preserve the sciatic nerve, due to low-grade biopsy. AP revealed atypical lipomatous tumor/well-differentiated liposarcoma (LSBD), lipoma-like subtype, 38cm in the longest axis, and compromised margins. Referred to hypofractionated radiotherapy, totaling 66 Gy, and to urology for evaluation of kidney injury. A new CT showed the expansive lesions in the middle and lower thirds of the left kidney, suggesting primary renal neoplasm, measuring 4.2x3.6cm and 5.8x4.2cm; and lipomatous lesion on the right thigh. Performed radical nephrectomy and retroperitoneal lymphadenectomy. AP exhibited clear cell renal cancer (CRCC), margins, and free lymph nodes. Currently, asymptomatic and awaiting imaging tests for the reassessment of a mass in the right thigh, suggestive of a new liposarcoma.

Discussão

There are 4 subtypes of liposarcoma: LSBD, dedifferentiated, myxoid, and pleomorphic. LSBD has an insidious course, making it difficult to distinguish lipoma, especially in the lower limbs. In this way, the biopsy is performed for diagnosis; however, when it is inconclusive or presents benign characteristics, and the suspicion of malignancy persists, must be performed complete excision for diagnostic validation, as in the present case. Treatment is based on total surgical resection, and radiotherapy plays a role in cases of compromised margins. The case reported is also multiple primary neoplasms, a rare situation in oncology, with synchrony between LSBD and CRCC.

Comentários Finais

Liposarcomas are usually LSBD and do not evolve with metastases, despite the chance of tumor dedifferentiation. Thus, when there is no complete tumor excision, adequate follow-up should be instituted and suspicious lesions investigated at a distance, also considering the hypothesis of multiple primary neoplasias.

Palavras Chave

Liposarcoma; Surgical Oncology; Kidney Neoplasms