Resident Program - Case of the Month

October 2021 – Presented by Dr. Tahera Iqbal (Mentored by Dr. Joshua Schulman)

Case Discussion

The histological sections show acral skin show a cystic epithelial proliferation, in some areas with cystic space lined by two cell layers of mostly cuboidal cells and in other areas with thickened lining with focal papillary structures. No necrosis is present. The tumor is broadly transected at the base, but the features are consistent with aggressive digital papillary adenocarcinoma, a sweat gland tumor typically occurring in the digit of adult males, with a high local recurrence rate and variable biological behavior. As histologic criteria are generally insufficient to determine prognosis, the term adenocarcinoma is preferred over adenoma (choice C). IHC was performed and the tumor cells are immunopositive for AE1/AE3 and CK7. SMA expression is focal. S100 and CEA are negative, which supports the answer choice D.

Choice A: Spiradenoma- This is a benign adnexal tumor composed of nodules of basaloid cells with ductal differentiation. It can present at any age, however, it is most common in young adults. Microscopically, this tumor is biphasic with 2 cell types: small cells with scant cytoplasm and hyperchromatic nuclei present at the in periphery of the tumor nodules, and larger cells with eosinophilic cytoplasm that is present centrally within the nodules. Papillary structures are not seen in spiradenoma as in digital papillary adenocarcinoma.

Choice B: Malignant Spiradenoma- These tumors are associated with precursor spiradenoma. They can occur anywhere in the body and not limited to the digits. Histologically, like spiradenoma they are biphasic with central basaloid cells and large peripheral cells. They are infiltrative and not well circumscribed, and has prominent atypia, numerous mitotic figures, and variable tumor necrosis. They lack the papillary structures seen in digital papillary adenocarcinoma.

Choice E: Eccrine carcinoma- These tumors are locally aggressive and typically present as a plaque on scalp. Microscopically, these are dermal based tumor with basaloid epithelium and hyperchromatic nuclei. They have an infiltrative growth pattern and perineural invasion is common. They lack the papillary structures seen in digital papillary adenocarcinoma.

References

1. Weingertner N, Gressel A, Battistella M, Cribier B. Aggressive digital papillary adenocarcinoma: A clinicopathological study of 19 cases. J Am Acad Dermatol. 2017 Sep;77(3):549-558.e1. doi: 10.1016/j.jaad.2017.02.028.Epub 2017 May 9. PMID: 28495496
2. Altmann S et al: Aggressive digital papillary adenocarcinoma - a rare malignant tumor of the sweat glands: two case reports and a review of the literature. Clin Cosmet Investig Dermatol. 8:143-6, 2015
3. Frouin E et al: Anatomoclinical study of 30 cases of sclerosing sweat duct carcinomas (microcystic adnexal carcinoma, syringomatous carcinoma and squamoid eccrine ductal carcinoma). J Eur Acad Dermatol Venereol. 29(10):1978-94, 2015
4. Tanese K et al: Malignant eccrine spiradenoma: case report and review of the literature, including 15 Japanese cases. Clin Exp Dermatol. 35(1):51-5, 2010