A Rare Case of Carcinoma Cuniculatum Involving the Larynx in Association with a Saccular Cyst

Abstract

Carcinoma cuniculatum (CC), a rare, well-differentiated variant of squamous cell carcinoma, is uncommon in head and neck sites but when it does occur is most common in the oral cavity. Here we report a rare case of CC involving the larynx. A 49-year-old man presented with 10 months of worsening hoarseness and, despite multiple biopsies, no diagnosis of malignancy could be established. Eventual partial excision of the lesion and histologic review of prior specimens confirmed the diagnosis of CC. Focally, a transition to respiratory epithelium indicated the presence of an associated saccular cyst. Total laryngectomy was performed and 6 months later the patient is free of disease. Only two prior cases of CC have been reported in the larynx. Diagnosis of CC is challenging given the low grade histologic features and awareness of this entity for both treating physicians and the pathologist is important to reach a diagnosis of malignancy. This case highlights the challenges in diagnosis of CC, especially in unusual locations and when associated with other lesions such as a saccular cyst. Awareness of this rare tumor type combined with close communication between treating clinicians, radiologists and pathologists should allow earlier diagnosis and treatment.

Fig. 1

Laryngoscopic strobe image of the patient’s laryngeal mass involving the bilateral larynx prior to total laryngectomy

Fig. 2

Excision of neck mass (hematoxylin and eosin, ×40). Histologic image of the tumor showing burrow-like channels of bland squamous epithelium. Centrally, these channels showed cystic dilation and often contained keratin debris

Fig. 3

Area of papillary growth pattern (hematoxylin and eosin, ×40). Focally the tumor showed areas of prominent papillary growth with a bland squamous lining further complicating the diagnosis of an invasive malignancy

Fig. 4

Focal atypia and angulated tumor nests (hematoxylin and eosin, ×40). Focally the tumor showed areas of increased atypia and infiltrative, angulated tumor nests more in keeping with a conventional squamous cell carcinoma

Fig. 5

Laryngectomy showing associated saccular cyst. a Sections of the laryngectomy had large cystic spaces with bland squamous lining and keratin debris. Focally a transition to respiratory epithelium was seen in the lower aspect indicating the presence of an associated saccular cyst (hematoxylin and eosin, ×40). b Higher power view showing the focal transition from well differentiated squamous cell carcinoma to respiratory type epithelium. Here the respiratory epithelium demonstrated squamous metaplasia but retained several goblet cells (hematoxylin and eosin, ×100)