Porocarcinoma

Porocarcinoma is a rare malignant skin tumour that has an aggressive behaviour.^[1]

It is also known as eccrine porocarcinoma (abbreviated EPC) and malignant eccrine poroma.^[2]

General

Clinical - based on meta-analysis of 453 cases:

No predominance males versus females.
Aggressive behaviour >30% of cases have metastases at presentation - typically to lymph nodes.

Treatment:

Mass or nodule - typically head and neck (40% of cases) or lower extremity (34% of cases).^[1]

Features:

Ductal/eccrine differentiation:^[2]
- Intracytoplasmic lumens.
- Multicellular ducts with thin esoinophilic layer.
- Lack granular cells and lack decapitated lumens - features of apocrine differentiation.
Features of malignancy:^[2]
- Desmoplastic stromal response.
- Irregular dermis infiltrating cell clusters.
+/-Squamous differentiation.
+/-Basaloid differentiation.

DDx:^[3]

↑ ^1.0 ^1.1 Salih, AM.; Kakamad, FH.; Baba, HO.; Salih, RQ.; Hawbash, MR.; Mohammed, SH.; Othman, S.; Saeed, YA. et al. (Aug 2017). "Porocarcinoma; presentation and management, a meta-analysis of 453 cases.". Ann Med Surg (Lond) 20: 74-79. doi:10.1016/j.amsu.2017.06.027. PMID 28721214.
↑ ^2.0 ^2.1 ^2.2 Luz, Mde A.; Ogata, DC.; Montenegro, MF.; Biasi, LJ.; Ribeiro, LC. (Jul 2010). "Eccrine porocarcinoma (malignant eccrine poroma): a series of eight challenging cases.". Clinics (Sao Paulo) 65 (7): 739-42. doi:10.1590/S1807-59322010000700014. PMID 20668633.
↑ ^3.0 ^3.1 ^3.2 Abarzúa, Á.; Álvarez-Véliz, S.; Moll-Manzur, C.. "Concomitant poroma and porocarcinoma.". An Bras Dermatol 92 (4): 550-552. doi:10.1590/abd1806-4841.20175719. PMID 28954110.
↑ Riera-Leal, L.; Guevara-Gutiérrez, E.; Barrientos-García, JG.; Madrigal-Kasem, R.; Briseño-Rodríguez, G.; Tlacuilo-Parra, A. (2015). "Eccrine porocarcinoma: epidemiologic and histopathologic characteristics.". Int J Dermatol 54 (5): 580-6. doi:10.1111/ijd.12714. PMID 25515648.