Robotic excision of pulmonary sclerosing pneumocytoma: a case report

Abstract

We report the first excision of pulmonary sclerosing pneumocytoma (PSP) via a robotic approach. A 20-year-old Caucasian male presented with an incidental 48 mm mass in the right lower lobe. CT-guided biopsy was performed achieving a pre-operative diagnosis of PSP, previously known as pulmonary sclerosing hemangioma. A key histological feature of PSP is the presence of both cuboidal surface cells and stromal round cells and this results in a challenge in diagnosing them on frozen section where they can be easily mistaken for adenocarcinoma or carcinoid tumours. With most PSPs typically presenting as a solitary peripheral nodule, the differential diagnosis is wide. On CT, a predominantly smooth boundary and oval shape is common. The varying proportions of the haemangiomatous, papillary, sclerotic and solid histological patterns result in varying density of 96 to 157 Hounsfield Units, with higher attenuation in angiomatous, isoattenuation in solid and sclerotic and low attenuation in cystic areas. The most common CT signs are a marginal pseudocapsule (50%), overlying vessel (26.3%), halo sign (17.1%) and air-gap sign (2.6%).PSPs also frequently exhibit the tail sign on CT. When one or more of these signs are present, clinicians should be more alert to the possibility of PSP. The majority of reports suggest that PSPs are hypo or intermediate grade lesions on PET. A robotic right lower lobectomy was successfully performed in this case and allowed for the early discharge of the patient and a return to usual activities within 3 weeks. Minimally invasive thoracic surgery via a robotic approach is beneficial to both young, fit patients and may be also advantageous in those with poor lung function or multiple co-morbidities. The challenge with such cases is often with obtaining the correct preoperative radiological and histological diagnosis. Whilst no follow-up guideline for these rare tumours exists, in view of reported malignant potential we advocate close follow-up of patients.