Fine‐needle aspiration cytology of metastatic eccrine porocarcinoma

Abstract

Eccrine porocarcinoma (EP), although rare, is widely recognized as the most common malignant sweat gland tumor. EP typically grows slowly and usually is cured by surgical excision with clear margins. An elevated mortality rate, however, is observed when regional lymph nodes are involved. We herein describe cytohistologic findings in a case of metastatic EP. An 86-year-old man with a history of EP of the left lateral ankle and squamous cell carcinoma in situ (Bowen's disease) of the penis presented with enlarged left inguinal lymph nodes. A superficial fine-needle aspiration (FNA) was performed and demonstrated a hypercellular sample with discohesive clusters and/or individual tumor cells. The tumor cells were round or oval with most of the cells showing dense, refractile cytoplasm. Intracytoplasmic vacuoles were readily appreciated in some of the cells. Nuclear enlargement, high N/C ratio, nuclear hyperchromasia, bi- and multinucleation, and prominent nucleoli were seen. A diagnosis of metastatic eccrine porocarcinoma was rendered. Enlarged retroperitoneal lymph nodes were detected and CT-guided left retroperitoneal core biopsy was performed 1 week later. The biopsy revealed features consistent with metastatic eccrine porocarcinoma.

Fine‐needle aspiration findings of metastatic porocarcinoma

“…The previously reported characteristic cytological features of metastatic porocarcinoma are summarized in Table I. [4][5][6] Although multinucleated tumor cells were not observed in the present case, the cytological features of the present case were similar to those previously reported (Table I). The most peculiar and characteristic cytological finding of the present case is the presence of glandular formation by neoplastic cells.…”

“…The most peculiar and characteristic cytological finding of the present case is the presence of glandular formation by neoplastic cells. Glandular formation is one of the distinguishing histopathological findings of porocarcinoma, as well as intracytoplasmic vacuoles, 6 and this feature was observed in both the original and metastatic lesions of the present case. Glandular formation was mentioned in only one previous cytological report by Blandamura et al 4 The cytological features of porocarcinoma are characteristic but not specific.…”

“…There have been three previously reported cases of metastatic porocarcinoma diagnosed using FNA cytology, [4][5][6] and this is the fourth one that described the cytological features of FNA of metastatic porocarcinoma. The previously reported characteristic cytological features of metastatic porocarcinoma are summarized in Table I.…”

Fine‐needle aspiration cytology in primary cutaneous tumors

“…In cases of nodular hidradenoma, the lack of pale vacuolated cells, and abundance of a single cell population, which leads to diagnostic difficulties has been documented by other authors as well . Till date, scattered case reports on cytomorphology of eccrine porocarcinomas are available in literature . The case in our series, appears to be a rare case of eccrine poroma with detailed cytomorphologic and histologic correlation.…”

“…2 Till date, scattered case reports on cytomorphology of eccrine porocarcinomas are available in literature. 10,11 The case in our series, appears to be a rare case of eccrine poroma with detailed cytomorphologic and histologic correlation. On FNAB a suggestion of benign skin adnexal tumor was given, on retrospective review the cell morphology was suggestive of eccrine differentiation and features to suggest malignancy were not noted.…”