Solitary Soft-Tissue Metastasis of a Pancreatic Adenocarcinoma 2 Years After Curative Resection: Report of a Rare Case and a Literature Review

Abstract

BACKGROUND Soft-tissue metastases from a primary carcinoma are rare lesions. They often are the first clinical manifestation of a previously unknown malignancy of an advanced stage, but may also be solitary in a setting of a recurrent disease. Generally, they are associated with poor prognosis and may be the source of diagnostic confusion both clinically and pathologically. The primary location of the malignancy is usually lung, breast, kidney, or colon. Soft-tissue metastases from a pancreatic adenocarcinoma are extremely rare. A few cases involving the skin have been described in the literature, and solitary metastasis to the deep soft-tissue (eg, subcutis and skeletal muscle) was reported less than 10 times. CASE REPORT We report the case of a 74-year-old woman who presented with late-onset (recurrent disease), solitary, subcutaneous metastasis in the posterior aspect of the left thigh, deriving from a pancreatic head adenocarcinoma, 2 years after initial treatment with R0 resection (pancreaticoduodenectomy) and adjuvant chemotherapy. We emphasize the rarity of this entity, review the literature, and discuss treatment options. CONCLUSIONS Solitary soft-tissue metastasis from a pancreatic adenocarcinoma after initial curative treatment is very rare. Although hematogenous spread from a pancreatic adenocarcinoma generally has a very poor prognosis, treatment should be individualized according to the patient's history, general condition, and symptoms and the clinical setting in relation to the primary disease.

Figure 1.

Axial T1-weighted MRI sequence depicting a homogenous low signal intensity tumor (white arrow).

Figure 2.

Axial T2-weighted MRI sequence depicting a homogenous high signal intensity tumor (white arrow).

Figure 3.

After injection of Gd-DTPA, the tumor shows strong peripheral enhancement (white arrow) with central hypoattenuation and peritumoral edema (black arrow).

Figure 4.

Intraoperative photo of the tumor located subcutaneously, after mobilization from the surrounding tissue.

Figure 5.

H&E, magnification scale ×100: Neoplastic cells forming adenoid and cribriform tumor clusters, invading surrounding connective tissue with desmoplastic reaction.

Figure 6.

H&E, magnification scale ×200: At higher magnification, the carcinomatous cells consist of eosinophilic cytoplasm, with a high nuclear/ cytoplasmic ratio, and atypical nuclei, in various sizes, with prominent nucleoli.

Figure 7.

H&E, magnification scale ×40: High-grade adenocarcinoma infiltrating fibrous connective and fatty tissue. Green stain indicates the peripheral surgical margin.