Dipnech: A Rare Cause of Slow-Growing Pulmonary Nodules in a Dyspnoeic Patient with a History of Breast Cancer

A middle-aged woman undergoing a computed tomography scan while being investigated for a retrosternal goitre, was found to have several solid intrapulmonary nodules of varying sizes with mosaic attenuation of lung parenchyma. After serial radiology follow-up, a radiologist with a special interest in thoracic imaging made the tentative diagnosis of diffuse idiopathic pulmonary neuroendocrine cell hyperplasia (DIPNECH) during discussions at the local multidisciplinary team meeting. Radionuclide imaging was performed to assist in reaching a diagnosis. Uptake of DOTATATE by the pulmonary nodules on a background of mosaic attenuation pattern supported a diagnosis of DIPNECH. Potential secondary metastatic disease from previous breast malignancy confounded a possible earlier diagnosis of DIPNECH, with subsequent diagnostic imaging modalities leading to the rare diagnosis. The patient was treated symptomatically with oral steroids with no improvement, and subsequently with octreotide which significantly improved her condition.

Learning points: Clinical symptoms of diffuse idiopathic pulmonary neuroendocrine cell hyperplasia (DIPNECH) are common to several other respiratory conditions that are found ubiquitously in the community; being aware of this rare condition will help in reaching a diagnosis in a timelier manner.Several potential treatments are described in the literature including steroid therapy, cytotoxic agents and somatostatin analogues, which despite their efficacy have not been demonstrated in studies; however, a small number of case reports such as this one showed an improvement in symptomatology with this treatment.