To the Editor:
We agree with Dr. O.P. Sangüeza that a membranous subtype of basal cell adenocarcinoma of the salivary gland can histologically closely resemble cylindroma. It is of interest that two patients with basal cell adenocarcinoma of the salivary gland also had coexisting dermal cylindromas of the scalp (1). There are two lines of evidence against Dr. Sangüeza's interpretation that our tumor represents a basal cell adenocarcinoma rather than a malignant cylindroma. The gross and microscopic examination showed that the tumor was based on the dermis and subcutis and that the parotid gland was only secondarily superficially invaded. This conclusion was also supported by the imaging studies. We mentioned in our article that the tumor contained well-formed glandular lumina. Their presence can be best appreciated in Fig. 4. Many of them are lined by a characteristic double row of epithelium and resemble ducts (Fig. 1, herein). Identical ductlike lumina are often detected in dermal cylindromas (2), and they were not described in basal cell adenocarcinomas. Basal cell adenocarcinoma only exceptionally contains conspicuous small lumina that resemble tiny cystic spaces rather than ducts (3,4).
Ludvik R. Donner, M.D., Ph.D.; Tibor Ruff, M.D.; Jaime A. Diaz, M.D.
Departments of Pathology and Otolaryngology; Scott & White Clinic and Memorial Hospital; Scott, Sherwood and Brindley Foundation; Texas A&M University Health Science Center; College of Medicine; Temple, Texas
1. Ellis GL, Wiscovitch JG. Basal cell adenocarcinoma of the major salivary glands. Oral Surg Oral Med Oral Pathol
2. Crain RC, Helwig EB. Dermal cylindroma (dermal eccrine cylindroma). Am J Clin Pathol
3. Ellis GL, Auclair PL. Basal cell adenocarcinoma. In: Ellis GL, Auclair PL, Gnepp DR, eds. Surgical pathology of the salivary glands
. Philadelphia: W.B. Saunders, 1991:441-54.
4. Atula T, Klemi PJ, Donath K, Happonen RP, Joensuu H, Grenman R. Basal cell adenocarcinoma of the parotid gland: a case report and review of the literature. J Laryngol Otol