169. A 60-year-old man comes to the physician because of a 6-month history of light-headedness, numbness and paresthesias of his hands and feet, and fatigue. Physical examination shows pallor and decreased positional and vibration senses. Laboratory studies show: Hemoglobin Hematocrit Mean corpuscular volume Serum 9 g/dL 27% 102 μm³ Gastrin Intraluminal stomach acid markedly increased markedly decreased The most likely cause of this patient's symptoms is destruction of which of the following labeled areas in the photomicrograph of normal stomach mucosa?

169. A 60-year-old man comes to the physician because of a 6-month history of light-headedness, numbness and paresthesias of his hands and feet, and fatigue. Physical examination shows pallor and decreased positional and vibration senses. Laboratory studies show: Hemoglobin Hematocrit Mean corpuscular volume Serum 9 g/dL 27% 102 μm³ Gastrin Intraluminal stomach acid markedly increased markedly decreased The most likely cause of this patient's symptoms is destruction of which of the following labeled areas in the photomicrograph of normal stomach mucosa?