S1587 Unusual Explanation for Elevated Alkaline Phosphatase: A Case Report

Abstract

INTRODUCTION: Gastroenterologists often evaluate abnormal alkaline phosphatase (ALP) levels – which can indicate liver dysfunction. This case describes persistent ALP levels that were alleviated by resection of a sex cord-stromal tumor (SCT) with presentation confounded by cholecystitis. To our knowledge this case highlights the first case of this tumor type being implicated in elevated ALP. CASE DESCRIPTION/METHODS: A 52-year-old female presented with right upper quadrant pain, elevated ALP and suspected biliary obstruction. Upon examination, symptoms were attributed to a dilated common bile duct and gallstones with ALP levels of 794 units/L. After ERCP and laparoscopic cholecystectomy, ALP improved (764 units/L) without normalizing, all other symptoms resolved. Six months later the patient presented with left lower quadrant pain, palpable mass and rising ALP (1,108 units/L). Abdominal and pelvic CT showed a 14 × 12 × 16 cm complex solid heterogeneously enhancing pelvic mass. An exploratory laparotomy was performed with a bilateral salpingo-oophorectomy, pelvic washings and omentectomy, a 15 cm left ovarian tumor was discovered and removed. ALP normalized following these procedures. On gross examination the tumor had a variegated gray-brown-yellow solid cut surface. Histologically the tumor grew in diffuse sheets and vague nests with areas of necrosis. The tumor demonstrated grade 1-2 nuclear atypia with high mitotic activity and no Reinke crystals. A diagnosis of SCT not otherwise specified was rendered. The tumor invaded the mesovarium connective tissue and sigmoid colon serosa. No obvious disease was found outside the pelvis and pelvic washings were negative for malignancy. The tumor was staged at IIb and characterized as malignant given the infiltration into surrounding tissue, large size, high mitotic activity, necrosis and grade 1-2 atypia (Figure 1). DISCUSSION: This case is significant due to the unusual presentation of this rare tumor. The elevated ALP improved after gallstone removal and cholecystectomy but never normalized, likely the ALP at initial presentation was related to the undiagnosed SCT. Following SCT resection the ALP normalized quickly suggesting the tumor resection prompted normalization (Figure 2). In conclusion, this case represents an unusual presentation of a gynecological malignancy with significantly elevated ALP confounded by an initial presentation consistent with biliary tract disease. Only after successful removal of the tumor did the elevated ALP resolve.Figure 1.: Hematoxylin and eosin stained sections of this steroid cell tumor demonstrating malignant features including cytologic atypia (a, ×10), high mitotic activity including an atypical mitosis (b, ×20) and areas of necrosis (c, ×10).Figure 2.: Graphical representation of reported total measured ALP levels. Date of collection is shown on the x-axis and concentration in Units/L on the y-axis. The green text highlights date of cholecystectomy. The red vertical line and red text highlight date of NOS SCT resection. ALP normal range: 45–117 units/L.