Cranial lesions and maxillofacial asymmetry in an archaeological skeleton from Peru: A paleopathological case of possible trauma-induced epidermal inclusion cysts

Abstract

Background: In 2010, the Lambayeque Valley Biohistory Project recovered the skeletal remains of an elderly adult man who died probably during the late 19 th century in Eten, on the north coast of Peru. This individual's cranium exhibited a constellation of highly unusual lytic cranial lesions spanning the left aspect of the frontal bone, nasal region, and right aspect of the superior orbit. Simultaneously, the midfacial and orbital regions exhibited marked asymmetry. In this paper, we describe these dry bone lesions and evaluate various differential diagnosis. Lesion characteristics and patterning is inconsistent with more familiar pathological processes such as infections (i.e., tuberculosis, treponematosis, and leprosy). Lesion morphology most closely resembles cystic development, such as those produced by an epidermal or dermal cyst. Metastatic processes are also examined, but represent remote diagnostic options. The cyst-like lesion morphology, combined with facial asymmetry may be most consistent with a complex etiology involving development of epidermal inclusion cysts secondary to facial trauma. This case describes a very rarely reported kind of craniofacial lesion in archaeological skeletons, highlights the process of differential diagnosis in paleopathology, and contributes to a more complete accounting of craniomaxillary disorders in the Andean past. Context: An archaeologically recovered 19 th century human skeleton, designated Burial CNS U3-5B, documented from the Colonial-era site of Eten, Peru. Aim: Describe, identify, and provide plausible differential diagnosis of a set of highly anomalous craniofacial lesions. Settings and Design: Meticulous observation, description, and differential diagnosis of dry bone lesions in Burial CNS U3-5B. Materials and Methods: The entire skeleton was visually examined and recorded, using standardized data collection protocols involving detailed skeletal and dental inventories, age and sex estimation, development and growth, anthropometry, and pathological conditions of the skeleton and dentition. Pathological features of the lesions were described in terms of abnormal bone size, abnormal bone formation, and abnormal bone loss. Lesion distribution was then mapped throughout the skeleton. Statistical Analysis Used: None. Results: The individual's cranium exhibited a constellation of highly unusual lytic cranial lesions spanning the left aspect of the frontal bone, nasal region, and right aspect of the superior orbit. The midfacial and orbital regions exhibited marked left-side asymmetry. Conclusions: Lesions appear to be most consistent with epidermal inclusion cysts, perhaps secondary to a well-healed traumatic midfacial injury. Infectious disease processes and cancer metastases are ruled out. Through a process of careful description and differential diagnosis, this study presents plausible diagnosis of a condition rarely encountered in archaeological remains.