Clear cell sugar tumor of the lung; a systematic review for a rare entity

The diagnosis and management of patients with a clear cell sugar tumor of the lung (CCSTL) is challenging in the clinical practice due to its rarity.

We performed a systematic review on this field according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We sought eligible articles in Medline through January 1st, 2019.

Overall, 104 CCSTL cases were identified and included in the present study. The median age at diagnosis was 52 years (interquartile range 42.5-62.5), whereas the cases were almost equally distributed among males (n=48) and females (n=49). Most of the tumors were asymptomatic (60.7%) and had a benign clinical course (73.3%). Complete tumor resection with a curative intent was the treatment of choice and pathology along with immunohistochemical indices established the diagnosis. However, long-term follow up is recommended, especially among patients with underlying genetic diseases, because disseminated disease may become evident many years following the resection of the primary lesions. Furthermore, an extensive workup for excluding metastasis from another occult primary site is necessary. The updated classification of lung neoplasms has enabled the more frequent reporting of CCSTL cases in the last decade. Interestingly, our time trend analysis showed an increase in malignant cases throughout the years.

Both collaborative multicenter studies and basic research on the underlying pathogenetic mechanisms are deemed necessary in order to optimize the diagnosis and personalize the management of patients with this rare entity.